Lim, JH Hwang, KY Choi, JY Lee, DY Ahn, BYY Cho, YJ Kim, KS Han, YS 2024-01-21T11:42:54Z 2024-01-21T11:42:54Z 2021-09-05 2001-10 0006-291X https://pubs.kist.re.kr/handle/201004/140157 We designed two mutants of superoxide dismutase (SOD), one is thermostable and the other is thermolabile, which provide valuable insight to identify amino acid residues essential for the thermostability of the SOD from Aquifex pyrophilus (ApSOD). The mutant K12A, in which Lys12 was replaced by Ala, had increased thermostability compared to that of the wild type. The T-1/2 value of K12A was 210 min and that of the wild type was 175 min at 95 degreesC. However, the thermostability of the mutant E41A, which has a T-1/2 value of 25 min at 95 degreesC, was significantly decreased compared to the wild type of ApSOD. To explain the enhanced thermostability of K12A and thermolabile E41A on the structural basis, the crystal structures of the two SOD mutants have been determined. The results have clearly shown the general significance of hydrogen bonds and ion-pair network in the thermostability of proteins. (C) 2001 Academic Press English ACADEMIC PRESS INC ELSEVIER SCIENCE Mutational effects on thermostable superoxide dismutase from Aquifex pyrophilus: Understanding the molecular basis of protein thermostability Article 10.1006/bbrc.2001.5752 1 BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, v.288, no.1, pp.263 - 268 BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS 288 1 263 268 N scie scopus 000171813400040 2-s2.0-0035914001 Biochemistry & Molecular Biology Biophysics Biochemistry & Molecular Biology Biophysics Article CONFORMATIONAL STABILITY GLUTAMATE-DEHYDROGENASE CRYSTAL-STRUCTURE SALT BRIDGES ION-PAIRS KEY ROLE DETERMINANTS ENZYME FORCES thermostability superoxide dismutase Aquifex pyrophilus hydrogen bonds ion pair network