Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 82.571
Filtrar
1.
Methods Mol Biol ; 2558: 221-252, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36169867

RESUMO

Proper elucidation of drug-target interaction is one of the most significant steps at the early stages of the drug development research. Computer-aided drug design tools have substantial contribution to this stage. In this chapter, we specifically concentrate on the computational methods widely used to develop reversible inhibitors for monoamine oxidase (MAO) isozymes. In this context, current computational techniques in identifying the best drug candidates showing high potency are discussed. The protocols of structure-based drug design methodologies, namely, molecular docking, in silico screening, and molecular dynamics simulations, are presented. Employing case studies of safinamide binding to MAO B, we demonstrate how to use AutoDock 4.2.6 and NAMD software packages.


Assuntos
Química Computacional , Inibidores da Monoaminoxidase , Isoenzimas/metabolismo , Simulação de Acoplamento Molecular , Monoaminoxidase/metabolismo , Inibidores da Monoaminoxidase/química , Inibidores da Monoaminoxidase/metabolismo , Inibidores da Monoaminoxidase/farmacologia , Relação Estrutura-Atividade
2.
Nat Commun ; 13(1): 7200, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36418293

RESUMO

Exquisitely tuned activity of protein kinase C (PKC) isozymes is essential to maintaining cellular homeostasis. Whereas loss-of-function mutations are generally associated with cancer, gain-of-function variants in one isozyme, PKCα, are associated with Alzheimer's disease (AD). Here we show that the enhanced activity of one variant, PKCα M489V, is sufficient to rewire the brain phosphoproteome, drive synaptic degeneration, and impair cognition in a mouse model. This variant causes a modest 30% increase in catalytic activity without altering on/off activation dynamics or stability, underscoring that enhanced catalytic activity is sufficient to drive the biochemical, cellular, and ultimately cognitive effects observed. Analysis of hippocampal neurons from PKCα M489V mice reveals enhanced amyloid-ß-induced synaptic depression and reduced spine density compared to wild-type mice. Behavioral studies reveal that this mutation alone is sufficient to impair cognition, and, when coupled to a mouse model of AD, further accelerates cognitive decline. The druggability of protein kinases positions PKCα as a promising therapeutic target in AD.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Camundongos , Animais , Doença de Alzheimer/metabolismo , Proteína Quinase C-alfa/genética , Proteína Quinase C-alfa/metabolismo , Disfunção Cognitiva/genética , Modelos Animais de Doenças , Peptídeos beta-Amiloides/metabolismo , Isoenzimas
3.
Int J Mol Sci ; 23(21)2022 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-36362078

RESUMO

Phospholipase D (PLD) isoenzymes participate in a variety of cellular functions that are mostly attributed to phosphatidic acid (PA) synthesis. Dysregulation of PLD regulates tumor progression and metastasis, yet little is known about the underlying mechanism. We previously reported on the expression and clinical role of the PLD isoenzymes PLD1 and PLD2 in tubo-ovarian high-grade serous carcinoma (HGSC). In the present study, we investigated the biological function of PLD1 and PLD2 using the OVCAR-3 and OVCAR-8 HGSC cell lines. KO cell lines for both PLDs were generated using CRISPR/CAS9 technology and assayed for exosome secretion, spheroid formation, migration, invasion and expression of molecules involved in epithelial-mesenchymal transition (EMT) and intracellular signaling. Significant differences between PLD1 and PLD2 KO cells and controls were observed for all the above parameters, supporting an important role for PLD in regulating migration, invasion, metastasis and EMT.


Assuntos
Exossomos , Neoplasias Ovarianas , Fosfolipase D , Feminino , Humanos , Apoptose , Carcinoma Epitelial do Ovário , Linhagem Celular Tumoral , Transição Epitelial-Mesenquimal/genética , Exossomos/metabolismo , Isoenzimas , Neoplasias Ovarianas/genética , Fosfolipase D/genética , Fosfolipase D/metabolismo
4.
Medicine (Baltimore) ; 101(45): e31028, 2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36397395

RESUMO

To investigate the changes to the myocardial enzyme profile and its clinical value in patients with different degrees of spleen injury. Of all patients who underwent total splenectomy due to trauma-induced spleen injury from January 2019 to January 2022 were selected, 70 patients with grade III and IV spleen injuries were selected as the experimental group. In addition, 70 patients with grade I and II were selected as control group 1, and another 70 patients as control group 2. The levels of creatine kinase (CK), creatine kinase isoenzyme (CK-MB), lactate dehydrogenase (LDH) in the 3 groups were detected before (T0) and on the 1st day (T1) after surgery, on the 3rd day (T2) and on the 7th day (T3) after surgery, and on the 14th day (T4) after surgery, respectively, to analyze the relationship with the severity of spleen injury. The spleen injury experimental group, control group 1, and control group 2 were all cured and discharged after corresponding treatment, and there was no myocardial infarction within 3 months of hospitalization and discharge follow-up. The experimental group had higher CK, CK-MB, and LDH than control group 1 and control group 2 at the same time point from T0 to T4 (P<.05); the CK and CK-MB of control group 1 were higher than those of control group 2 at the same time points from T0 to T4 (P < .05), the LDH at points T0 to T2 was higher than that of control group 2 (P < .05), and the LDH was lower at points T3 and T4. Compared with T0 in the same group, CK, CK-MB, and LDH at T1 to T4 in the 3 groups were all lower than those at T0 (P < .05). The early peripheral blood myocardial enzyme spectrum of patients with different degrees of spleen injury is increased, and the increase of myocardial enzyme spectrum is positively correlated with the severity of spleen injury, suggesting that patients with traumatic spleen injury may have myocardial damage in the early stage, and should be treated as soon as possible.


Assuntos
Isoenzimas , Baço , Humanos , Baço/cirurgia , Miocárdio , Creatina Quinase Forma MB , Creatina Quinase , L-Lactato Desidrogenase
5.
Int J Mol Sci ; 23(21)2022 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-36361903

RESUMO

Over 10 million people worldwide live with Parkinson's disease (PD) and 4% of affected people are diagnosed before the age of 50. Research on early PD-related pathways is therefore of considerable importance. Peptidylarginine deiminases (PADs) are a family of calcium-activated enzymes that, through post-translational deimination of arginine to citrulline, contribute to changes in protein function, including in pathological processes. Recent studies have highlighted roles for PADs in a range of neurological disorders including PD, but overall, investigations on PADs in Lewy body disease (LBD), including PD, are still scarce. Hence, the current pilot study aimed at performing an immunohistochemistry screen of post-mortem human brain sections from Braak stages 4-6 from PD patients, as well as patients with incidental LBD (ILBD). We assessed differences in PAD isozyme detection (assessing all five PADs), in total protein deimination/citrullination and histone H3 deimination-which is an indicator of epigenetic changes and extracellular trap formation (ETosis), which can elicit immune responses and has involvement in pathogenic conditions. The findings of our pilot study indicate that PADs and deimination are increased in cingulate cortex and hippocampus, particularly in earlier stages of the disease. PAD2 and PAD3 were the most strongly upregulated PAD isozymes, with some elevation also observed for PAD1, while PAD4 and PAD6 increase was less marked in PD brains. Total protein deimination and histone H3 deimination were furthermore increased in PD brains, with a considerable increase at earlier Braak stages, compared with controls. Our findings point to a significant contribution of PADs, which may further aid early disease biomarker discovery, in PD and other LBDs.


Assuntos
Citrulinação , Doença por Corpos de Lewy , Humanos , Desiminases de Arginina em Proteínas/metabolismo , Projetos Piloto , Histonas/metabolismo , Doença por Corpos de Lewy/metabolismo , Corpos de Lewy/metabolismo , Isoenzimas/metabolismo , Hidrolases/metabolismo
6.
Int J Mol Sci ; 23(21)2022 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-36362331

