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1.
Int J Mol Sci ; 22(17)2021 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-34502454

RESUMO

COVID-19 is a global threat that has spread since the end of 2019, causing severe clinical sequelae and deaths, in the context of a world pandemic. The infection of the highly pathogenetic and infectious SARS-CoV-2 coronavirus has been proven to exert systemic effects impacting the metabolism. Yet, the metabolic pathways involved in the pathophysiology and progression of COVID-19 are still unclear. Here, we present the results of a mass spectrometry-based targeted metabolomic analysis on a cohort of 52 hospitalized COVID-19 patients, classified according to disease severity as mild, moderate, and severe. Our analysis defines a clear signature of COVID-19 that includes increased serum levels of lactic acid in all the forms of the disease. Pathway analysis revealed dysregulation of energy production and amino acid metabolism. Globally, the variations found in the serum metabolome of COVID-19 patients may reflect a more complex systemic perturbation induced by SARS-CoV-2, possibly affecting carbon and nitrogen liver metabolism.


Assuntos
Biomarcadores/sangue , Carbono/metabolismo , Fígado/metabolismo , Metaboloma , Nitrogênio/metabolismo , Aminoácidos/metabolismo , COVID-19/sangue , COVID-19/patologia , COVID-19/virologia , Citocinas/sangue , Análise Discriminante , Humanos , Análise dos Mínimos Quadrados , Redes e Vias Metabólicas/genética , Metabolômica/métodos , SARS-CoV-2/isolamento & purificação , Índice de Gravidade de Doença
2.
Biochem Biophys Res Commun ; 574: 14-19, 2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-34425281

RESUMO

Following the initial surges of the Alpha (B.1.1.7) and the Beta (B.1.351) variants, a more infectious Delta variant (B.1.617.2) is now surging, further deepening the health crises caused by the pandemic. The sharp rise in cases attributed to the Delta variant has made it especially disturbing and is a variant of concern. Fortunately, current vaccines offer protection against known variants of concern, including the Delta variant. However, the Delta variant has exhibited some ability to dodge the immune system as it is found that neutralizing antibodies from prior infections or vaccines are less receptive to binding with the Delta spike protein. Here, we investigated the structural changes caused by the mutations in the Delta variant's receptor-binding interface and explored the effects on binding with the ACE2 receptor as well as with neutralizing antibodies. We find that the receptor-binding ß-loop-ß motif adopts an altered but stable conformation causing separation in some of the antibody binding epitopes. Our study shows reduced binding of neutralizing antibodies and provides a possible mechanism for the immune evasion exhibited by the Delta variant.


Assuntos
Enzima de Conversão de Angiotensina 2/imunologia , COVID-19/imunologia , Evasão da Resposta Imune/imunologia , Mutação/imunologia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Aminoácidos/genética , Aminoácidos/imunologia , Aminoácidos/metabolismo , Enzima de Conversão de Angiotensina 2/genética , Enzima de Conversão de Angiotensina 2/metabolismo , Anticorpos Antivirais/imunologia , Sítios de Ligação/genética , Sítios de Ligação/imunologia , COVID-19/metabolismo , COVID-19/virologia , Humanos , Evasão da Resposta Imune/genética , Simulação de Dinâmica Molecular , Mutação/genética , Testes de Neutralização , Ligação Proteica , Domínios Proteicos , SARS-CoV-2/genética , SARS-CoV-2/metabolismo , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética
3.
BMC Plant Biol ; 21(1): 373, 2021 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-34388969

