title: Specific interaction between GroEL and denatured protein measured by compression-free force spectroscopy.
abstract: We investigated the interaction between GroEL and a denatured protein from a mechanical point of view using an atomic force microscope. Pepsin was bound to an atomic force microscope probe and used at a neutral pH as an example of denatured proteins. To measure a specific and delicate interaction force, we obtained force curves without pressing the probe onto GroEL molecules spread on a mica surface. Approximately 40 pN of tensile force was observed for approximately 10 nm while pepsin was pulled away from the chaperonin after a brief contact. This length of force duration corresponding to the circumference of GroEL's interior cavity was shortened by the addition of ATP. The relation between the observed mechanical parameters and the chaperonin's refolding function is discussed.
authors.affiliation: Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Midori-ku, Yokohama, Kanagawa 226-8501, Japan. hsekiguc@bio.titech.ac.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sekiguchi
authors.forename: Hideo
authors.initials: H
authors.lastname: Arakawa
authors.forename: Hideki
authors.initials: H
authors.lastname: Taguchi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ito
authors.forename: Ryohei
authors.initials: R
authors.lastname: Kokawa
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ikai
mesh_terms: D000255:Adenosine Triphosphate / Q000737:chemistry*; D001665:Binding Sites; D018834:Chaperonin 60 / Q000737:chemistry* / Q000648:ultrastructure*; D019245:Compressive Strength; D004548:Elasticity; D006863:Hydrogen-Ion Concentration; D046911:Macromolecular Substances; D018625:Microscopy, Atomic Force / Q000379:methods*; D015335:Molecular Probes; D010434:Pepsin A / Q000737:chemistry* / Q000648:ultrastructure*; D011485:Protein Binding; D013314:Stress, Mechanical
chemical_list: D018834:Chaperonin 60; D046911:Macromolecular Substances; D015335:Molecular Probes; D000255:Adenosine Triphosphate; D010434:Pepsin A