RESUMO

Fungal laccases play important roles in the degradation of lignocellulose. In this study, the laccase producing cotton straw medium for Pleurotus ostreatus was optimized by single-factor and orthogonal experiments, and to investigate the role of Lacc1 gene, one of the laccase-encoding genes, in the degradation of cotton straw lignin, an overexpression strain of Lacc1 gene was constructed, which was analyzed for the characteristics of lignin degradation. The results demonstrated that the culture conditions with the highest lignin degradation efficiency of the P. ostreatus were the cotton straw particle size of 0.75 mm, a solid-liquid ratio of 1:3 and containing 0.25 g/L of Tween in the medium, as well as an incubation temperature of 26 °C. Two overexpression strains (OE L1-1 and OE L1-4) of Lacc1 gene were obtained, and the gene expression increased 12.08- and 33.04-fold, respectively. The results of 1H-NMR and FTIR analyses of significant changes in lignin structure revealed that Lacc1 gene accelerated the degradation of lignin G-units and involved in the cleavage of ß-O-4 linkages and the demethylation of lignin units. These findings will help to improve the efficiency of biodelignification and expand our understanding of its mechanism.


Assuntos
Agaricales , Pleurotus , Pleurotus/genética , Pleurotus/metabolismo , Lacase/metabolismo , Lignina/metabolismo , Agaricales/metabolismo , Isoenzimas/metabolismo , Gossypium/genética , Gossypium/metabolismo
7.
Molecules ; 27(22)2022 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-36431826

RESUMO

Human carbonic anhydrase (CA, EC 4.2.1.1) (hCA) isoforms I, II, IX, and XII were investigated for their inhibitory activity with a series of new Schiff's bases based on quinazoline scaffold 4-27. The hCA I isoform was efficiently inhibited by Schiff's bases 4-6, 10-19, 22-27 and had an inhibition constant (Ki) value of 52.8-991.7 nM compared with AAZ (Ki, 250 nM). Amongst the quinazoline derivatives, the compounds 2, 3, 4, 10, 11, 16, 18, 24, 26, and 27 were proven to be effective hCA II inhibitors, with Ki values of 10.8-52.6 nM, measuring up to AAZ (Ki, 12 nM). Compounds 2-27 revealed compelling hCA IX inhibitory interest with Ki values of 10.5-99.6 nM, rivaling AAZ (Ki, 25.0 nM). Quinazoline derivatives 3, 10, 11, 13, 15-19, and 24 possessed potent hCA XII inhibitory activities with KI values of 5.4-25.5 nM vs. 5.7 nM of AAZ. Schiff's bases 7, 8, 9, and 21 represented attractive antitumor hCA IX carbonic anhydrase inhibitors (CAIs) with KI rates (22.0, 34.8, 49.2, and 45.3 nM, respectively). Compounds 5, 7, 8, 9, 14, 18, 19, and 21 showed hCA I inhibitors on hCA IX with a selectivity index of 22.46-107, while derivatives 12, 14, and 18 showed selective hCA I inhibitors on hCA XII with a selectivity profile of 45.04-58.58, in contrast to AAZ (SI, 10.0 and 43.86). Compounds 2, 5, 7-14, 19-23, and 25 showed a selectivity profile for hCA II inhibitors over hCA IX with a selectivity index of 2.02-19.67, whereas derivatives 5, 7, 8, 13, 14, 15, 17, 20, 21, and 22 showed selective hCA II inhibitors on hCA XII with a selectivity profile of 4.84-26.60 balanced to AAZ (SI, 0.48 and 2.10).


Assuntos
Anidrases Carbônicas , Quinazolinas , Humanos , Quinazolinas/farmacologia , Relação Estrutura-Atividade , Estrutura Molecular , Isoenzimas/metabolismo , Anidrases Carbônicas/metabolismo , Inibidores da Anidrase Carbônica/farmacologia , Anidrase Carbônica I , Anidrase Carbônica II
8.
Molecules ; 27(21)2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36364255

RESUMO

In this work, nine new bromophenol derivatives were designed and synthesized. The alkylation reactions of (2-bromo-4,5-dimethoxyphenyl)methanol (7) with substituted benzenes 8-12 produced new diaryl methanes 13-17. Targeted bromophenol derivatives 18-21 were synthesized via the O-Me demethylation of diaryl methanes with BBr3. Moreover, the synthesized bromophenol compounds were tested with some metabolic enzymes such as acetylcholinesterase (AChE), carbonic anhydrase I (CA I), and II (CA II) isoenzymes. The novel synthesized bromophenol compounds showed Ki values that ranged from 2.53 ± 0.25 to 25.67 ± 4.58 nM against hCA I, from 1.63 ± 0.11 to 15.05 ± 1.07 nM against hCA II, and from 6.54 ± 1.03 to 24.86 ± 5.30 nM against AChE. The studied compounds in this work exhibited effective hCA isoenzyme and AChE enzyme inhibition effects. The results show that they can be used for the treatment of glaucoma, epilepsy, Parkinson's as well as Alzheimer's disease (AD) after some imperative pharmacological studies that would reveal their drug potential.