RESUMO

BACKGROUND: Flowering is an important inflection point in the transformation from vegetative to reproductive growth, and premature bolting severely decreases crop yield and quality. RESULTS: In this study, a stable early-bolting mutant, ebm3, was identified in an ethyl methanesulfonate (EMS)-mutagenized population of a Chinese cabbage doubled haploid (DH) line 'FT'. Compared with 'FT', ebm3 showed early bolting under natural cultivation in autumn, and curled leaves. Genetic analysis showed that the early-bolting phenotype was controlled by a single recessive nuclear gene. Modified MutMap sequencing, genotyping analyses and allelism test provide strong evidence that BrEBM3 (BraA04g017190.3 C), encoding the histone methyltransferase CURLY LEAF (CLF), was the strongly candidate gene of the emb3. A C to T base substitution in the 14th exon of BrEBM3 resulted in an amino acid change (S to F) and the early-bolting phenotype of emb3. The mutation occurred in the SET domain (Suppressor of protein-effect variegation 3-9, Enhancer-of-zeste, Trithorax), which catalyzes site- and state-specific lysine methylation in histones. Tissue-specific expression analysis showed that BrEBM3 was highly expressed in the flower and bud. Promoter activity assay confirmed that BrEBM3 promoter was active in inflorescences. Subcellular localization analysis revealed that BrEBM3 localized in the nucleus. Transcriptomic studies supported that BrEBM3 mutation might repress H3K27me3 deposition and activate expression of the AGAMOUS (AG) and AGAMOUS-like (AGL) loci, resulting in early flowering. CONCLUSIONS: Our study revealed that an EMS-induced early-bolting mutant ebm3 in Chinese cabbage was caused by a nonsynonymous mutation in BraA04g017190.3 C, encoding the histone methyltransferase CLF. These results improve our knowledge of the genetic and genomic resources of bolting and flowering, and may be beneficial to the genetic improvement of Chinese cabbage.


Assuntos
Substituição de Aminoácidos , Brassica rapa/enzimologia , Histona Metiltransferases/metabolismo , Proteínas de Plantas/metabolismo , Aminoácidos/metabolismo , Brassica rapa/genética , Brassica rapa/crescimento & desenvolvimento , Flores/enzimologia , Flores/genética , Flores/crescimento & desenvolvimento , Histona Metiltransferases/química , Histona Metiltransferases/genética , Mutação , Proteínas de Plantas/genética , Transcriptoma
4.
Mol Cell ; 81(16): 3310-3322.e6, 2021 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-34416138

RESUMO

Amino acid starvation is sensed by Escherichia coli RelA and Bacillus subtilis Rel through monitoring the aminoacylation status of ribosomal A-site tRNA. These enzymes are positively regulated by their product-the alarmone nucleotide (p)ppGpp-through an unknown mechanism. The (p)ppGpp-synthetic activity of Rel/RelA is controlled via auto-inhibition by the hydrolase/pseudo-hydrolase (HD/pseudo-HD) domain within the enzymatic N-terminal domain region (NTD). We localize the allosteric pppGpp site to the interface between the SYNTH and pseudo-HD/HD domains, with the alarmone stimulating Rel/RelA by exploiting intra-NTD autoinhibition dynamics. We show that without stimulation by pppGpp, starved ribosomes cannot efficiently activate Rel/RelA. Compromised activation by pppGpp ablates Rel/RelA function in vivo, suggesting that regulation by the second messenger (p)ppGpp is necessary for mounting an acute starvation response via coordinated enzymatic activity of individual Rel/RelA molecules. Control by (p)ppGpp is lacking in the E. coli (p)ppGpp synthetase SpoT, thus explaining its weak synthetase activity.


Assuntos
Regulação Alostérica/genética , Proteínas de Escherichia coli/genética , GTP Pirofosfoquinase/genética , Guanosina Pentafosfato/genética , Pirofosfatases/genética , Aminoácidos/metabolismo , Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Domínio Catalítico/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Hidrolases/genética , Ribossomos/genética , Ribossomos/metabolismo , Inanição/genética , Inanição/metabolismo
5.
Int J Mol Sci ; 22(15)2021 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-34360577

RESUMO

Cytochrome P450 monooxygenase CYP51 (sterol 14α-demethylase) is a well-known target of the azole drug fluconazole for treating cryptococcosis, a life-threatening fungal infection in immune-compromised patients in poor countries. Studies indicate that mutations in CYP51 confer fluconazole resistance on cryptococcal species. Despite the importance of CYP51 in these species, few studies on the structural analysis of CYP51 and its interactions with different azole drugs have been reported. We therefore performed in silico structural analysis of 11 CYP51s from cryptococcal species and other Tremellomycetes. Interactions of 11 CYP51s with nine ligands (three substrates and six azoles) performed by Rosetta docking using 10,000 combinations for each of the CYP51-ligand complex (11 CYP51s × 9 ligands = 99 complexes) and hierarchical agglomerative clustering were used for selecting the complexes. A web application for visualization of CYP51s' interactions with ligands was developed (http://bioshell.pl/azoledocking/). The study results indicated that Tremellomycetes CYP51s have a high preference for itraconazole, corroborating the in vitro effectiveness of itraconazole compared to fluconazole. Amino acids interacting with different ligands were found to be conserved across CYP51s, indicating that the procedure employed in this study is accurate and can be automated for studying P450-ligand interactions to cater for the growing number of P450s.


