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1.
Pestic Biochem Physiol ; 200: 105814, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38582586

RESUMO

To explore active natural products against tobacco powdery mildew caused by Golovinomyces cichoracearum, an extract from the fermentation of endophytic Aspergillus fumigatus 0338 was investigated. The mechanisms of action for active compounds were also studied in detail. As a result, 14 indole alkaloid derivatives were isolated, with seven being newly discovered (1-7) and the remaining seven previously described (8-14). Notably, compounds 1-3 are rare linearly fused 6/6/5 tricyclic prenylated indole alkaloids, with asperversiamide J being the only known natural product of this kind. The isopentenyl substitutions at the 5-position in compounds 4 and 5 are also rare, with only compounds 1-(5-prenyl-1H-indol-3-yl)-propan-2-one (8) and 1-(6-methoxy-5-prenyl-1H-indol3-yl)-propan-2-one currently available. In addition, compounds 6 and 7 are new framework indole alkaloid derivatives bearing a 6-methyl-1,7-dihydro-2H-azepin-2-one ring. The purified compounds were evaluated for their activity against G. cichoracearum, and the results revealed that compounds 7 and 9 demonstrated obvious anti-G. cichoracearum activities with an inhibition rate of 82.6% and 85.2%, respectively, at a concentration of 250 µg/mL, these rates were better than that of the positive control agent, carbendazim (78.6%). The protective and curative effects of compounds 7 and 9 were also better than that of positive control, at the same concentration. Moreover, the mechanistic study showed that treatment with compound 9 significantly increased the structural tightness of tobacco leaves and directly affect the conidiospores of G. cichoracearum, thereby enhancing resistance. Compounds 7 and 9 could also induce systemic acquired resistance (SAR), directly regulating the expression of defense enzymes, defense genes, and plant semaphorins, which may further contribute to increased plant resistance. Based on the activity experiments and molecular dockings, the indole core structure may be the foundation of these compounds' anti-G. cichoracearum activity. Among them, the indole derivative parent structures of compounds 6, 7, and 9 exhibit strong effects. Moreover, the methoxy substitution in compound 7 can enhance their activity. By isolating and structurally identifying the above indole alkaloids, new candidates for anti-powdery mildew chemical screening were discovered, which could enhance the utilization of N. tabacum-derived fungi in pesticide development.


Assuntos
Alcaloides , Aspergillus fumigatus , Neopreno , Nicotiana , Alcaloides Indólicos/farmacologia , Alcaloides Indólicos/química , Alcaloides/farmacologia
2.
Nucleic Acids Res ; 52(6): 2808-2820, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38426933

RESUMO

Chemical modifications in RNAs play crucial roles in diversifying their structures and regulating numerous biochemical processes. Since the 1990s, several hydrophobic prenyl-modifications have been discovered in various RNAs. Prenyl groups serve as precursors for terpenes and many other biological molecules. The processes of prenylation in different macromolecules have been extensively studied. We introduce here a novel chemical biology toolkit that not only labels i6A, a prenyl-modified RNA residue, by leveraging the unique reactivity of the prenyl group, but also provides a general strategy to incorporate fluorescence functionalities into RNAs for molecular tracking purposes. Our findings revealed that iodine-mediated cyclization reactions of the prenyl group occur rapidly, transforming i6A from a hydrogen-bond acceptor to a donor. Based on this reactivity, we developed an Iodine-Mediated Cyclization and Reverse Transcription (IMCRT) tRNA-seq method, which can profile all nine endogenous tRNAs containing i6A residues in Saccharomyces cerevisiae with single-base resolution. Furthermore, under stress conditions, we observed a decline in i6A levels in budding yeast, accompanied by significant decrease of mutation rate at A37 position. Thus, the IMCRT tRNA-seq method not only permits semi-quantification of i6A levels in tRNAs but also holds potential for transcriptome-wide detection and analysis of various RNA species containing i6A modifications.


Assuntos
Isopenteniladenosina , Processamento Pós-Transcricional do RNA , RNA de Transferência , Iodo , Neopreno , RNA de Transferência/metabolismo , Saccharomyces cerevisiae , Análise de Sequência de RNA
3.
J Laryngol Otol ; 138(1): 52-59, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37016896

RESUMO

OBJECTIVE: This study investigated the frequency of ear canal protection use and looked at its influence on external auditory exostosis severity and knowledge about external auditory exostosis among windsurfers and kitesurfers on the German coast. METHOD: This retrospective cross-sectional study interviewed 130 windsurfers and kitesurfers along the German coast on knowledge of external auditory exostosis, exposure time, use of neoprene hoods and earplugs, and otological complaints. Participants underwent bilateral video-otoscopic examination. RESULTS: Knowledge of external auditory exostosis was 'good' or 'excellent' in 78 of 130 (60 per cent) individuals and 'poor' or non-existent in 52 of 130 (40 per cent) individuals. Knowledge was positively correlated with hours of exposure, otological complaints and frequency of ear canal protection use. A significant negative influence of neoprene hood use on external auditory exostosis severity was shown. CONCLUSION: The positive effect of external auditory exostosis knowledge on the frequency of ear canal protection and the reduction of external auditory exostosis risk implies a need for health education on this topic.


