Single-molecule analysis of 1-nm stepping motion of linear motor carbohydrate hydrolase

2014 Fiscal Year Final Research Report

• Project/Area Number: 24370062
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Biophysics
• Research Institution: Okazaki Research Facilities, National Institutes of Natural Sciences (2014); The University of Tokyo (2012-2013)
• Principal Investigator: IINO RYOTA 大学共同利用機関法人自然科学研究機構(岡崎共通研究施設), 岡崎統合バイオサイエンスセンター, 教授 (70403003)
• Co-Investigator(Kenkyū-buntansha): UCHIHASHI Takayuki 金沢大学, 数物科学系, 准教授 (30326300) ; IGARASHI Kiyohiko 東京大学, 農学生命科学研究科, 准教授 (80345181)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 分子モーター / １分子計測

Outline of Final Research Achievements

In this study, using single-molecule fluorescence microscopy and high speed atomic force microscopy, we determined kinetic constants of the elementary reaction steps for carbohydrate hydrolase TrCel7A against cellulose Iα and IIII. TrCel7A displayed similar binding and dissociation rate constants for cellulose Iα and IIII and similar fractions of productive binding on cellulose Iα and IIII. Furthermore, once productively bound, TrCel7A processively hydrolyzes and moves along cellulose Iα and IIII with similar translational rates. With structural models of cellulose Iα and IIII, we propose that different susceptibilities at high TrCel7A concentration arise from surface properties of substrate, including ratio of hydrophobic surface and number of available lanes.

Free Research Field

生物物理学