Assuntos
Aminoácidos/metabolismo , Azóis/metabolismo , Basidiomycota/enzimologia , Sistema Enzimático do Citocromo P-450/metabolismo , Fluconazol/metabolismo , Proteínas Fúngicas/metabolismo , Itraconazol/metabolismo , Aminoácidos/química , Antifúngicos/química , Antifúngicos/metabolismo , Azóis/química , Simulação por Computador , Sistema Enzimático do Citocromo P-450/química , Fluconazol/química , Proteínas Fúngicas/química , Itraconazol/química , Ligantes , Modelos Moleculares , Filogenia , Ligação Proteica , Conformação Proteica , Especificidade por Substrato
6.
Nat Commun ; 12(1): 4905, 2021 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-34385458

RESUMO

α-ketoglutarate (KG), also referred to as 2-oxoglutarate, is a key intermediate of cellular metabolism with pleiotropic functions. Cell-permeable esterified analogs are widely used to study how KG fuels bioenergetic and amino acid metabolism and DNA, RNA, and protein hydroxylation reactions, as cellular membranes are thought to be impermeable to KG. Here we show that esterified KG analogs rapidly hydrolyze in aqueous media, yielding KG that, in contrast to prevailing assumptions, imports into many cell lines. Esterified KG analogs exhibit spurious KG-independent effects on cellular metabolism, including extracellular acidification, arising from rapid hydrolysis and de-protonation of α-ketoesters, and significant analog-specific inhibitory effects on glycolysis or mitochondrial respiration. We observe that imported KG decarboxylates to succinate in the cytosol and contributes minimally to mitochondrial metabolism in many cell lines cultured in normal conditions. These findings demonstrate that nuclear and cytosolic KG-dependent reactions may derive KG from functionally distinct subcellular pools and sources.


Assuntos
Aminoácidos/metabolismo , Metabolismo Energético , Ésteres/metabolismo , Ácidos Cetoglutáricos/metabolismo , Mitocôndrias/metabolismo , Ácido Succínico/metabolismo , Animais , Linhagem Celular Tumoral , Citosol/metabolismo , Ésteres/química , Glicólise , Células HEK293 , Humanos , Hidrólise , Interações Hidrofóbicas e Hidrofílicas , Ácidos Cetoglutáricos/química , Camundongos , Consumo de Oxigênio , Células RAW 264.7
7.
Nat Commun ; 12(1): 4932, 2021 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-34389733

RESUMO

BAX is a pro-apoptotic member of the BCL-2 family, which regulates the balance between cellular life and death. During homeostasis, BAX predominantly resides in the cytosol as a latent monomer but, in response to stress, transforms into an oligomeric protein that permeabilizes the mitochondria, leading to apoptosis. Because renegade BAX activation poses a grave risk to the cell, the architecture of BAX must ensure monomeric stability yet enable conformational change upon stress signaling. The specific structural features that afford both stability and dynamic flexibility remain ill-defined and represent a critical control point of BAX regulation. We identify a nexus of interactions involving four residues of the BAX core α5 helix that are individually essential to maintaining the structure and latency of monomeric BAX and are collectively required for dimeric assembly. The dual yet distinct roles of these residues reveals the intricacy of BAX conformational regulation and opportunities for therapeutic modulation.


