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Publication Abstract from PubMed

Thermostable enzymes have many advantages for industrial applications. Therefore, in this study, computer-aided design technology was used to improve the thermostability of a highly active endo-polygalacturonase from Talaromyces leycettanus JCM12802 at an optimal temperature of 70 degrees C. The melting temperature and specific activity of the obtained mutant T316C/G344C were increased by 10 degrees C and 36.5%, respectively, compared with the wild-type enzyme. The crystal structure of the T316C/G344C mutant showed no formation of a disulfide bond between the introduced cysteines, indicating a different mechanism than the conventional mechanism underlying improved enzyme thermostability. The cysteine substitutions directly formed a new alkyl hydrophobic interaction and caused conformational changes in the side chains of the adjacent residues Asn315 and Thr343, which in turn caused a local reconstruction of hydrogen bonds. This method greatly improved the thermostability of the enzyme without affecting its activity; thus, our findings are of great significance for both theoretical research and practical applications.

Cysteine Engineering of an Endo-polygalacturonase from Talaromyces leycettanus JCM 12802 to Improve Its Thermostability.,Wang S, Meng K, Su X, Hakulinen N, Wang Y, Zhang J, Luo H, Yao B, Huang H, Tu T J Agric Food Chem. 2021 Jun 9;69(22):6351-6359. doi: 10.1021/acs.jafc.1c01618., Epub 2021 May 27. PMID:34043362^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.