RESUMO
Glycoside hydrolase family 5 (GH5) encompasses enzymes with several different activities, including endo-1,4-ß-mannosidases. These enzymes are involved in mannan degradation, and have a number of biotechnological applications, such as mannooligosaccharide prebiotics production, stain removal and dyes decolorization, to name a few. Despite the importance of GH5 enzymes, only a few members of subfamily 7 were structurally characterized. In the present work, biochemical and structural characterization of Bacillus licheniformis GH5 mannanase, BlMan5_7 were performed and the enzyme cleavage pattern was analyzed, showing that BlMan5_7 requires at least 5 occupied subsites to perform efficient hydrolysis. Additionally, crystallographic structure at 1.3 Å resolution was determined and mannoheptaose (M7) was docked into the active site to investigate the interactions between substrate and enzyme through molecular dynamic (MD) simulations, revealing the existence of a - 4 subsite, which might explain the generation of mannotetraose (M4) as an enzyme product. Biotechnological application of the enzyme in stain removal was investigated, demonstrating that BlMan5_7 addition to washing solution greatly improves mannan-based stain elimination.
Assuntos
Bacillus licheniformis , Domínio Catalítico , Mutagênese Sítio-Dirigida , Bacillus licheniformis/enzimologia , Bacillus licheniformis/genética , Cristalografia por Raios X , Simulação de Dinâmica Molecular , Manosidases/química , Manosidases/genética , Manosidases/metabolismo , Especificidade por Substrato , Hidrólise , Tetroses/química , Tetroses/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Conformação Proteica , Mananas/química , Mananas/metabolismo , beta-Manosidase/química , beta-Manosidase/genética , beta-Manosidase/metabolismo , Modelos Moleculares , Simulação de Acoplamento Molecular , OligossacarídeosRESUMO
Leptospirosis is a bacterial disease that affects humans and animals and is caused by Leptospira. The recommended treatment for leptospirosis is antibiotic therapy, which should be given early in the course of the disease. Despite the use of these antibiotics, their role during the course of the disease is still not completely clear because of the lack of effective clinical trials, particularly for severe cases of the disease. Here, we present the characterization of L. interrogans Lsa45 protein by gel filtration, protein crystallography, SAXS, fluorescence and enzymatic assays. The oligomeric studies revealed that Lsa45 is monomeric in solution. The crystal structure of Lsa45 revealed the presence of two subdomains: a large α/ß subdomain and a small α-helical subdomain. The large subdomain contains the amino acids Ser122, Lys125, and Tyr217, which correspond to the catalytic triad that is essential for ß-lactamase or serine hydrolase activity in similar enzymes. Additionally, we also confirmed the bifunctional promiscuity of Lsa45, in hydrolyzing both the 4-nitrophenyl acetate (p-NPA) and nitrocefin ß-lactam antibiotic. Therefore, this study provides novel insights into the structure and function of enzymes from L. interrogans, which furthers our understanding of this bacterium and the development of new therapies for the prevention and treatment of leptospirosis.
RESUMO
Leptospirosis is a bacterial disease that affects humans and animals and is caused by Leptospira. The recommended treatment for leptospirosis is antibiotic therapy, which should be given early in the course of the disease. Despite the use of these antibiotics, their role during the course of the disease is still not completely clear because of the lack of effective clinical trials, particularly for severe cases of the disease. Here, we present the characterization of L. interrogans Lsa45 protein by gel filtration, protein crystallography, SAXS, fluorescence and enzymatic assays. The oligomeric studies revealed that Lsa45 is monomeric in solution. The crystal structure of Lsa45 revealed the presence of two subdomains: a large α/β subdomain and a small α-helical subdomain. The large subdomain contains the amino acids Ser122, Lys125, and Tyr217, which correspond to the catalytic triad that is essential for β-lactamase or serine hydrolase activity in similar enzymes. Additionally, we also confirmed the bifunctional promiscuity of Lsa45, in hydrolyzing both the 4-nitrophenyl acetate (p-NPA) and nitrocefin β-lactam antibiotic. Therefore, this study provides novel insights into the structure and function of enzymes from L. interrogans, which furthers our understanding of this bacterium and the development of new therapies for the prevention and treatment of leptospirosis.
