Impact of the removal of N-terminal non-structured amino acids on activity and stability of xylanases from Orpinomyces sp. PC-2
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Data
2017-08-03
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Editor
International Journal of Biological Macromolecules
Resumo
Xylanases catalyze the random hydrolysis of xylan backbone from plant biomass and thus, they have
application in the production of biofuels, Kraft pulps biobleaching and feed industry. Here, xylanases
derived from Orpinomyces sp. PC-2 were engineered guided by molecular dynamics methods to obtain
more thermostable enzymes. Based on these models, 27 amino acid residues from the N-terminal were
predicted to reduce protein stability and the impact of this removal was validated to two enzyme con-
structs: small xylanase Wild-Type (SWT) obtained from Wild-Type xylanase (WT) and small xylanase
Mutant (SM2) generated from M2 mutant xylanase (V135A, A226T). The tail removal promoted increase
in specific activity of purified SWT and SM2, which achieved 5,801.7 and 5,106.8 U mg^−1 of protein, respec-
tively, while the WT activity was 444.1 U mg^−1 of protein. WT, SWT and SM2 showed half-life values at
50 ◦ C of 0.8, 2.3 and 29.5 h, respectively. Overall, in view of the results, we propose that the presence of
non-structured amino acid in the N-terminal leads to destabilization of the xylanases and may promote
less access of the substrate to the active site. Therefore, its removal may promote increased stability and
enzymatic activity, interesting properties that make them suitable for biotechnological applications.
Descrição
Palavras-chave
Xylanase, Orpinomyces, Thermostability, Molecular dynamics simulation