title: Possible contribution of titin filaments to the compliant series elastic component in horseshoe crab skeletal muscle fibers.
abstract: In horseshoe crab skeletal muscle fibers, the extension of SEC at the maximum isometric force P0 is about 6% of the slack fiber length L0 (sarcomere length, 7 microns), i.e., about 210 nm per half-sarcomere, being too large to be explained by the cross-bridge and the thin filament elasticities. Cinematographic studies of isometrically contracting myofibril bundes indicate that the highly compliant SEC mostly originates from the "elastic" thick filament misalignment in each A-band during isometric force generation. Possible contribution of the titin filaments to the "elastic" thick filament misalignment is discussed.
authors.affiliation: Department of Physiology, School of Medicine, Teikyo University, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Sugi
authors.forename: T
authors.initials: T
authors.lastname: Akimoto
authors.forename: T
authors.initials: T
authors.lastname: Kobayashi
authors.forename: S
authors.initials: S
authors.lastname: Suzuki
authors.forename: M
authors.initials: M
authors.lastname: Shimada
mesh_terms: D000818:Animals; D002118:Calcium / Q000502:physiology; D064211:Connectin; D004548:Elasticity; D006737:Horseshoe Crabs; D066298:In Vitro Techniques; D007537:Isometric Contraction / Q000502:physiology*; D018485:Muscle Fibers, Skeletal / Q000502:physiology*; D009124:Muscle Proteins / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D009210:Myofibrils / Q000502:physiology*; D009218:Myosins / Q000502:physiology; D011494:Protein Kinases / Q000502:physiology*; D012518:Sarcomeres / Q000502:physiology
chemical_list: D064211:Connectin; D009124:Muscle Proteins; D011494:Protein Kinases; D009218:Myosins; D002118:Calcium