Assuntos
Exostose , Neopreno , Humanos , Estudos Transversais , Estudos Retrospectivos , Exostose/epidemiologia , Exostose/prevenção & controle , Meato Acústico Externo , Alemanha/epidemiologia
4.
Hand Surg Rehabil ; 42(1): 69-74, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36336264

RESUMO

Flexion contracture of the proximal interphalangeal joint (PIPJ) is one of the most frequent complications in finger trauma. Orthoses are the most widely used method to optimize total end-range time (TERT). No previous studies showed that an elastic tension orthosis could be applied for longer than 12 h. We aimed to demonstrate that the elastic-tension digital neoprene orthosis (ETDNO) can achieve higher TERT and therefore better range of motion than other elastic-tension orthoses (ETO) described in the literature. A prospective study of treatment of PIPJ flexion contracture included 10 PIP joints in 8 patients who met the selection criteria. They were instructed to use the ETDNO for around 23 h per day as far as possible, during a period of 3 weeks. Patients reported a mean TERT of 20.6 h a day. PIPJ contracture improved by a mean Torque Range of Motion (TROM) of 23.5° at 500 g and 22.9° at 800 g of passive extension force during the 3-week treatment. Based on the results of this study, the ETDNO appears to offer a highly effective approach for improving PIPJ flexion contracture, increasing range of motion in extension. ETDNO's efficacy probably lies in the significantly improved comfort and low-profile design, enabling excellent compliance and thus optimizing TERT. LEVEL OF EVIDENCE: Level III.


Assuntos
Contratura , Luxações Articulares , Humanos , Neopreno , Estudos Prospectivos , Articulações dos Dedos , Contratura/terapia , Aparelhos Ortopédicos
5.
FEBS J ; 289(16): 4981-4997, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35202511

RESUMO

Isoprenoids with reduced Z,E-mixed prenyl groups are found in various organisms. To date, only polyprenol reductases (PR-Dol) involved in dolichol biosynthesis have been identified as enzymes capable of reducing Z,E-mixed prenyl groups. Although C35 -isoprenoids with reduced Z,E-mixed prenyl groups are found in mycobacteria, Z,E-mixed heptaprenyl reductase (HepR) remains unidentified. In the present study, the identification and functional analysis of HepR was performed. No PR-Dol homolog gene was detected in the genome of Mycolicibacterium vanbaalenii. However, a homolog of geranylgeranyl reductase (GGR), which reacts with an all-E prenyl group as a substrate, was encoded in the genome; thus, we analyzed it as a HepR candidate. In vitro enzymatic assay and in vivo gene suppression analysis identified the GGR homolog as HepR and revealed that HepR catalyzes the reduction of ω- and E- prenyl units in Z,E-mixed heptaprenyl diphosphates, and C35 -isoprenoids are mainly biosynthesized using E,E,E-geranylgeranyl diphosphate as a precursor. Thus, it was demonstrated that the Z,E-mixed prenyl reductase family exists in the GGR homologs. To the best of our knowledge, this is the first identification of a new type of Z,E-mixed prenyl reductase with no sequence homology to PR-Dol. The substrate specificity of HepR significantly differed from that of GGR, suggesting that it is a new enzyme. HepR homologs are widely distributed in mycobacterial genomes, and lipid analysis suggests that many strains, including pathogenic species, produce HepR metabolites. The discovery of this new enzyme will promote further research on Z,E-mixed isoprenoids.


Assuntos
Alquil e Aril Transferases , Mycobacterium , Mycobacterium/genética , Neopreno , Oxirredutases/genética , Terpenos
6.
Future Med Chem ; 13(14): 1175-1183, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34013764

RESUMO

Background: PPARγ is known to be a key regulator of metabolism and storage of lipids and glucose and to be implicated in the pathology of severe syndromes like obesity, diabetes, atherosclerosis and cancer. Methods: As a continuation of the authors' studies on oxyprenylated secondary metabolites as effective PPARγ agonists, the authors describe herein the chemical synthesis of natural O-prenyl cinnamaldehydes and cinnamyl alcohols and preliminary data on their in vitro effects on PPARγ transcription. Results: Among the panel of eight compounds tested, three - namely, (2E)-3-(4-((E)3,7-dimethylocta-2,6-dienyloxy)-3-methoxyphenyl)acrylaldehyde, (2E)-3-(4-((E)3,7-dimethylocta-2,6-dienyloxy)-3-methoxyphenyl)prop-2-en-1-ol and boropinal A - exerted activity in a dose-dependent manner. Conclusion:O-prenyl cinnamaldehydes and cinnamyl alcohols have the potential to effectively interact with PPARγ receptor.