Assuntos
Aminoácidos/genética , Apoptose/genética , Mutação , Transdução de Sinais/genética , Proteína X Associada a bcl-2/genética , Aminoácidos/química , Aminoácidos/metabolismo , Animais , Sítios de Ligação/genética , Células Cultivadas , Citosol/metabolismo , Humanos , Camundongos Knockout , Mitocôndrias/metabolismo , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Multimerização Proteica , Proteína X Associada a bcl-2/química , Proteína X Associada a bcl-2/metabolismo
8.
NPJ Biofilms Microbiomes ; 7(1): 57, 2021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-34230496

RESUMO

Bacterial vaginosis (BV) is a gynecologic disorder characterized by a shift in cervicovaginal microbiota from Lactobacillus spp. dominance to a polymicrobial biofilm composed of diverse anaerobes. We utilized a well-characterized human three-dimensional cervical epithelial cell model in conjunction with untargeted metabolomics and immunoproteomics analyses to determine the immunometabolic contribution of three members of the Veillonellaceae family: Veillonella atypica, Veillonella montpellierensis and Megasphaera micronuciformis at this site. We found that Veillonella spp. infections induced significant elevation of polyamines. M. micronuciformis infections significantly increased soluble inflammatory mediators, induced moderate levels of cell cytotoxicity, and accumulation of cell membrane lipids relative to Veillonella spp. Notably, both V. atypica and V. montpellierensis infections resulted in consumption of lactate, a key metabolite linked to gynecologic and reproductive health. Collectively our approach and data provide unique insights into the specific contributions of Veillonellaceae members to the pathogenesis of BV and women's health.


Assuntos
Metabolismo Energético , Membrana Mucosa/metabolismo , Membrana Mucosa/microbiologia , Vagina/metabolismo , Vagina/microbiologia , Veillonellaceae/fisiologia , Aminoácidos/metabolismo , Técnicas de Cultura de Células , Biologia Computacional/métodos , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Células Epiteliais/ultraestrutura , Feminino , Interações Hospedeiro-Patógeno/imunologia , Humanos , Metabolismo dos Lipídeos , Metaboloma , Metabolômica/métodos , Vaginose Bacteriana/metabolismo , Vaginose Bacteriana/microbiologia
9.
FEBS Lett ; 595(16): 2085-2098, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34197627

RESUMO

Brown and beige adipocytes dissipate energy by uncoupling protein 1 (UCP1)-dependent and UCP1-independent thermogenesis, which may be utilized to develop treatments against obesity. We have found that mRNA and protein expression of the alanine/serine/cysteine transporter-1 (ASC-1) was induced during adipocyte differentiation of human brown-prone deep neck and beige-competent subcutaneous neck progenitors, and SGBS preadipocytes. cAMP stimulation of differentiated adipocytes led to elevated uptake of serine, cysteine, and glycine, in parallel with increased oxygen consumption, augmented UCP1-dependent proton leak, increased creatine-driven substrate cycle-coupled respiration, and upregulation of thermogenesis marker genes and several respiratory complex subunits; these outcomes were impeded in the presence of the specific ASC-1 inhibitor, BMS-466442. Our data suggest that ASC-1-dependent consumption of serine, cysteine, and glycine is required for efficient thermogenic stimulation of human adipocytes.


Assuntos
Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Adrenérgicos/farmacologia , Sistema y+ de Transporte de Aminoácidos/metabolismo , Aminoácidos/metabolismo , Termogênese , Transporte Biológico/efeitos dos fármacos , Humanos , Termogênese/efeitos dos fármacos
11.
Fish Physiol Biochem ; 47(4): 1243-1255, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34226986

RESUMO

The effects of stocking density on growth performance, serum biochemistry, digestive enzymes, immune response, and muscle quality of largemouth bass (Micropterus salmoides) reared in nine in-pond raceway systems (IPRS, 22.0 m × 5.0 m × 2.0 m) were studied. M. salmoides with initial an body weight of 8.25 ± 0.51 g and body length of 6.99 ± 0.44 cm were reared at an initial stocking density of 90.91 ind./m3 (low stocking density, LSD), 113.63 ind./m3 (middle stocking density, MSD), and 136.36 ind./m3 (high stocking density, HSD) with triplication. After 300 days of culture, MSD recorded the highest final body weight, weight gain, specific growth rate, and yield, but the food conversion ratio in MSD was the lowest. The viscerosomatic index in LSD was significantly higher than other groups. The fish serum reared at HSD showed significantly lower total protein, higher total cholesterol, triglyceride, total bilirubin, glucose content, alanine transaminase, and aspartate transaminase activity. Significantly lower intestinal amylase, lipase, trypsin activities, hepatic superoxide dismutase (SOD) and catalase (CAT) activities, and higher malondialdehyde content were detected in HSD compared to others. The content of crude lipid, saturated fatty acid decreased, and total essential amino acid, delicious amino acid, and polyunsaturated fatty acid increased in muscle with stocking density increase. No significant difference was observed in muscle texture. Profitability analysis indicated the benefit-to-cost ratio varied between 1.10 and 1.68, of which MSD was significantly higher than others. The optimal stocking density for M. salmoides should be 113.63 ind./m3 in an IPRS farm.