Assuntos
Acetilcolinesterase , Anidrases Carbônicas , Acetilcolinesterase/metabolismo , Anidrases Carbônicas/metabolismo , Anidrase Carbônica II , Inibidores da Anidrase Carbônica/farmacologia , Metano , Inibidores da Colinesterase/farmacologia , Isoenzimas/metabolismo , Relação Estrutura-Atividade , Estrutura Molecular
9.
Molecules ; 27(22)2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36432129

RESUMO

A novel series of twenty-five rhodamine-linked benzenesulfonamide derivatives (7a-u and 9a-d) were synthesized and screened for their inhibitory action against four physiologically relevant human (h) carbonic anhydrase (CA) isoforms, namely hCA I, hCA II, hCA IX, and hCA XII. All the synthesized molecules showed good to excellent inhibition against all the tested isoforms in the nanomolar range due to the presence of the sulfonamide as a zinc binding group. The target compounds were developed from indol-3-ylchalcone-linked benzenesulfonamide where the indol-3-ylchalcone moiety was replaced with rhodanine-linked aldehydes or isatins to improve the inhibition. Interestingly, the molecules were slightly more selective towards hCA IX and XII compared to hCA I and II. The most potent and efficient ones against hCA I were 7h (KI 22.4 nM) and 9d (KI 35.8 nM) compared to the standard drug AAZ (KI 250.0 nM), whereas in case of hCA II inhibition, the derivatives containing the isatin nucleus as a tail were preferred. Collectively, all compounds were endowed with better inhibition against hCA IX compared to AAZ (KI 25.8 nM) as well as strong potency against hCA XII. Finally, these newly synthesized molecules could be taken as potential leads for the development of isoform selective hCA IX and XII inhibitors.


Assuntos
Inibidores da Anidrase Carbônica , Rodanina , Humanos , Inibidores da Anidrase Carbônica/química , Rodanina/farmacologia , Relação Estrutura-Atividade , Estrutura Molecular , Isoenzimas/metabolismo , Sulfonamidas/química
10.
BMC Plant Biol ; 22(1): 486, 2022 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-36224553

RESUMO

BACKGROUND: The timing of bud break is very important for the flowering and fruiting of longan. To obtain new insights into the underlying regulatory mechanism of bud break in longan, a comparative analysis was conducted in three flower induction stages of two longan varieties with opposite flowering phenotypes by using isobaric tags for relative and absolute quantification (iTRAQ). RESULTS: In total, 3180 unique proteins were identified in 18 samples, and 1101 differentially abundant proteins (DAPs) were identified. "SX" ("Shixia"), a common longan cultivated variety that needs an appropriate period of low temperatures to accumulate energy and nutrients for flower induction, had a strong primary inflorescence, had a strong axillary inflorescence, and contained high contents of sugars, and most DAPs during the bud break process were enriched in assimilates and energy metabolism. Combined with our previous transcriptome data, it was observed that sucrose synthase 6 (SS6) and granule-bound starch synthase 1 (GBSSI) might be the key DAPs for "SX" bud break. Compared to those of "SX", the primary inflorescence, axillary inflorescence, floral primordium, bract, and prophyll of "SJ" ("Sijimi") were weaker. In addition, light, rather than a high sugar content or chilling duration, might act as the key signal for triggering bud break. In addition, catalase isozyme 1, an important enzyme in the redox cycle, and RuBisCO, a key enzyme in the Calvin cycle of photosynthetic carbon assimilation, might be the key DAPs for SJ bud break. CONCLUSION: Our results present a dynamic picture of the bud break of longan, not only revealing the temporal specific expression of key candidate genes and proteins but also providing a scientific basis for the genetic improvement of this fruit tree species.


