Elucidation of catalytic mechanisms as well as subunit-assembly of nitrile hydratase family enzymes by using advanced structural studies

2014 Fiscal Year Final Research Report

• Project/Area Number: 24350082
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Chemistry related to living body
• Research Institution: Akita University (2014); Tokyo University of Agriculture and Technology (2012-2013)
• Principal Investigator: ODAKA Masafumi 秋田大学, 工学(系)研究科(研究院), 教授 (20224248)
• Co-Investigator(Renkei-kenkyūsha): KUROKI Ryota 独立行政法人日本原子力研究開発機構, 量子ビーム応用研究部門, ユニット長 (30391246) ; YOHDA Masafumi 東京農工大学, 大学院工学研究院, 教授 (50250105)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 時間分割結晶構造解析 / 翻訳後修飾 / システインスルフェン酸 / 酵素反応 / 触媒機構 / 反応中間体 / 水和反応 / 結晶構造

Outline of Final Research Achievements

Catalytic reaction of a Fe-type nitrile hydratase betaR56K mutant was studied by time-resolved crystallography. The results showed that the metal-coordinated substrate is nucleophilically attacked by the O(SO-) atom of alphaCys114-SO-;, followed by nucleophilic attack of the S(SO-) atom by a betaArg56-activated water molecule to release the product amide and regenerate alphaCys114-SO-;. Also, kinetic as well as crystallographic studies on the mutant SCNases revealed that both NHase and SCNase share the catalytic mechanism and that the size and shape of their substrate binding pockets are predominantly control the substrate selectivity.

Free Research Field

生体関連化学