Assuntos
Aquicultura/métodos , Bass , Alanina Transaminase/sangue , Aminoácidos/metabolismo , Amilases/metabolismo , Animais , Aspartato Aminotransferases/sangue , Bass/sangue , Bass/crescimento & desenvolvimento , Bass/imunologia , Bass/metabolismo , Catalase/metabolismo , Ácidos Graxos/metabolismo , Proteínas de Peixes/sangue , Imunidade , Intestinos/enzimologia , Lipase/metabolismo , Fígado/metabolismo , Músculos/química , Esteróis/sangue , Superóxido Dismutase/metabolismo , Triglicerídeos/sangue , Tripsina/metabolismo
12.
J Plant Physiol ; 264: 153470, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34274841

RESUMO

After an episode of heat stress plants retain a cellular "memory" of this event, a phenomenon known as thermomemory. This mechanism allows plants to better cope against a subsequent heat event. Thermomemory occurs through the persistence of heat shock proteins (HSPs) synthesized after the first "priming" event. Maintenance of this thermomemory comes at the cost to growth though, therefore it is vital that the memory is reset when no longer required. Recently, it has been reported that autophagy is important for resetting the thermomemory. It has also been shown recently that in response to heat, Arabidopsis displays an increase in chloroplast free calcium concentration which is partially dependent on calcium sensing receptor (CAS) protein. It is not known what the purpose of this heat-activated calcium signal is. Therefore, we compared downstream responses to heat in wild type (WT) and cas mutants, as the latter produce a reduced chloroplast calcium signal to heat. We found that after thermopriming the cas mutants displayed a greater biomass and a reduced level of the small heat shock protein HSP 17.6 degradation compared to WT. cas mutants did not show an increase in free amino acid levels after thermopriming, suggesting reduced autophagy. These results suggest that heat-induced chloroplast calcium elevation is a positive signal for resetting of the thermomemory.


Assuntos
Cálcio/metabolismo , Cloroplastos/metabolismo , Transdução de Sinais , Aminoácidos/metabolismo , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Choque Térmico/metabolismo , Resposta ao Choque Térmico
13.
Chem Biol Interact ; 347: 109602, 2021 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-34331906

RESUMO

Breast cancer is the most common cancer among females and the leading cause of cancer-related deaths. Approximately 70 % of breast cancers are estrogen receptor (ER) positive. An ER antagonist such as tamoxifen is used as adjuvant therapy in ER-positive patients. The major problem with endocrine therapy is the emergence of acquired resistance in approximately 40 % of patients receiving tamoxifen. Metabolic alteration is one of the hallmarks of cancer cells. Rapidly proliferating cancer cells require increased nutritional support to fuel various functions such as proliferation, cell migration, and metastasis. Recent studies have established that the metabolic state of cancer cells influences their susceptibility to chemotherapeutic drugs and that cancer cells reprogram their metabolism to develop into resistant phenotypes. In this review, we discuss the major findings on metabolic pathway alterations in tamoxifen-resistant (TAMR) breast cancer and the molecular mechanisms known to regulate the expression and function of metabolic enzymes and the respective metabolite levels upon tamoxifen treatment. It is anticipated that this in-depth analysis of specific metabolic pathways in TAMR cancer might be exploited therapeutically.


