Mutational effects on thermostable superoxide dismutase from Aquifex pyrophilus: Understanding the molecular basis of protein thermostability

Jae Hwan Lim, Kwang Yeon Hwang, Juhyun Choi, Duck Yeon Lee, Byung-Yoon Ahn, Yunje Cho, Key Sun Kim, Ye Sun Han

Research output: Contribution to journalArticle

19 Citations (Scopus)


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 T1/2 value of K12A was 210 min and that of the wild type was 175 min at 95°C. However, the thermostability of the mutant E41A, which has a T1/2 value of 25 min at 95°C, 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.

Original languageEnglish
Pages (from-to)263-268
Number of pages6
JournalBiochemical and Biophysical Research Communications
Issue number1
Publication statusPublished - 2001 Oct 19



  • Aquifex pyrophilus
  • Hydrogen bonds
  • Ion pair network
  • Superoxide dismutase
  • Thermostability

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology

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