Assuntos
Proteômica , Sintase do Amido , Acrilatos , Carbono , Catalase/genética , Flores/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Isoenzimas/genética , Ribulose-Bifosfato Carboxilase/genética , Sapindaceae , Sintase do Amido/genética , Açúcares
11.
Ann Palliat Med ; 11(9): 2897-2905, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36217618

RESUMO

BACKGROUND: At present, there are many influencing factors of post-traumatic stress disorder (PTSD) symptoms in patients with acute myocardial infarction (AMI), but based on this, there are few studies on the risk prediction model of PTSD symptoms. The aim of this study was to investigate the risk factors of PTSD symptoms in patients with AMI and to construct a risk prediction model. METHODS: From April 2021 to March 2022, 287 patients were enrolled from a hospital in Shandong Province, China. According to the PTSD Checklist (PCL-C) scores 30 days after discharge, the participants were divided into a PTSD symptoms group (92 cases) and a non-PTSD symptoms group (195 cases). The demographic data, disease factors, treatment factors, and laboratory examination indicators were compared between the 2 groups; independent risk factors were screened out, and a risk prediction model was constructed by logistic regression. Area under the curve (AUC) was used as the internal verification of the model prediction. From April 2022 to June 2022, 72 patients with AMI in a hospital in Shandong Province were selected. PCL-C data were collected 30 days after discharge, and finally external validation of the model was performed. RESULTS: Five factors, including gender [odds ratio (OR) =3.325], diabetes history (OR =2.292), creatine kinase isozyme (OR =1.046), insomnia score (OR =2.045), and fear of disease progression score (OR =1.126) were included to construct the risk prediction model. According to the Hosmer-Lemeshow test, P=0.785. The AUC was 0.910, the maximum value of Youden index was 0.751, the sensitivity was 0.870, the specificity was 0.881, and the accuracy rate of practical application was 67.64%. CONCLUSIONS: The risk prediction model of PTSD symptoms in patients with AMI established in this study is consistent and effective. It can provide a reference for clinical assessment of PTSD symptoms risk in patients with AMI.


Assuntos
Infarto do Miocárdio , Transtornos de Estresse Pós-Traumáticos , Creatina Quinase , Humanos , Isoenzimas , Transtornos Fóbicos , Transtornos de Estresse Pós-Traumáticos/diagnóstico , Transtornos de Estresse Pós-Traumáticos/epidemiologia , Transtornos de Estresse Pós-Traumáticos/etiologia
12.
Medicine (Baltimore) ; 101(39): e30834, 2022 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-36181079

RESUMO

We investigated the factors associated with serum muscle enzyme elevation in patients with Sheehan's syndrome. A total of 48 patients who were newly diagnosed with Sheehan's syndrome were included and divided into 3 groups: Group 1, creatine kinase (CK) ≥ 1000 U/L; Group 2, 140 < CK < 1000 U/L; and Group 3, CK ≤ 140 U/L. Differences in serum muscle enzymes, serum electrolytes, blood glucose and hormones were compared among the 3 groups. A Spearman correlation analysis and multiple linear regression analysis were performed on serum muscle enzymes and the other variables. Four patients in Group 1 underwent electromyography. Fourteen, 26 and 8 patients were divided into Group 1, Group 2, and Group 3, respectively. The levels of plasma osmolality, serum sodium, free triiodothyronine (FT3) and free thyroxine (FT4) in Group 1 were lower than those in Group 3 at admission (P < .05). There were significant differences in CK, CK-MB, aspartate aminotransferase, lactate dehydrogenase, and alpha-hydroxybutyrate dehydrogenase among the three groups (P < .05). CK was correlated with serum sodium (r = -0.642, P < .001), serum potassium (r = -0.29, P = .046), plasma osmolality (r = -0.65, P < .001), FT3 (r = -0.363, P = .012), and FT4 (r = -0.450, P = .002). Moreover, creatine kinase isoenzyme-MB (CK-MB) was correlated with serum sodium (r = -0.464, P = .001) and plasma osmolality (r = -0.483, P < .001). The multiple linear regression showed that serum sodium was independently and negatively correlated with CK (r = -0.352, P = .021). The electromyogram results supported the existence of myogenic injury. Sheehan's syndrome is prone to be complicated by nontraumatic rhabdomyolysis, with both a chronic course and acute exacerbation. Serum muscle enzymes should be routinely measured. For patients with CK levels > 1000 U/L, a CK-MB/CK ratio < 6% can be a simple indicator to differentiate rhabdomyolysis from acute myocardial infarction. Abnormal serum muscle enzymes observed in Sheehan's syndrome may be associated with hypothyroidism and with hyponatremia in particular.