Assuntos
Neoplasias da Mama/metabolismo , Resistencia a Medicamentos Antineoplásicos/fisiologia , Tamoxifeno/uso terapêutico , Aminoácidos/metabolismo , Animais , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Metabolismo Energético/fisiologia , Regulação Neoplásica da Expressão Gênica/fisiologia , Humanos , Metabolismo dos Lipídeos/fisiologia , Ácidos Nucleicos/metabolismo
14.
Chem Pharm Bull (Tokyo) ; 69(7): 652-660, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34193714

RESUMO

The hydrocarbon-chain packing structure of intercellular lipids in the stratum corneum (SC) is critical to the skin's barrier function. We previously found that formation of V-shaped ceramide reduces the barrier function of skin. There are few agents, apart from ceramides and fatty acids that can improve the orthorhombic packing (Orth) ratio of the intercellular lipid packing structure. In this study, we investigated agents that directly increase the Orth ratio. We selected an intercellular lipid model consisting of ceramide, cholesterol, and palmitic acid and performed differential scanning calorimetry. We focused on natural moisturizing factor components in the SC, and therefore investigated amino acids and their derivatives. The results of our intercellular lipid model-based study indicate that N-acetyl-L-hydroxyproline (AHYP), remarkably, maintains the lamellar structure. We verified the effect of AHYP on the lamellar structure and hydrocarbon chain packing structure of intercellular lipids using time-resolved X-ray diffraction measurements of human SC. We also determined the direct physicochemical effects of AHYP on the Orth ratio of the hydrocarbon-chain packing structure. Hence, the results of our human SC study suggest that AHYP preserves skin barrier function by maintaining the hydrocarbon-chain packing structure of intercellular lipids via electrostatic repulsion. These findings will facilitate the development of skincare formulation that can maintain the skin's barrier function.


Assuntos
Aminoácidos/metabolismo , Absorção Cutânea , Acetilação , Aminoácidos/química , Varredura Diferencial de Calorimetria , Colesterol/química , Epiderme/química , Humanos , Hidroxiprolina/química , Hidroxiprolina/metabolismo , Bicamadas Lipídicas/química , Bicamadas Lipídicas/metabolismo , Nanoestruturas/química , Ácido Palmítico/química , Espalhamento a Baixo Ângulo , Difração de Raios X
15.
J Chem Phys ; 154(19): 195101, 2021 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-34240918

RESUMO

Interactions in enzymes between catalytic and neighboring amino acids and how these interactions facilitate catalysis are examined. In examples from both natural and designed enzymes, it is shown that increases in catalytic rates may be achieved through elongation of the buffer range of the catalytic residues; such perturbations in the protonation equilibria are, in turn, achieved through enhanced coupling of the protonation equilibria of the active ionizable residues with those of other ionizable residues. The strongest coupling between protonation states for a pair of residues that deprotonate to form an anion (or a pair that accept a proton to form a cation) is achieved when the difference in the intrinsic pKas of the two residues is approximately within 1 pH unit. Thus, catalytic aspartates and glutamates are often coupled to nearby acidic residues. For an anion-forming residue coupled to a cation-forming residue, the elongated buffer range is achieved when the intrinsic pKa of the anion-forming residue is higher than the intrinsic pKa of the (conjugate acid of the) cation-forming residue. Therefore, the high pKa, anion-forming residues tyrosine and cysteine make good coupling partners for catalytic lysine residues. For the anion-cation pairs, the optimum difference in intrinsic pKas is a function of the energy of interaction between the residues. For the energy of interaction ε expressed in units of (ln 10)RT, the optimum difference in intrinsic pKas is within ∼1 pH unit of ε.


Assuntos
Aminoácidos/química , Glicosídeo Hidrolases/química , Aminoácidos/metabolismo , Biocatálise , Glicosídeo Hidrolases/metabolismo , Concentração de Íons de Hidrogênio , Eletricidade Estática
16.
Nutrients ; 13(6)2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34204378

