title: Single-molecule imaging of the dynamic interactions between macromolecules.
abstract: In recent years, the development of single-molecule detection techniques has allowed the dynamic properties of biomolecules, which are normally obscured in conventional ensemble measurements, to be measured. One of these single-molecule detection techniques allows the measurement of dissociation and association events of individual molecules to be measured. This technique is based on the unique premise that the mobility between molecules that are bound and the mobility between those that are free in solution are different. The binding of ATP at the beginning and its dissociation at the end of the hydrolysis reaction were detected at the single-molecule level in real time. In this study, we extended this technique to image the dynamic interactions between large biomolecules (protein/protein and protein/polysaccharide). The binding and dissociation of fluorescently labeled macromolecules to partner molecules fixed on a glass surface were visualized by total internal reflection fluorescence microscopy. The dynamic interactions between the proteins in two energy conversion systems, that is, signaling proteins and enzyme molecules moving on dextran, have been measured. In these systems, the dynamic interactions were sensitive to the factors determining the chemical reactions. Thus, the dynamic interactions monitored in the single-molecule measurements provided useful information to further the understanding of the underlying mechanisms of energy conversion systems.
authors.affiliation: Single Molecule Processes Project, ICORP JST, Osaka 562-0035, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Yokota
authors.forename: Kuniyoshi
authors.initials: K
authors.lastname: Kaseda
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Matsuura
authors.forename: Yushiyuki
authors.initials: Y
authors.lastname: Arai
authors.forename: Atsuko
authors.initials: A
authors.lastname: Iwane
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Ishii
authors.forename: Takao
authors.initials: T
authors.lastname: Kodama
authors.forename: Toshio
authors.initials: T
authors.lastname: Yanagida
mesh_terms: D000255:Adenosine Triphosphate / Q000737:chemistry*; D019921:Biotinylation; D003911:Dextrans / Q000737:chemistry; D004926:Escherichia coli / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000737:chemistry; D007091:Image Processing, Computer-Assisted; D046911:Macromolecular Substances / Q000737:chemistry*; D008856:Microscopy, Fluorescence / Q000379:methods*; D036103:Nanotechnology / Q000379:methods*; D011134:Polysaccharides / Q000737:chemistry; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D016986:Streptococcus sobrinus / Q000378:metabolism; D013997:Time Factors
chemical_list: D003911:Dextrans; D046911:Macromolecular Substances; D011134:Polysaccharides; D011993:Recombinant Fusion Proteins; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate; D005982:Glutathione Transferase