title: Heat-induced formation of myosin oligomer-soluble filament complex in high-salt solution.
abstract: Heat-induced aggregation of myosin into an elastic gel plays an important role in the water-holding capacity and texture of meat products. Here, we investigated thermal aggregation of porcine myosin in high-salt solution over a wide temperature range by dynamic light scattering experiments. The myosin samples were readily dissolved in 1.0 M NaCl at 25 °C followed by dilution into various salt concentrations. The diluted solutions consistently contained both myosin monomers and soluble filaments. The filament size decreased with increasing salt concentration and temperature. High temperatures above Tm led to at least partial dissociation of soluble filaments and thermal unfolding, resulting in the formation of soluble oligomers and binding to the persistently present soluble filaments. Such a complex formation between the oligomers and filaments has never been observed. Our results provide new insight into the heat-induced myosin gelation in high-salt solution.
authors.affiliation: Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Shimada
authors.affiliation: Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573, Japan.
authors.forename: Eisuke
authors.initials: E
authors.lastname: Takai
authors.affiliation: AminoScience Laboratories, Ajinomoto Inc., 1-1 Kawasaki, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Ejima
authors.affiliation: Alliance Protein Laboratories, San Diego, CA 92121, USA.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Arakawa
authors.affiliation: Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573, Japan. Electronic address: shiraki@bk.tsukuba.ac.jp.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Shiraki
mesh_terms: D006358:Hot Temperature; D057446:Hydrodynamics; D009218:Myosins / Q000737:chemistry*; D055503:Protein Multimerization / Q000187:drug effects* / Q000528:radiation effects*; D058767:Protein Unfolding; D012492:Salts / Q000737:chemistry* / Q000494:pharmacology*; D012965:Sodium Chloride / Q000737:chemistry / Q000494:pharmacology; D012995:Solubility; D012996:Solutions / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D012492:Salts; D012996:Solutions; D012965:Sodium Chloride; D009218:Myosins
keywords: Dynamic light scattering; Filament formation; Heat-induced gelation; Myosin; Thermal aggregation