Assuntos
Acroleína/análogos & derivados , Neopreno/química , PPAR gama/metabolismo , Propanóis/química , Acroleína/química , Acroleína/farmacologia , Genes Reporter , Células HEK293 , Humanos , PPAR gama/agonistas , PPAR gama/genética , Pioglitazona/química , Pioglitazona/farmacologia , Propanóis/farmacologia , Relação Estrutura-Atividade , Ativação Transcricional/efeitos dos fármacos
7.
Plant J ; 104(3): 693-705, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32777127

RESUMO

Serrulatane diterpenoids are natural products found in plants from a subset of genera within the figwort family (Scrophulariaceae). Many of these compounds have been characterized as having anti-microbial properties and share a common diterpene backbone. One example, leubethanol from Texas sage (Leucophyllum frutescens) has demonstrated activity against multi-drug-resistant tuberculosis. Leubethanol is the only serrulatane diterpenoid identified from this genus; however, a range of such compounds have been found throughout the closely related Eremophila genus. Despite their potential therapeutic relevance, the biosynthesis of serrulatane diterpenoids has not been previously reported. Here we leverage the simple product profile and high accumulation of leubethanol in the roots of L. frutescens and compare tissue-specific transcriptomes with existing data from Eremophila serrulata to decipher the biosynthesis of leubethanol. A short-chain cis-prenyl transferase (LfCPT1) first produces the rare diterpene precursor nerylneryl diphosphate, which is cyclized by an unusual plastidial terpene synthase (LfTPS1) into the characteristic serrulatane diterpene backbone. Final conversion to leubethanol is catalyzed by a cytochrome P450 (CYP71D616) of the CYP71 clan. This pathway documents the presence of a short-chain cis-prenyl diphosphate synthase, previously only found in Solanaceae, which is likely involved in the biosynthesis of other known diterpene backbones in Eremophila. LfTPS1 represents neofunctionalization of a compartment-switching terpene synthase accepting a novel substrate in the plastid. Biosynthetic access to leubethanol will enable pathway discovery to more complex serrulatane diterpenoids which share this common starting structure and provide a platform for the production and diversification of this class of promising anti-microbial therapeutics in heterologous systems.


Assuntos
Diterpenos/metabolismo , Scrophulariaceae/metabolismo , Alquil e Aril Transferases/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Eremophila (Planta)/genética , Escherichia coli/genética , Neopreno/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas , Fosfatos de Poli-Isoprenil/metabolismo , Scrophulariaceae/genética , Nicotiana/genética , Nicotiana/metabolismo , Transferases/genética , Transferases/metabolismo
8.
Nutrients ; 12(7)2020 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-32708388

RESUMO

Prenylflavonoids in the human organism exhibit various health-beneficial activities, although they may interfere with drugs via the modulation of the expression and/or activity of drug-metabolizing enzymes. As intestinal cells are exposed to the highest concentrations of prenylflavonoids, we decided to study the cytotoxicity and modulatory effects of the four main hop-derived prenylflavonoids on the activities and mRNA expression of the main drug-conjugating enzymes in human CaCo-2 cells. Proliferating CaCo-2 cells were used for these purposes as a model of colorectal cancer cells, and differentiated CaCo-2 cells were used as an enterocyte-like model. All the tested prenylflavonoids inhibited the CaCo-2 cells proliferation, with xanthohumol proving the most effective (IC50 8.5 µM). The prenylflavonoids modulated the activities and expressions of the studied enzymes to a greater extent in the differentiated, as opposed to the proliferating, CaCo-2 cells. In the differentiated cells, all the prenylflavonoids caused a marked increase in glutathione S-transferase and catechol-O-methyltransferase activities, while the activity of sulfotransferase was significantly inhibited. Moreover, the prenylflavonoids upregulated the mRNA expression of uridine diphosphate (UDP)-glucuronosyl transferase 1A6 and downregulated that of glutathione S-transferase 1A1/2.