Assuntos
Hipopituitarismo , Rabdomiólise , Aspartato Aminotransferases , Glicemia , Creatina Quinase , Eletrólitos , Humanos , Hipopituitarismo/complicações , Isoenzimas , L-Lactato Desidrogenase , Músculos , Potássio , Rabdomiólise/complicações , Sódio , Tiroxina , Tri-Iodotironina
13.
Curr Top Microbiol Immunol ; 436: 117-143, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36243842

RESUMO

Pleckstrin homology domain leucine-rich repeat protein phosphatases (PHLPP) belong to the protein phosphatase magnesium/manganese-dependent family of Ser/Thr phosphatases. Their general role as tumor suppressors has been documented for over a decade. In recent years, accumulating evidence suggests that PHLPP isozymes have key regulatory roles in both innate and adaptive immunity. In macrophages, PHLPP1 dampens signaling through TLR4 and the IFN-γ receptor by altering cytosolic signaling pathways. Additionally, nuclear-localized PHLPP1 inhibits STAT1-mediated inflammatory gene expression by direct dephosphorylation at Ser 727. PHLPP1 also regulates the migratory and inflammatory capacity of neutrophils in vivo. Furthermore, PHLPP1-mediated dephosphorylation of AKT on Ser 473 is required for both the suppressive function of regulatory T cells and for the pro-apoptotic effects of PHLPP1 in B cell chronic lymphocytic leukemia. In the context of immune homeostasis, PHLPP1 expression is modulated in multiple cell types by inflammatory signals, and the dynamics of its expression have varying effects on the pathogenesis of inflammatory bowel disease and septic shock. In this review, we summarize recent findings on the functions of PHLPP in inflammatory and regulatory signaling in the context of both innate and adaptive immunity.


Assuntos
Isoenzimas , Proteínas Proto-Oncogênicas c-akt , Magnésio , Manganês , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Fosfoproteínas Fosfatases/genética , Fosfoproteínas Fosfatases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptor 4 Toll-Like
14.
Biochemistry ; 61(20): 2229-2240, 2022 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-36197914

RESUMO

α-Carboxyketose synthases, including 3-deoxy-d-arabinoheptulosonate 7-phosphate synthase (DAHPS), are long-standing targets for inhibition. They are challenging targets to create tight-binding inhibitors against, and inhibitors often display half-of-sites binding and partial inhibition. Half-of-sites inhibition demonstrates the existence of inter-subunit communication in DAHPS. We used X-ray crystallography and spatially resolved hydrogen-deuterium exchange (HDX) to reveal the structural and dynamic bases for inter-subunit communication in Escherichia coli DAHPS(Phe), the isozyme that is feedback-inhibited by phenylalanine. Crystal structures of this homotetrameric (dimer-of-dimers) enzyme are invariant over 91% of its sequence. Three variable loops make up 8% of the sequence and are all involved in inter-subunit contacts across the tight-dimer interface. The structures have pseudo-twofold symmetry indicative of inter-subunit communication across the loose-dimer interface, with the diagonal subunits B and C always having the same conformation as each other, while subunits A and D are variable. Spatially resolved HDX reveals contrasting responses to ligand binding, which, in turn, affect binding of the second substrate, erythrose-4-phosphate (E4P). The N-terminal peptide, M1-E12, and the active site loop that binds E4P, F95-K105, are key parts of the communication network. Inter-subunit communication appears to have a catalytic role in all α-carboxyketose synthase families and a regulatory role in some members.