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The risk of severe COVID-19 increases with age as older patients are at highest risk. Thus, there is an urgent need to identify how severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) interacts with blood components during aging. We investigated the whole blood transcriptome from the Genotype-Tissue Expression (GTEx) database to explore differentially expressed genes (DEGs) translated into proteins interacting with viral proteins during aging. From 22 DEGs in aged blood, FASLG, CTSW, CTSE, VCAM1, and BAG3 were associated with immune response, inflammation, cell component and adhesion, and platelet activation/aggregation. Males and females older than 50 years old overexpress FASLG, possibly inducing a hyperinflammatory cascade. The expression of cathepsins (CTSW and CTSE) and the anti-apoptotic co-chaperone molecule BAG3 also increased throughout aging in both genders. By exploring single-cell RNA-sequencing data from peripheral blood of SARS-CoV-2-infected patients, we found FASLG and CTSW expressed in natural killer cells and CD8 + T lymphocytes, whereas BAG3 was expressed mainly in CD4 + T cells, naive T cells, and CD14 + monocytes. In addition, T cell exhaustion was associated with increased expression of CCL4L2 and DUSP4 over blood aging. LAG3, PDCD1, TIGIT, VCAM1, HLA-DRA, and TOX also increased in individuals aged 60-69 years old; conversely, the RGS2 gene decreased with aging. We further identified a distinct gene expression profile associated with type I interferon signaling following blood aging. These results revealed changes in blood molecules potentially related to SARS-CoV-2 infection throughout aging, emphasizing them as therapeutic candidates for aggressive clinical manifestation of COVID-19. KEY MESSAGES: ⢠Prediction of host-viral interactions in the whole blood transcriptome during aging. ⢠Expression levels of FASLG, CTSW, CTSE, VCAM1, and BAG3 increase in aged blood. ⢠Blood interactome reveals targets involved with immune response, inflammation, and blood clots. ⢠SARS-CoV-2-infected patients with high viral load showed FASLG overexpression. ⢠Gene expression profile associated with T cell exhaustion and type I interferon signaling were affected with blood aging.
Assuntos
Envelhecimento/sangue , Proteínas Sanguíneas/análise , COVID-19/genética , SARS-CoV-2/patogenicidade , Transcriptoma , Adulto , Idoso , Envelhecimento/genética , Sangue/metabolismo , Análise Química do Sangue , Proteínas Sanguíneas/genética , Proteínas Sanguíneas/metabolismo , Vasos Sanguíneos/metabolismo , Vasos Sanguíneos/virologia , COVID-19/sangue , COVID-19/imunologia , COVID-19/fisiopatologia , Fenômenos Fisiológicos Cardiovasculares/genética , Sistema Cardiovascular/metabolismo , Sistema Cardiovascular/virologia , Estudos de Coortes , Feminino , Estudos de Associação Genética , Humanos , Imunidade Inata/genética , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
SAXSMoW (SAXS Molecular Weight) is an online platform widely used over the past few years for determination of molecular weights of proteins in dilute solutions. The scattering intensity retrieved from small-angle X-ray scattering (SAXS) raw data is the sole input to SAXSMoW for determination of molecular weights of proteins in liquid. The current updated SAXSMoW version 3.0 determines the linear dependence of the true protein volume on their apparent protein volume, based on SAXS curves calculated for 67,000 protein structures selected from the Protein Data Bank. SAXSMoW 3.0 was tested against 43 experimental SAXS scattering curves from proteins with known molecular weights. Our results demonstrate that most of the molecular weights determined for the nonglycosylated and also for the glycosylated proteins are in good agreement with their expected molecular weights. Additionally, the average discrepancies between the calculated molecular weights and their nominal values for glycosylated proteins are similar to those for nonglycosylated ones.
Assuntos
Bases de Dados de Proteínas , Simulação de Dinâmica Molecular , Proteínas/química , Espalhamento a Baixo Ângulo , Software , Difração de Raios X , Peso MolecularRESUMO
Phospholipases A2 (PLA2s) are found in almost every venomous snake family. In snakebites, some PLA2s can quickly cause local myonecrosis, which may lead to permanent sequelae if antivenom is administered belatedly. They hydrolyse phospholipids in membranes through a catalytic calcium ions-dependent mechanism. BthTX-II is a basic PLA2 and the second major component in the venom of Bothrops jararacussu. Herein, using the software SEQUENCE SLIDER, which integrates crystallographic, mass spectrometry and genetic data, we characterized the primary, tertiary and quaternary structure of two BthTX-II variants (called a and b), which diverge in 7 residues. Crystallographic structure BthTX-IIa is in a Tense-state with its distorted calcium binding loop buried in the dimer interface, contrarily, the novel BthTX-IIb structure is a monomer in a Relax-state with a fatty acid in the hydrophobic channel. Structural data in solution reveals that both variants are monomeric in neutral physiological conditions and mostly dimeric in an acidic environment, being catalytic active in both situations. Therefore, we propose two myotoxic mechanisms for BthTX-II, a catalytic one associated with the monomeric assembly, whereas the other has a calcium independent activity related to its C-terminal region, adopting a dimeric conformation similar to PLA2-like proteins.
