Biotechnology Letters 2008-09-01

Alteration of metal ions improves the activity and thermostability of aminoacylase from hyperthermophilic archaeon Pyrococcus horikoshii.

Motomu Nishioka, Koichi Tanimoto, Noriko Higashi, Harumi Fukada, Kazuhiko Ishikawa, Masahito Taya

文献索引：Biotechnol. Lett. 30(9) , 1639-43, (2008)

全文：HTML全文

摘要

Recombinant L-aminoacylase (PhoACY) from a hyperthermophilic archeon, Pyrococcus horikoshii, is a zinc-containing metalloenzyme. When the zinc was substituted by Mn(2+) or Ni(2+), its specific activity was significantly increased with acetyl-L-methionine as a substrate. The thermostability of PhoACY was improved when it was incubated with 1 mM Zn(2+), Mn(2+) or Ni(2+). The enzyme with external Zn(2+) addition had no significant loss of the activity when held at 90 degrees C for up to 12 h and moreover had more than a 10-fold longer half-life even at 100 degrees C, compared to the enzyme without Zn(2+) addition. A thermostable structure of the enzyme associated with zinc binding is described based on differential scanning calorimetry.