The role of local residue environmental changes in thermostable mutants of the GH11 xylanase from Bacillus subtilis

Autor(es)

Silva, Sergio Bergamachi ; Pinheiro, Matheus Pinto ; Fuzo, Carlos Alessandro ; Silva, Samuel Reghim ; Ferreira, Tatiane Lopes ; Lourenzoni, Marcos Roberto ; Nonato, M. Cristina ; Vieira, Davi Serradella ; Ward, Richard John

• Tipo de documento: Artigo Científico
• Fonte: International Journal of Biological Macromolecules; v. 97, p. 574-584, APR 2017.
• Citações Web of Science: 2

Resumo

A thermostable variant of the mesophilic xylanase A from Bacillus subtilis (BsXynA-G3\_4x) contains the four mutations Gln7His, Gly13Arg, Ser22Pro, and Ser179Cys. The crystal structure of the BsXynA-G3\_4x has been solved, and the local environments around each of these positions investigated by molecular dynamics (MD) simulations at 328 K and 348 K. The structural and MD simulation results were correlated with thermodynamic data of the wild-type enzyme, the 4 single mutants and the BsXynA-G3\_4x. This analysis suggests that the overall stabilizing effect is entropic, and is consistent with solvation of charged residues and reduction of main-chain flexibility. Furthermore, increased protein-protein hydrogen bonding and hydrophobic interactions also contribute to stabilize the BsXynA-G3\_4x. The study revealed that a combination of several factors is responsible for increased thermostability of the BsXynA-G3\_4x; (i) introduction of backbone rigidity in regions of high flexibility, (ii) solvation effects and (iii) hydrophobic contacts. (C) 2017 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 10/18850-2 - Identificação, caracterização e engenharia de enzimas que degradam a parede celular das plantas
• Beneficiário: Richard John Ward
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 09/50838-5 - Determinantes de estabilidade estrutural de enzimas xilanases termofílicas mutantes por dinâmica molecular: efeitos da glicosilação sobre a termoestabilidade
• Beneficiário: Davi Serradella Vieira
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 12/01066-2 - Desenho de enzimas multifuncionais que combinam a hidrólise de B-Glucanos e xilanos para avaliação da conformação destes polissacarídeos na parede celular de plantas
• Beneficiário: Matheus Pinto Pinheiro
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado