title: Elasticity of mutant myosin subfragment-1 arranged on a functional silver surface.
abstract: Elasticity of a two-dimensionally arranged myosin subfragment-1 (S1) was measured by using a surface forces apparatus. To prepare a two-dimensionally arranged S1-monolayer on a functionalized silver surface, we used genetically engineered Dictyostelium S1 molecules. A highly reactive cysteine residue was fused to the COOH-terminus using the recombinant DNA method. On the other hand, the maleimide groups was self-assembled onto a silver surface. Then the mutant S1 molecules were chemically bound to the functionalized silver surface at its COOH-terminus. This arrangement technique was necessary in order to create a stable S1-monolayer by chemical bond formation onto the silver surface. The occupied area of the single S1 on the silver surface was about 110 nm(2). In the interaction between the S1-monolayer and mica surfaces in aqueous solution, a long-range attractive force was observed. The elastic constants (stiffness and Young's modulus) of myosin S1 were evaluated from force-distance profiles in aqueous solution, using the Hertz theory. We found that the stiffness (or spring constant) and Young's modulus of S1 in the absence of nucleotide are 4.4 +/- 1.0 pN/nm and 0.71 +/- 0.16 GPa, respectively.
authors.affiliation: Department of Biological Science and Technology, Tokai University, 317 Nishino, Numazu, Shizuoka, 410-0321, Japan. suda@fb.u-tokai.ac.jp
authors.forename: H
authors.initials: H
authors.lastname: Suda
authors.forename: Y C
authors.initials: YC
authors.lastname: Sasaki
authors.forename: N
authors.initials: N
authors.lastname: Oishi
authors.forename: N
authors.initials: N
authors.lastname: Hiraoka
authors.forename: K
authors.initials: K
authors.lastname: Sutoh
mesh_terms: D000538:Aluminum Silicates; D000595:Amino Acid Sequence; D000818:Animals; D001703:Biophysics / Q000295:instrumentation; D004023:Dictyostelium / Q000235:genetics; D004548:Elasticity; D009119:Muscle Contraction / Q000502:physiology; D009154:Mutation; D015879:Myosin Subfragments / Q000737:chemistry* / Q000235:genetics*; D015202:Protein Engineering; D011817:Rabbits; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D012834:Silver; D013499:Surface Properties
chemical_list: D000538:Aluminum Silicates; D015879:Myosin Subfragments; D011994:Recombinant Proteins; D012834:Silver; C011934:mica