title: Uniquely stable 40 kDa subfragment-2 in carp myosin.
abstract: Digestion of carp myofibrils at 30 degrees C in 0.5 M KCl medium with calcium ion generated unique 135 kDa heavy meromyosin (HMM). The HMM was not produced when digested at 10 degrees C. A further digestion of the 135 kD HMM isolated in the absence of calcium ion generated uniquely short subfragment-2 (S-2) with a size of 40 kDa (40 kDa S-2) together with subfragment-1 (S-1). The 40 kDa S-2 was identified by N- and C-end sequencing, and demonstrated to locate the amino end of the rod portion. The unfolding temperature for the 40 kDa S-2 was around 52 degrees C as studied by circular dichroism measurement. The same unfolding peak was also detected with the intact rod together with a large unfolding peak at around 36 degrees C coming from the rest of the rod portion, light meromyosin. The unfolding peak for the 40 kDa S-2 in myosin was a little lower (48 degrees C) than that in free form, suggesting the involvement of the head portion in the stability of the 40 kDa S-2 in the structure.
authors.affiliation: Laboratory of Marine Food Sciences, Graduate School of Fisheries Sciences, Hokkaido University, Hakodate, Hokkaido 041-8611, Japan.
authors.forename: Tomoko Tazawa
authors.initials: TT
authors.lastname: Takahashi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Takahashi
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Konno
mesh_terms: D000818:Animals; D002347:Carps; D002918:Chymotrypsin / Q000378:metabolism; D004355:Drug Stability; D006358:Hot Temperature; D008970:Molecular Weight; D009210:Myofibrils / Q000737:chemistry*; D015879:Myosin Subfragments / Q000737:chemistry / Q000378:metabolism; D009218:Myosins / Q000737:chemistry*; D010446:Peptide Fragments / Q000737:chemistry* / Q000378:metabolism; D017510:Protein Folding
chemical_list: D015879:Myosin Subfragments; D010446:Peptide Fragments; D002918:Chymotrypsin; D009218:Myosins