Establishment of mesophilic-like catalytic properties in a thermophilic enzyme without affecting its thermal stability

Satoshi Akanuma, Mizumo Bessho, Hikono Kimura, Ryutaro Furukawa, Shin ichi Yokobori, Akihiko Yamagishi

研究成果: Article

1 引用 (Scopus)

抜粋

Thermophilic enzymes are generally more thermally stable but are less active at moderate temperatures than are their mesophilic counterparts. Thermophilic enzymes with improved low-temperature activity that retain their high stability would serve as useful tools for industrial processes especially when robust biocatalysts are required. Here we show an effective way to explore amino acid substitutions that enhance the low-temperature catalytic activity of a thermophilic enzyme, based on a pairwise sequence comparison of thermophilic/mesophilic enzymes. One or a combination of amino acid(s) in 3-isopropylmalate dehydrogenase from the extreme thermophile Thermus thermophilus was/were substituted by a residue(s) found in the Escherichia coli enzyme at the same position(s). The best mutant, which contained three amino acid substitutions, showed a 17-fold higher specific activity at 25 °C compared to the original wild-type enzyme while retaining high thermal stability. The kinetic and thermodynamic parameters of the mutant showed similar patterns along the reaction coordinate to those of the mesophilic enzyme. We also analyzed the residues at the substitution sites from a structural and phylogenetic point of view.

元の言語English
記事番号9346
ジャーナルScientific reports
9
発行部数1
DOI
出版物ステータスPublished - 2019 12 1

    フィンガープリント

ASJC Scopus subject areas

  • General

これを引用