Assuntos
Catecol O-Metiltransferase/genética , Catecol O-Metiltransferase/metabolismo , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Flavonoides/farmacologia , Expressão Gênica/efeitos dos fármacos , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Humulus/química , Neopreno/farmacologia , Propiofenonas/farmacologia , Sulfotransferases/genética , Sulfotransferases/metabolismo , Células CACO-2 , Diferenciação Celular/genética , Proliferação de Células/genética , Flavonoides/isolamento & purificação , Glucuronosiltransferase/genética , Glucuronosiltransferase/metabolismo , Humanos , Neopreno/isolamento & purificação , Propiofenonas/isolamento & purificação
9.
Acc Chem Res ; 53(4): 949-961, 2020 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-32202757

RESUMO

From structure elucidation and biogenesis to synthetic methodology and total synthesis, terpene natural products have profoundly influenced the development of organic chemistry. Moreover, their myriad functional attributes range from fragrance to pharmaceuticals and have had great societal impact. Ruzicka's formulation of the "biogenetic isoprene rule," a Nobel Prize winning discovery now over 80 years old, allowed for identification of higher order terpene (aka "isoprenoid") structures from simple five-carbon isoprene fragments. Notably, the isoprene rule still holds pedagogical value to students of organic chemistry today. Our laboratory has completed syntheses of over two dozen terpene and meroterpene structures to date, and the isoprene rule has served as a key pattern recognition tool for our synthetic planning purposes. At the strategic level, great opportunity exists in finding unique and synthetically simplifying ways to connect the formal C5 isoprene fragments embedded in terpenes. Biomimetic cationic polyene cyclizations represent the earliest incarnation of this idea, which has facilitated expedient routes to certain terpene polycycle classes. Nonetheless, a large swath of terpene chemical space remains inaccessible using this approach.In this Account, we describe strategic insight into our endeavors in terpene synthesis published over the last five years. We show how biosynthetic understanding, combined with a desire to utilize abundant and inexpensive [C5]n building blocks, has led to efficient, abiotic syntheses of multiple complex terpenes with disparate ring systems. Informed by nature, but unconstrained by its processes, our synthetic assembly exploits chemical reactivity across diverse reaction types-including radical, anionic, pericyclic, and metal-mediated transformations.First, we detail an eight-step synthesis of the cembrane diterpene chatancin from dihydrofarnesal using a bioinspired-but not -mimetic-cycloaddition. Next, we describe the assembly of the antimalarial cardamom peroxide using a polyoxygenation cascade to fuse multiple units of molecular oxygen onto a dimeric skeleton. This three-to-four-step synthesis arises from (-)-myrtenal, an inexpensive pinene oxidation product. We then show how a radical cyclization cascade can forge the hallmark cyclooctane ring system of the complex sesterterpene 6-epi-ophiobolin N from two simple polyprenyl precursors, (-)-linalool and farnesol. To access the related, more complex metabolite 6-epi-ophiobolin A, we exploited the plasticity of our synthetic route and found that use of geraniol (C10) rather than farnesol (C15) gave us the flexibility needed to address the additional oxidation found in this congener. Following this work, we describe two strategies to access several guaianolide sesquiterpenes. Retrosynthetic disconnection to monoterpenes, carvone or (-)-linalool, coupled with a powerful allylation strategy allowed us to address guaianolides with disparate stereochemical motifs. Finally, we examine a semisynthetic approach to the illicium sesquiterpenes from the abundant 15-carbon feedstock terpene (+)-cedrol using an abiotic ring shift and multiple C-H oxidation reactions inspired by a postulated biosynthesis of this natural product class.


Assuntos
Técnicas de Química Sintética/métodos , Neopreno/química , Terpenos/química , Terpenos/síntese química
10.
Small GTPases ; 11(3): 220-224, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-29239694

RESUMO

Ras proteins must localize to the plasma membrane (PM) for biological function. The membrane anchor of the K-Ras4B isoform comprises a farnesylated and methylated C-terminal cysteine together with an adjacent hexa-lysine polybasic domain (PBD). Traditionally, polybasic sequences have been thought to interact electrostatically with negatively charged membranes showing no specificity for anionic lipid head groups. By contrast we recently showed that the K-Ras membrane anchor actually exhibits a very high degree of specificity for phosphatidylserine (PtdSer). The selectivity for PtdSer is determined by a combinatorial code comprising the PBD sequence plus the prenyl anchor. Lipid binding specificity is therefore altered by PBD point mutations that in turn modulate signaling output. For example, mutating Lys177 or Lys178 to glutamine switches K-Ras4B lipid affinity from PtdSer to phosphoinositol 4,5-bisphosphate (PIP2). Changing the lipid anchor from farnesyl to geranylgeranyl or the PBD lysines to arginines also changes lipid binding specificity. All-atom molecular dynamics simulations reveal the structural basis for these K-Ras anchor lipid-binding preferences. Here we examine the PM interactions of a series of geranylgeranylated PBD mutants and provide further evidence that the precise PBD sequence and prenyl lipid determines lipid sorting specificity of the K-Ras anchor and hence biological function.


