title: Subunit unbinding mechanics of dimeric wheat germ agglutinin (WGA) studied by atomic force microscopy.
abstract: Wheat germ agglutinin (WGA) is an oligomeric lectin widely used as a model of sugar moieties in biochemistry. Subunit association is important for the crosslinking function of WGA, so we used atomic force microscopy to measure the subunit unbinding force of dimeric WGA. We found that the average unbinding force of dimeric WGA is ∼55 pN at ∼1 nN/s loading rate, whereas this unbinding force is increased at least up to 100 pN when WGA is bound to glycophorin A. Moreover, the dissociation rate constant of WGA was calculated to be 1–2 × 10(−2) s(−1), suggesting that dimer dissociation is relatively fast.
authors.affiliation: Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku 152-8550, Japan; Innovation Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan. rafrinr@gmail.com
authors.forename: Rehana
authors.initials: R
authors.lastname: Afrin
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ikai
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry; D002021:Buffers; D006021:Glycophorins / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D055767:Immobilized Proteins / Q000737:chemistry / Q000378:metabolism; D018625:Microscopy, Atomic Force; D056004:Molecular Dynamics Simulation; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D021122:Protein Subunits / Q000737:chemistry* / Q000378:metabolism; D013499:Surface Properties; D014909:Wheat Germ Agglutinins / Q000737:chemistry* / Q000378:metabolism
chemical_list: D000538:Aluminum Silicates; D002021:Buffers; D006021:Glycophorins; D055767:Immobilized Proteins; D021122:Protein Subunits; D014909:Wheat Germ Agglutinins; C011934:mica