Assuntos
3-Desoxi-7-Fosfo-Heptulonato Sintase , Isoenzimas , 3-Desoxi-7-Fosfo-Heptulonato Sintase/química , Sítios de Ligação , Catálise , Comunicação , Cristalografia por Raios X , Deutério , Escherichia coli , Humanos , Isoenzimas/metabolismo , Ligantes , Fenilalanina/metabolismo , Fosfatos
15.
Int J Mol Sci ; 23(19)2022 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-36233076

RESUMO

HDAC8 is an important target in several indication areas including childhood neuroblastoma. Several isozyme selective inhibitors of HDAC8 with L-shaped structures have been developed. A theoretical study has suggested that methionine 274 (M274) would act as a "switch" that controls a transient binding pocket, which is induced upon binding of L-shaped inhibitors. This hypothesis was experimentally examined in this study. The thermostability and functionality of HDAC8 wildtype and mutant variants with exchanged M274 were analyzed using biophysical methods. Furthermore, the binding kinetics of L-shaped and linear reference inhibitors of these HDAC8 variants were determined in order to elucidate the mode of interaction. Exchange of M274 has considerable impact on enzyme activity, but is not the decisive factor for selective recognition of HDAC8 by L-shaped inhibitors.


Assuntos
Inibidores de Histona Desacetilases , Neuroblastoma , Inibidores de Histona Desacetilases/química , Histona Desacetilases/metabolismo , Humanos , Isoenzimas , Metionina , Proteínas Repressoras
16.
Int J Mol Sci ; 23(19)2022 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-36233169

RESUMO

The Na,K-ATPase plays an important role in adaptation to hypoxia. Prolonged hypoxia results in loss of skeletal muscle mass, structure, and performance. However, hypoxic preconditioning is known to protect against a variety of functional impairments. In this study, we tested the possibility of mild hypoxia to modulate the Na,K-ATPase and to improve skeletal muscle electrogenesis. The rats were subjected to simulated high-altitude (3000 m above sea level) hypobaric hypoxia (HH) for 3 h using a hypobaric chamber. Isolated diaphragm and soleus muscles were tested. In the diaphragm muscle, HH increased the α2 Na,K-ATPase isozyme electrogenic activity and stably hyperpolarized the extrajunctional membrane for 24 h. These changes were accompanied by a steady increase in the production of thiobarbituric acid reactive substances as well as a decrease in the serum level of endogenous ouabain, a specific ligand of the Na,K-ATPase. HH also increased the α2 Na,K-ATPase membrane abundance without changing its total protein content; the plasma membrane lipid-ordered phase did not change. In the soleus muscle, HH protected against disuse (hindlimb suspension) induced sarcolemmal depolarization. Considering that the Na,K-ATPase is critical for maintaining skeletal muscle electrogenesis and performance, these findings may have implications for countermeasures in disuse-induced pathology and hypoxic therapy.


Assuntos
Ouabaína , ATPase Trocadora de Sódio-Potássio , Animais , Hipóxia/metabolismo , Isoenzimas/metabolismo , Ligantes , Lipídeos , Músculo Esquelético/metabolismo , Ouabaína/metabolismo , Ouabaína/farmacologia , Ratos , ATPase Trocadora de Sódio-Potássio/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
17.
Molecules ; 27(19)2022 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-36235158

RESUMO

The control of the duration of the dormancy phase is a significant challenge in the potato industry and for seed producers. However, the proteome landscape involved in the regulation of the length of the dormancy period over potato cultivars remains largely unexplored. In this study, we performed for the first time a comparative proteome profiling of potato cultivars with differential duration of tuber dormancy. More specifically, the proteome profiling of Agata, Kennebec and Agria commercial potato varieties with short, medium and medium-long dormancy, respectively, was assessed at the endodormancy stage using high-resolution two-dimensional electrophoresis (2-DE) coupled to reversed-phase liquid chromatography-tandem mass spectrometry (LC-TripleTOF MS/MS). A total of 11 proteins/isoforms with statistically significant differential abundance among cultivars were detected on 2-DE gels and confidently identified by LC-TripleTOF MS/MS. Identified proteins have known functions related to tuber development, sprouting and the oxylipins biosynthesis pathway. Fructokinase, a mitochondrial ADP/ATP carrier, catalase isozyme 2 and heat shock 70 kDa were the proteins with the strongest response to dormancy variations. To the best of our knowledge, this study reports the first candidate proteins underlying variable dormancy length in potato cultivars.