Assuntos
Membrana Celular/metabolismo , Lipídeos/química , Neopreno/metabolismo , Polilisina/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Sítios de Ligação , Humanos , Neopreno/química , Polilisina/química , Polilisina/genética
11.
Ann Surg ; 270(5): 791-798, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31567180

RESUMO

OBJECTIVE: The aim of this study was to assess safety and efficacy of pancreatic duct occlusion (PDO) with neoprene-based glue in selected patients undergoing pancreatoduodenectomy (PD) at high risk of postoperative pancreatic fistula (POPF). BACKGROUND DATA: PD is the reference standard approach for tumors of the pancreaticoduodenal region. POPF is the most relevant complication after PD. PDO has been proposed as an alternative to anastomosis to manage the pancreatic stump. METHODS: A single-center, prospective, nonrandomized trial enrolled 100 consecutive PD for cancer. Patients at high risk for POPF according to Fistula Risk Score (FRS) >15% (≥6 points) were treated with PDO using neoprene glue (study cohort); patients with FRS ≤15% (≤5 points) received pancreaticojejunal anastomosis (PJA: control cohort). Primary endpoint was complication rate grade ≥3 according to Dindo-Clavien Classification (DCC). Other postoperative outcomes were monitored (ClinicalTrials.gov NCT03738787). RESULTS: Fifty-one patients underwent PDO and 49 PJA. DCC ≥3, postoperative mortality, and POPF grade B-C were 25.5% versus 24.5% (P = 0.91), 5.9% versus 2% (P = 0.62), and 11.8% versus 16.3% (P = 0.51) in the study versus control cohort, respectively. At 1 and 3 years, new-onset diabetes was diagnosed in 13.7% and 36.7% of the study cohort versu 4.2% and 12.2% in controls (P = 0.007). CONCLUSIONS: PDO with neoprene-based glue is a safe technique that equalizes early outcome of selected patients at high risk of POPF to those at low risk undergoing PJA. Neoprene-based PDO, however, triples the risk of diabetes at 1 and 3 years.


Assuntos
Neopreno/farmacologia , Fístula Pancreática/prevenção & controle , Neoplasias Pancreáticas/cirurgia , Pancreaticoduodenectomia/efeitos adversos , Pancreaticoduodenectomia/métodos , Adulto , Idoso , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Injeções Intralesionais , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Ductos Pancreáticos/efeitos dos fármacos , Fístula Pancreática/etiologia , Neoplasias Pancreáticas/mortalidade , Neoplasias Pancreáticas/patologia , Estudos Prospectivos , Medição de Risco , Análise de Sobrevida , Adesivos Teciduais/farmacologia , Resultado do Tratamento
12.
Food Chem Toxicol ; 114: 285-291, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29476793

RESUMO

The antioxidant effect of 8PP, a prenylflavonoid from Dalea elegans on Candida albicans biofilms, was investigated. We previously reported that sensitive (SCa) and resistant C. albicans (RCa) biofilms were strongly inhibited by this compound, in a dose-depending manner (50 µM-100 µM), with a prooxidant effect leading to accumulation of endogenous oxidative metabolites and increased antioxidant defenses. In this work, the antifungal activity of high concentrations of 8PP (200-1000 µM), the cellular stress imbalance and the architecture of biofilms were evaluated. Biofilms were studied by crystal violet and confocal scanning laser microscopy (CSLM) with COMSTAT analysis. Superoxide anion radical, the activity of the superoxide dismutase and the total antioxidant capacity were measured. Intracellular ROS were detected by a DCFH-DA and visualized by CSLM; reactive nitrogen intermediates by Griess. An antioxidant effect was detected at 1000 µM and levels of oxidant metabolites remained low, with major changes in the SCa. COMSTAT analysis showed that biofilms treated with higher concentrations exhibited different diffusion distances with altered topographic surface architectures, voids, channels and pores that could change the flow inside the matrix of biofilms. We demonstrate for first time, a concentration-dependent antioxidant action of 8PP, which can alter its antifungal activity on biofilms.


Assuntos
Antifúngicos/farmacologia , Antioxidantes/farmacologia , Biofilmes/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Flavonoides/farmacologia , Neopreno/farmacologia , Antifúngicos/análise , Antioxidantes/análise , Candida albicans/metabolismo , Relação Dose-Resposta a Droga , Flavonoides/análise , Testes de Sensibilidade Microbiana , Neopreno/análise
13.
Cell ; 168(1-2): 239-251.e16, 2017 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-28041850

RESUMO

K-Ras is targeted to the plasma membrane by a C-terminal membrane anchor that comprises a farnesyl-cysteine-methyl-ester and a polybasic domain. We used quantitative spatial imaging and atomistic molecular dynamics simulations to examine molecular details of K-Ras plasma membrane binding. We found that the K-Ras anchor binds selected plasma membrane anionic lipids with defined head groups and lipid side chains. The precise amino acid sequence and prenyl group define a combinatorial code for lipid binding that extends beyond simple electrostatics; within this code lysine and arginine residues are non-equivalent and prenyl chain length modifies nascent polybasic domain lipid preferences. The code is realized by distinct dynamic tertiary structures of the anchor on the plasma membrane that govern amino acid side-chain-lipid interactions. An important consequence of this specificity is the ability of such anchors when aggregated to sort subsets of phospholipids into nanoclusters with defined lipid compositions that determine K-Ras signaling output.