RESUMO

In patients with phenylketonuria (PKU), treated by diet therapy only, evidence suggests that areal bone mineral density (BMDa) is within the normal clinical reference range but is below the population norm. AIMS: To study longitudinal bone density, mass, and geometry over 36 months in children with PKU taking either amino acid (L-AA) or casein glycomacropeptide substitutes (CGMP-AA) as their main protein source. METHODOLOGY: A total of 48 subjects completed the study, 19 subjects in the L-AA group (median age 11.1, range 5-16 years) and 29 subjects in the CGMP-AA group (median age 8.3, range 5-16 years). The CGMP-AA was further divided into two groups, CGMP100 (median age 9.2, range 5-16 years) (n = 13), children taking CGMP-AA only and CGMP50 (median age 7.3, range 5-15 years) (n = 16), children taking a combination of CGMP-AA and L-AA. Dual X-ray absorptiometry (DXA) was measured at enrolment and 36 months, peripheral quantitative computer tomography (pQCT) at 36 months only, and serum blood and urine bone turnover markers (BTM) and blood bone biochemistry at enrolment, 6, 12, and 36 months. RESULTS: No statistically significant differences were found between the three groups for DXA outcome parameters, i.e., BMDa (L2-L4 BMDa g/cm2), bone mineral apparent density (L2-L4 BMAD g/cm3) and total body less head BMDa (TBLH g/cm2). All blood biochemistry markers were within the reference ranges, and BTM showed active bone turnover with a trend for BTM to decrease with increasing age. CONCLUSIONS: Bone density was clinically normal, although the median z scores were below the population mean. BTM showed active bone turnover and blood biochemistry was within the reference ranges. There appeared to be no advantage to bone density, mass, or geometry from taking a macropeptide-based protein substitute as compared with L-AAs.


Assuntos
Absorciometria de Fóton , Aminoácidos/metabolismo , Densidade Óssea/genética , Densidade Óssea/fisiologia , Remodelação Óssea , Caseínas/metabolismo , Fragmentos de Peptídeos/metabolismo , Fenilcetonúrias/dietoterapia , Adolescente , Antropometria , Biomarcadores/sangue , Biomarcadores/urina , Criança , Pré-Escolar , Feminino , Humanos , Estudos Longitudinais , Masculino , Osteoporose , Fenilcetonúrias/sangue , Fenilcetonúrias/urina
17.
Molecules ; 26(11)2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34200149

RESUMO

We compared the efficacy for protein extraction of water versus enzymatic extraction. The amino-acid composition, inhibitory activity against enzymes α-amylase and α-glucosidase, and anti-glycation activities of silk protein extract (SPE) were determined. We used water extraction (100 °C, six hours) and protease-enzymatic extraction. The microstructure of silk fibers was obviously different after extraction. The results showed that enzymatic extraction gave the greater values of protein content, amino acids, total phenolic content (TPC), and total flavonoid content (TFC), as well as all biological activities parameters tested, but it also provided a more bitter taste in the extract-contributing amino acids of 51% (arginine, phenylalanine, histidine, valine, tryptophan, isoleucine, and leucine) and less sweet and umami taste contributing amino acids than did water extraction, which could be more suitable to be used as concentrated nutraceuticals.


Assuntos
Aminoácidos/química , Aminoácidos/metabolismo , Enzimas/química , Seda/química , Seda/metabolismo , Água/química , Flavonoides/química , Fenol/química , Proteínas/metabolismo
18.
Int J Mol Sci ; 22(12)2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34203772

RESUMO

Protein-protein interactions (PPIs) are the basis of most biological functions determined by residue-residue interactions (RRIs). Predicting residue pairs responsible for the interaction is crucial for understanding the cause of a disease and drug design. Computational approaches that considered inexpensive and faster solutions for RRI prediction have been widely used to predict protein interfaces for further analysis. This study presents RRI-Meta, an ensemble meta-learning-based method for RRI prediction. Its hierarchical learning structure comprises four base classifiers and one meta-classifier to integrate predictive strengths from different classifiers. It considers multiple feature types, including sequence-, structure-, and neighbor-based features, for characterizing other properties of a residue interaction environment to better distinguish between noninteracting and interacting residues. We conducted the same experiments using the same data as previously reported in the literature to demonstrate RRI-Meta's performance. Experimental results show that RRI-Meta is superior to several current prediction tools. Additionally, to analyze the factors that affect the performance of RRI-Meta, we conducted a comparative case study using different protein complexes.


Assuntos
Algoritmos , Aminoácidos/metabolismo , Biologia Computacional/métodos , Área Sob a Curva , Modelos Moleculares , Curva ROC
19.
Int J Mol Sci ; 22(13)2021 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-34206906

RESUMO

Leishmania survival inside macrophages depends on factors that lead to the immune response evasion during the infection. In this context, the metabolic scenario of the host cell-parasite relationship can be crucial to understanding how this parasite can survive inside host cells due to the host's metabolic pathways reprogramming. In this work, we aimed to analyze metabolic networks of bone marrow-derived macrophages from C57BL/6 mice infected with Leishmania amazonensis wild type (La-WT) or arginase knocked out (La-arg-), using the untargeted Capillary Electrophoresis-Mass Spectrometry (CE-MS) approach to assess metabolomic profile. Macrophages showed specific changes in metabolite abundance upon Leishmania infection, as well as in the absence of parasite-arginase. The absence of L. amazonensis-arginase promoted the regulation of both host and parasite urea cycle, glycine and serine metabolism, ammonia recycling, metabolism of arginine, proline, aspartate, glutamate, spermidine, spermine, methylhistidine, and glutathione metabolism. The increased L-arginine, L-citrulline, L-glutamine, oxidized glutathione, S-adenosylmethionine, N-acetylspermidine, trypanothione disulfide, and trypanothione levels were observed in La-WT-infected C57BL/6-macrophage compared to uninfected. The absence of parasite arginase increased L-arginine, argininic acid, and citrulline levels and reduced ornithine, putrescine, S-adenosylmethionine, glutamic acid, proline, N-glutamyl-alanine, glutamyl-arginine, trypanothione disulfide, and trypanothione when compared to La-WT infected macrophage. Moreover, the absence of parasite arginase leads to an increase in NO production levels and a higher infectivity rate at 4 h of infection. The data presented here show a host-dependent regulation of metabolomic profiles of C57BL/6 macrophages compared to the previously observed BALB/c macrophages infected with L. amazonensis, an important fact due to the dual and contrasting macrophage phenotypes of those mice. In addition, the Leishmania-arginase showed interference with the urea cycle, glycine, and glutathione metabolism during host-pathogen interactions.


Assuntos
Aminoácidos/metabolismo , Interações Hospedeiro-Parasita , Leishmaniose/metabolismo , Macrófagos/metabolismo , Metaboloma , Poliaminas/metabolismo , Animais , Arginase/metabolismo , Células Cultivadas , Leishmania/enzimologia , Leishmania/patogenicidade , Macrófagos/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Proteínas de Protozoários/metabolismo
20.
Biomed Pharmacother ; 139: 111663, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34243605

RESUMO

Isolongifolanone is a high value-added sustainable natural product. Recent studies have demonstrated that isolongifolanone possesses anticancer activities. In this study, a series of novel pyrazole ring-containing isolongifolanone derivatives was designed, synthesized, and their anti-proliferative activities in three cancer cell lines were evaluated. Among them, compound 3b exhibited strongest antiproliferative ability on MCF-7 cancer cells and induced the generation of intracellular ROS and mitochondrial depolarization. More importantly, compound 3b still maintained antitumor activity in MCF-7 3D culture systems. The study on molecular mechanism suggested that compound 3b induced apoptosis via activation of caspase-3 and PARP, also via decreasing of Bcl-2 and increasing of Bax and p53. Moreover, compound 3b down-regulated the level of CDK2, a crucial cyclin-dependent kinase which is necessary for the progression of the cells out of the G1 phase of the cell cycle. Docking results showed that compound 3b could bind well with CDK2 by forming hydrogen bonds with amino acid residues (LYS89 and HIS84). These results suggested that compound 3b could be taken as a lead compound for anticancer agents.


Assuntos
Antineoplásicos/farmacologia , Quinase 2 Dependente de Ciclina/metabolismo , Pirazóis/farmacologia , Sesquiterpenos/farmacologia , Células A549 , Aminoácidos/metabolismo , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Fase G1/efeitos dos fármacos , Células HeLa , Humanos , Células MCF-7 , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteína Supressora de Tumor p53/metabolismo
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