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Effect of modification of citraconic anhydrides on catalytic activity and thermostability of enzymes
Author(s) -
Matsumoto Michiaki,
Nakagawa Takashi,
Uchida Yosuke,
Seki Kumiko,
Ohba Masayoshi,
Kondo Kazuo
Publication year - 2016
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.4556
Subject(s) - thermostability , lipase , subtilisin , chemical modification , chemistry , chymotrypsin , lysine , enzyme , organic chemistry , biochemistry , amino acid , trypsin
BACKGROUND Activation and stabilization of enzymes have received considerable attention. In recent years, chemical modification has re‐emerged as a powerful complementary approach to site‐directed mutagenesis and directed evolution because it is simple and effective. Chemical modification of enzymes by dicarboxylic acid anhydride enhanced their activities and stabilities. RESULTS Lipase, α‐chymotrypsin and subtilisin modified by citraconic anhydride were examined. Lipase and α‐chymotrypsin were successfully modified by citraconic anhydride, while subtilisin showed poor reactivity with it. Optimum pH range for lipase and α‐chymotrypsin, and the secondary structure of α‐chymotrypsin was found to be unchanged by the modification process. Effect of the modification on the activity and thermostability of lipase was small. On the other hand, modification of lysine residues on the enzyme surface enhanced the catalytic activity and thermostability of α‐chymotrypsin. Further modification of lysine residues caused the reduction of thermostability. Modification of more hydrophobic dicarboxylic acid anhydride resulted in an increase in thermostability. CONCLUSION The modification of the lysine residues on the enzyme surface with citraconic anhydride shows a small effect on the catalytic reactivity and enhances the thermostability of the enzymes. © 2014 Society of Chemical Industry