Assuntos
Solanum tuberosum , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Catalase/metabolismo , Frutoquinases/análise , Frutoquinases/metabolismo , Isoenzimas/metabolismo , Oxilipinas/metabolismo , Proteínas de Plantas/metabolismo , Tubérculos/química , Proteoma/metabolismo , Proteômica/métodos , Solanum tuberosum/química , Espectrometria de Massas em Tandem
18.
Molecules ; 27(20)2022 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-36296373

RESUMO

Human serum paraoxonase-1 (PON1) is an important hydrolase-type enzyme found in numerous tissues. Notably, it can exist in two isozyme-forms, Q and R, that exhibit different activities. This study presents an in silico (QSAR, Docking, MD and QM/MM) study of a set of compounds on the activity towards the PON1 isoenzymes (QPON1 and RPON1). Different rates of reaction for the Q and R isoenzymes were analyzed by modelling the effect of Q192R mutation on active sites. It was concluded that the Q192R mutation is not even close to the active site, while it is still changing the geometry of it. Using the combined genetic algorithm with multiple linear regression (GA-MLR) technique, several QSAR models were developed and relative activity rates of the isozymes of PON1 explained. From these, two QSAR models were selected, one each for the QPON1 and RPON1. Best selected models are four-variable MLR models for both Q and R isozymes with squared correlation coefficient R2 values of 0.87 and 0.83, respectively. In addition, the applicability domain of the models was analyzed based on the Williams plot. The results were discussed in the light of the main factors that influence the hydrolysis activity of the PON1 isozymes.


Assuntos
Arildialquilfosfatase , Isoenzimas , Humanos , Arildialquilfosfatase/genética , Hidrólise , Isoenzimas/genética , Modelos Lineares , Análise Multivariada
19.
Genes (Basel) ; 13(10)2022 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-36292720

RESUMO

Lactate dehydrogenase (LDH) catalyzes the reversible conversion of L-lactate to pyruvate. LDH-A deficiency is an autosomal recessive disorder (glycogenosis type XI, OMIM#612933) caused by mutations in the LDHA gene. We present two young adult female patients presenting with intolerance to anaerobic exercise, episodes of rhabdomyolysis, and, in one of the patients, psoriasis-like dermatitis. We identified in the LDHA gene a homozygous c.410C>A substitution that predicts a p.Ser137Ter nonsense mutation in Patient One and a compound heterozygous c.410C>A (p.Ser137Ter) and c.750G>A (p.Trp250Ter) nonsense mutation in Patient Two. The pathogenicity of the variants was demonstrated by electrophoretic separation of LDH isoenzymes. Moreover, a flat lactate curve on the forearm exercise test, along with the clinical combination of myopathy and psoriatic-like dermatitis, can also lead to the diagnosis.


Assuntos
Dermatite , Doença de Depósito de Glicogênio , Humanos , Feminino , Lactato Desidrogenase 5 , Isoenzimas/genética , Isoenzimas/metabolismo , Códon sem Sentido , Ácido Láctico/metabolismo , Ácido Pirúvico , Mutação
20.
Genome ; 65(12): 585-604, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36223652

RESUMO

Speciation by polyploidization has been documented to have independently occurred in 12 families of anuran amphibians. Tomopterna tandyi was described as a South African allotetraploid species of sand frogs in the family Pyxicephalidae. Recent taxonomic revisions and new species descriptions in the genus present problems with respect to the evolution of this tetraploid species. Chromosomes, mitochondrial and nuclear gene sequences, isozymes, and male mating calls were examined for T. tandyi and for diploid species of Tomopterna. Mitochondrial sequences confirmed the diploid species, T. adiastola, to be the maternal ancestor that gave rise to the tetraploid about 5 mya. Nuclear sequences and isozymes reveal a complex reticulation of paternal ancestry that may be explained by occasional hybridization of T. tandyi with diploid species of Tompoterna at various times in sympatric populations. Interspecific diploid to tetraploid gene introgression is suspected to have also occurred in Australian and North American tetraploid species of frogs. Diploid to tetraploid introgression is facilitated through triploid hybrids that are more viable than diploid hybrids and produce unreduced triploid eggs.


Assuntos
Tetraploidia , Triploidia , Animais , Masculino , Isoenzimas/genética , Austrália , Anuros/genética , Diploide , Cromossomos , Poliploidia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...