Earticle

초록

영어

Electrostatic interactions are important in protein folding, binding, flexibility, stability and function. When we look at the enzyme function, one of the key modulators of the active site residues are electrostatic interactions. The pH at which the enzyme is maximally active is determined by the pKa of the active site residues, which are modulated by several factors including by the change in electrostatics in its vicinity. Here, in this study, we focus on charged only substitutions to modulate the pKa of the active site residues in Bacillus circulans xylanase. Neutral residues are substituted by the charged ones (Glu, Arg) in such a way that the substituted residue can make direct interaction with the catalytic residues. Especially, the cases with other titratable residues (Asp, Tyr, Ser, Arg, Lys and His) present in native xylanase in between the catalytic sites and the substituted sites are avoided. And all the mutation sites are chosen closer to acid/base catalyst. Site directed mutagenesis was conducted to confirm the strategy. The results show the shift in pH optima of the mutants towards acidic side by 0.5 to 1.5 unit. The details will be presented and discussed.

키워드

저자

• Subarna POKHREL [ School of Chemical and Biological Engineering, Seoul National University, Seoul, Korea. ]
• Young Je YOO [ School of Chemical and Biological Engineering, Seoul National University, Seoul, Korea. ]

참고문헌

발행기관

간행물

표지보기 관심저널 등록

• 간행물명

  한국생물공학회 학술대회

• 간기

  반년간

• 수록기간

  1985~2013

• 십진분류

  KDC 476 DDC 576