RESUMO
The serine/arginine-rich protein kinase 2 (SRPK2) has been reported as upregulated in several cancer types, with roles in hallmarks such as cell migration, growth, and apoptosis. These findings have indicated that SRPK2 is a promising emerging target in drug discovery initiatives. Although high-resolution models are available for SRPK2 (PDB 2X7G), they have been obtained with a heavily truncated recombinant protein version (~50% of the primary structure), due to the presence of long intrinsically unstructured regions. In the present work, we sought to characterize the structure of a full-length recombinant version of SRPK2 in solution. Low-resolution Small-Angle X-ray Scattering data were obtained for both versions of SRPK2. The truncated ΔNΔS-SRPK2 presented a propensity to dimerize at higher concentrations whereas the full-length SRPK2 was mainly found as dimers. The hydrodynamic behavior of the full-length SRPK2 was further investigated by analytical size exclusion chromatography and sedimentation velocity analytical ultracentrifugation experiments. SRPK2 behaved as a monomer-dimer equilibrium and both forms have an elongated shape in solution, pointing to a stretched-to-closed tendency among the conformational plasticity observed. Taken together, these findings allowed us to define unique structural features of the SRPK2 within SRPK family, characterized by its flexible regions outside the bipartite kinase domain.
Assuntos
Hidrodinâmica , Modelos Moleculares , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Recombinantes , Conformação Proteica , Proteínas Serina-Treonina Quinases/genética , Soluções , Análise Espectral , Relação Estrutura-AtividadeRESUMO
Enzymes are essential in many biological processes, including second-generation ethanol production. However, enzymes are one of the main expenses for the industrial process in these days. Several studies have been done to maximize cost savings, however, many processes are still economically infeasible. In this study, we report the synthesis of a suspension of lignocresol for recycling or reuse of enzymes in bioprocesses. In this way, it was performed the adsorption assays between lignocresol and ß-glucosidases from Thermotoga petrophila, belonging to the families GH1 and GH3, for the development of a lignocresol-enzyme complex. Our results show that lignocresol maintains greater adsorptive capacity for ß-glucosidases than lignin. This capacity can be explained both by its great hydrophobicity and also by electrostatic characteristics. Therefore, all these results demonstrate good adsorption of the enzymes to the lignocresol, demonstrating great potential for enzymatic recycling.
RESUMO
Ferulic acid (FA), a low-molecular weight aromatic compound derived from lignin, represents a high-value molecule, used for applications in the cosmetic and pharmaceutical industries. FA can be further enzymatically converted in other commercially interesting molecules, such as vanillin and bioplastics. In several organisms, these transformations often start with a common step of FA activation via CoA-thioesterification, catalyzed by feruloyl-CoA synthetases (Fcs). In this context, these enzymes are of biotechnological interest for conversion of lignin-derived FA into high value chemicals. In this study, we describe the first structural characterization of a prokaryotic Fcs, named FCS1, isolated from a lignin-degrading microbial consortium. The FCS1 optimum pH and temperature were 9 and 37°C, respectively, with Km of 0.12 mM and Vmax of 36.82 U/mg. The circular dichroism spectra indicated a notable secondary structure stability at alkaline pH values and high temperatures. This secondary structure stability corroborates the activity data, which remains high until pH 9. The Small Angle X-Ray Scattering analyses resulted on the tertiary/quaternary structure and the low-resolution envelope in solution of FCS1, which was modeled as a homodimer using the hyperthermophilic nucleoside diphosphate-forming acetyl-CoA synthetase from Candidatus Korachaeum cryptofilum. This study contributes to the field of research by establishing the first biophysical and structural characterization for Fcs, and our data may be used for comparison against novel enzymes of this class that to be studied in the future.