Spectrophotometric assay for protease activity in ionic liquids using chromogenic substrates

Kazunori Nakashima, Tatsuo Maruyama, Noriho Kamiya, Masahiro Goto

研究成果: Article査読

10 被引用数 (Scopus)


A new spectrophotometric assay has been developed to evaluate protease activity in ionic liquids (ILs). The assay consists of two strategies to enable real-time spectrometric analysis of enzymatic reaction in ILs. First, enzymes are modified with a comb-shaped poly(ethylene glycol), PM13, to obtain a transparent enzyme solution in IL. Second, a chromogenic substrate is used to follow the enzymatic reaction in IL. p-Nitroaniline-derivatized substrates are subjected to protease-catalyzed alcoholysis to release chromogenic p-nitroaniline that can be quantitatively detected by a UV-Vis spectrophotometer. By using this method, we can evaluate protease activity in ILs quite easily without separation of products from the reaction mixture. The availability of the novel assay system was demonstrated in a kinetic analysis of subtilisin-catalyzed reaction in the IL 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([Emim][Tf2N]) under different reaction conditions. Because two different serine proteases, subtilisin and α-chymotrypsin, substantially retained its original substrate specificity in the IL, the assay can be extended to other enzymes by using suitable chromogenic substrates.

ジャーナルAnalytical Biochemistry
出版ステータスPublished - 2008 3 15

ASJC Scopus subject areas

  • 生物理学
  • 生化学
  • 分子生物学
  • 細胞生物学


「Spectrophotometric assay for protease activity in ionic liquids using chromogenic substrates」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。