Assuntos
Membrana Celular/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/química , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Membrana Celular/química , Humanos , Lipídeos/química , Modelos Moleculares , Simulação de Dinâmica Molecular , Mutação , Neopreno/química , Neopreno/metabolismo , Domínios Proteicos , Proteínas Proto-Oncogênicas p21(ras)/genética
14.
J Expo Sci Environ Epidemiol ; 27(6): 625-631, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-27578185

RESUMO

Exposure of handlers'/operators' hands is a main route of agricultural pesticides entry into their body. Non-occupational handlers still lack information about appropriate selection of protective gloves to minimize exposure and reduce adverse effects of these chemicals. According to the results of our previous survey, six commercially available, water-resistant gloves commonly used by non-professional gardeners were evaluated for permeation of Acetamiprid, Pirimicarb, and Chlorpyrifos-methyl (Chlorp-m) pesticides by means of in vitro testing. In-use conditions were mimicked as close as possible. Chlorp-m through latex was observed inside the glove from >10 to ⩽15 min; however, Acetamiprid and Pirimicarb through neoprene/latex and all the three pesticides through butyl were not observed inside gloves for the duration of the experiments (the Breakthrough time (BT)>8 h). The 1-h exposure proved the interior glove contamination with Chlorp-m through disposable latex, vinyl, and nitrile gloves (51, 33, and 41% of applied dose (AD), respectively) just as with Acetamiprid and Pirimicarb through latex glove (11 and 14%AD, respectively). However, when storing the used gloves for 4 days after the exposure, no release of the three pesticides from the butyl and Acetamiprid from neoprene/latex gloves was detected. In all other cases, pesticides were found in the interior glove (36-79, 31-63, and 51-81%AD for Acetamiprid, Pirimicarb, and Chlorp-m, respectively). If used repeatedly, gloves contaminated in this way lose their protective function but give the user a false sense of security. The results suggest that (i) water-resistant gloves are not necessarily pesticide resistant; (ii) disposable latex gloves commonly worn by non-professional gardeners provide inadequate protection even for a short-time contact with pesticides; (iii) to assess the efficiency of reusable gloves, not only BT value but also the reservoir/release effect of parent pesticide and its degradation products should be evaluated; and (iv) awareness-raising activities for non-occupational handlers of pesticides should be enhanced.


Assuntos
Exposição Ambiental/análise , Monitoramento Ambiental/métodos , Luvas Protetoras , Permeabilidade , Praguicidas/análise , Agricultura , Humanos , Látex/química , Neopreno/química , Cloreto de Polivinila/química
15.
J Am Soc Mass Spectrom ; 28(4): 704-707, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27785692

RESUMO

Farnesylation and geranylgeranylation are the two types of prenyl modification of proteins. Prenylated peptides are highly hydrophobic and their abundances in biological samples are low. In this report, we studied the oxidized prenylated peptides by electrospray ionization mass spectrometry and identified them by collision-induced dissociation (CID) and electron-transfer dissociation (ETD) tandem mass spectrometry. Modified prenyl peptides were generated utilizing strong and low strength oxidizing agents to selectively oxidize and epoxidize cysteine sulfur and prenyl side chain. We selected three peptides with prenyl motifs and synthesized their prenylated versions. The detailed characteristic fragmentations of oxidized and epoxidized farnesylated and geranylgeranylated peptides were studied side by side with two popular fragmentation techniques. CID and ETD mass spectrometry clearly distinguished the modified version of these peptides. ETD mass spectrometry provided sequence information of the highly labile modified prenyl peptides and showed different characteristic fragmentations compared with CID. A detailed fragmentation of modified geranylgeranylated peptides was compared by CID and ETD mass spectrometry for the first time. Graphical Abstract ᅟ.


