Structural redesign of lipase B from Candida antarctica by circular permutation and incremental truncation.

ABSTRACT: Circular permutation of Candida antarctica lipase B yields several enzyme variants with substantially increased catalytic activity. To better understand the structural and functional consequences of protein termini reorganization, we have applied protein engineering and x-ray crystallography to cp283, one of the most active hydrolase variants. Our initial investigation has focused on the role of an extended surface loop, created by linking the native N- and C-termini, on protein integrity. Incremental truncation of the loop partially compensates for observed losses in secondary structure and the permutants' temperature of unfolding. Unexpectedly, the improvements are accompanied by quaternary-structure changes from monomer to dimer. The crystal structures of one truncated variant (cp283 De

SUBMITTER: Qian Z 

PROVIDER: S-EPMC2753740 | biostudies-literature | 2009 Oct

REPOSITORIES: biostudies-literature