Assuntos
Neopreno/química , Peptídeos/química , Espectrometria de Massas em Tandem/métodos , Sequência de Aminoácidos , Compostos de Epóxi/química , Gases/química , Oxirredução , Prenilação
16.
FEBS J ; 283(12): 2369-83, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27129422

RESUMO

Cis-prenyltransferase usually consecutively catalyzes the head-to-tail condensation reactions of isopentenyl diphosphate to allylic prenyl diphosphate in the production of (E,Z-mixed) polyprenyl diphosphate, which is the precursor of glycosyl carrier lipids. Some recently discovered homologs of the enzyme, however, catalyze the nonhead-to-tail condensation reactions between allylic prenyl diphosphates. In this study, we characterize a cis-prenyltransferase homolog from a methanogenic archaeon, Methanosarcina acetivorans, to obtain information on the biosynthesis of the glycosyl carrier lipids within it. This enzyme catalyzes both head-to-tail and nonhead-to-tail condensation reactions. The kinetic analysis shows that the main reaction of the enzyme is consecutive head-to-tail prenyl condensation reactions yielding polyprenyl diphosphates, while the chain lengths of the major products seem shorter than expected for the precursor of glycosyl carrier lipids. On the other hand, a subsidiary reaction of the enzyme, i.e., nonhead-to-tail condensation between dimethylallyl diphosphate and farnesyl diphosphate, gives a novel diterpenoid compound, geranyllavandulyl diphosphate.


Assuntos
Lipídeos/química , Methanosarcina/enzimologia , Neopreno/metabolismo , Transferases/química , Catálise , Clonagem Molecular , Cinética , Lipídeos/biossíntese , Neopreno/química , Especificidade por Substrato , Transferases/genética , Transferases/metabolismo
17.
PLoS One ; 11(4): e0153633, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27088717

RESUMO

PURPOSE: Prenyl ammonium iodides (Amino-Prenols, APs), semi-synthetic polyprenol derivatives were studied as prospective novel gene transfer agents. METHODS: AP-7, -8, -11 and -15 (aminoprenols composed of 7, 8, 11 or 15 isoprene units, respectively) were examined for their capacity to form complexes with pDNA, for cytotoxicity and ability to transfect genes to cells. RESULTS: All the carriers were able to complex DNA. The highest, comparable to commercial reagents, transfection efficiency was observed for AP-15. Simultaneously, AP-15 exhibited the lowest negative impact on cell viability and proliferation--considerably lower than that of commercial agents. AP-15/DOPE complexes were also efficient to introduce pDNA to cells, without much effect on cell viability. Transfection with AP-15/DOPE complexes influenced the expression of a very few among 44 tested genes involved in cellular lipid metabolism. Furthermore, complexes containing AP-15 and therapeutic plasmid, encoding the TIMP metallopeptidase inhibitor 2 (TIMP2), introduced the TIMP2 gene with high efficiency to B16-F10 melanoma cells but not to B16-F10 melanoma tumors in C57BL/6 mice, as confirmed by TIMP2 protein level determination. CONCLUSION: Obtained results indicate that APs have a potential as non-viral vectors for cell transfection.


Assuntos
Compostos de Amônio/farmacologia , DNA/administração & dosagem , Sistemas de Liberação de Medicamentos , Terapia Genética , Melanoma Experimental/terapia , Neopreno/química , Sarcoma Experimental/terapia , Animais , Western Blotting , Sobrevivência Celular , Portadores de Fármacos , Feminino , Técnicas de Transferência de Genes , Técnicas Imunoenzimáticas , Lipossomos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/secundário , Neoplasias Pulmonares/terapia , Melanoma Experimental/genética , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sarcoma Experimental/genética , Sarcoma Experimental/patologia , Transfecção , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
18.
Clin Exp Obstet Gynecol ; 41(5): 525-9, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25864252

RESUMO

PURPOSE OF INVESTIGATION: Pain control and early ambulation are two important postoperative goals. Strategies that decrease morphine use while increasing ambulation have the potential to decrease postoperative complications. In this study the authors sought to determine the effect of an abdominopelvic binder on postoperative morphine use, pain, and ambulation in the first day after surgery. MATERIALS AND METHODS: The authors randomly assigned 75 patients undergoing abdominal gynecologic surgery to either binder or not after surgery. Demographic data and surgical characteristics were collected. Outcome variables included morphine use, pain score, time to ambulation, and number of ambulations. RESULTS: A group at high risk for decreased mobility was identified and the binder increased the number of ambulatory events by 300%, 260%, and 240% in patients with vertical incisions, age over 50 years, and complex surgeries, respectively. Morphine use and pain scores were not significantly different. CONCLUSION: The binder increased ambulations in the subset of patients at the highest risk for postoperative complications: elderly, cancer patients, and vertical incisions. Routine use of the binder may benefit particularly high-risk gynecologic surgical patients.


Assuntos
Parede Abdominal/cirurgia , Procedimentos Cirúrgicos em Ginecologia/métodos , Neopreno/farmacologia , Dor Pós-Operatória/prevenção & controle , Cuidados Pós-Operatórios/métodos , Técnicas de Fechamento de Ferimentos Abdominais , Adulto , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Morbidade/tendências , Medição da Dor , Dor Pós-Operatória/diagnóstico , Dor Pós-Operatória/epidemiologia , Estudos Retrospectivos , Texas/epidemiologia , Resultado do Tratamento
19.
Osteoarthritis Cartilage ; 21(5): 668-75, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23458785

RESUMO

OBJECTIVE: In patients with trapeziometacarpal arthrosis, we tested the hypothesis that there is no difference in arm-specific disability 5-15 weeks after prescription of a pre-fabricated neoprene or a custom-made thermoplast hand-based thumb spica splint with the metacarpophalangeal joint included and the first interphalangeal joint free. METHOD: One hundred nineteen patients with a diagnosis of trapeziometacarpal arthrosis were prospectively randomized to wear either a neoprene or a thermoplast hand-based thumb spica splint. At enrollment, patients completed a set of validated questionnaires. An average of 9 weeks later, patients returned for a second visit. Bivariable analyses assessed factors associated with disability, pain and satisfaction. Analysis was by intention-to-treat. RESULTS: Sixty-two patients (32 with a neoprene and 30 with a thermoplast splint) completed the study, 51 patients (43%) did not return for the second visit, and six did not complete the protocol for other reasons. Non-completers were significantly younger than completers (P < 0.00044). On average completers rated the neoprene splint as more comfortable (P = 0.048), but there were no detectable differences in Disabilities of the Arm, Shoulder and Hand (DASH), change in DASH, pain, satisfaction, pinch or grip strength between the two splint types in our sample. CONCLUSION: When compared to custom-made thermoplast splints, pre-fabricated neoprene hand-based thumb spica splints are, on average, more comfortable, less expensive, and as effective in treating trapeziometacarpal arthrosis. This trial was registered at Clinicaltrials.gov (NCT00438763).


Assuntos
Articulações Carpometacarpais , Neopreno , Osteoartrite/terapia , Plásticos , Contenções , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Desenho de Equipamento , Feminino , Força da Mão , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite/complicações , Osteoartrite/fisiopatologia , Dor/etiologia , Manejo da Dor/métodos , Cuidados Paliativos/métodos , Pacientes Desistentes do Tratamento/estatística & dados numéricos , Satisfação do Paciente , Estudos Prospectivos , Polegar , Trapézio , Resultado do Tratamento
20.
Mol Cell Biol ; 33(7): 1417-29, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23358418

RESUMO

Membrane localization of Rho GTPases is essential for their biological functions and is dictated in part by a series of posttranslational modifications at a carboxyl-terminal CaaX motif: prenylation at cysteine, proteolysis of the aaX tripeptide, and carboxymethylation. The fidelity and variability of these CaaX processing steps are uncertain. The brain-specific splice variant of Cdc42 (bCdc42) terminates in a CCIF sequence. Here we show that brain Cdc42 undergoes two different types of posttranslational modification: classical CaaX processing or novel tandem prenylation and palmitoylation at the CCaX cysteines. In the dual lipidation pathway, bCdc42 was prenylated, but it bypassed proteolysis and carboxymethylation to undergo modification with palmitate at the second cysteine. The alternative postprenylation processing fates were conserved in the GTPases RalA and RalB and the phosphatase PRL-3, proteins terminating in a CCaX motif. The differentially modified forms of bCdc42 displayed functional differences. Prenylated and palmitoylated brain Cdc42 did not interact with RhoGDIα and was enriched in the plasma membrane relative to the classically processed form. The alternative processing of prenylated CCaX motif proteins by palmitoylation or by endoproteolysis and methylation expands the diversity of signaling GTPases and enables another level of regulation through reversible modification with palmitate.


Assuntos
Motivos de Aminoácidos/genética , Lipoilação/genética , Neopreno/metabolismo , Prenilação de Proteína/genética , Proteína cdc42 de Ligação ao GTP/metabolismo , Inibidor alfa de Dissociação do Nucleotídeo Guanina rho/metabolismo , Animais , Encéfalo/metabolismo , Encéfalo/fisiologia , Linhagem Celular , Linhagem Celular Tumoral , Membrana Celular/genética , Membrana Celular/metabolismo , Cisteína/genética , Cisteína/metabolismo , GTP Fosfo-Hidrolases/genética , GTP Fosfo-Hidrolases/metabolismo , Células HEK293 , Células HeLa , Humanos , Rim/metabolismo , Rim/fisiologia , Metilação , Camundongos , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Ligação Proteica , Processamento de Proteína Pós-Traducional , Proteínas Tirosina Fosfatases/genética , Proteínas Tirosina Fosfatases/metabolismo , Proteólise , Células Sf9 , Proteína cdc42 de Ligação ao GTP/genética , Proteínas ral de Ligação ao GTP/genética , Proteínas ral de Ligação ao GTP/metabolismo , Inibidor alfa de Dissociação do Nucleotídeo Guanina rho/genética
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