Biomaterial Database

Regulatory light chain contents and molecular species of myosin in catch muscle of scallop. 1982

F Morita, and S Kondo

Myosin purified from the smooth muscle of scallop adductor contains two kinds of regulatory light chain, regulatory light chain a (RLC-a) and regulatory light chain b (RLC-b) (Kondo, S. & Morita, F. (1981) J. Biochem. 90, 673). The myosin was fractionated by salting out with ammonium sulfate, and samples containing the two regulatory light chains with different molar ratios were obtained. ATPase activities of the myosin fractions were determined. From the analysis of the dependence of ATPase activity on molar ratio of the two regulatory light chains, we concluded that myosin purified from the smooth muscle of scallop contains three species of myosin having different combinations of regulatory light chains: one has two RLC-a (aa), another has two RLC-b (bb), and the third one each of RLC-a and RLC-b (ab). The order of ATPase activities of these three myosin species was estimated as (aa) less than (bb) less than (ab). Distribution of the two regulatory light chains in the smooth muscle from the inside, translucent portion to the outside, opaque portion was examined by means of one- and two-dimensional gel electrophoreses. The content of RLC-b was about 1 mol per mol of SH-light chain independent of the portion of muscle. The content of RLC-a was markedly dependent on the portion of muscle--about 0.2 mol per mol of SH-light chain in the innermost portion and 0.7 mol per mol of SH-light chain in the outside, opaque portion. The sum of both regulatory light chain contents was about 1.5 mol per mol of SH-light chain in the opaque portion where the catch contraction is notable. Myosin species in the catch muscle are discussed.

UI	MeSH Term	Description	Entries
D008974	Mollusca	A phylum of the kingdom Metazoa. Mollusca have soft, unsegmented bodies with an anterior head, a dorsal visceral mass, and a ventral foot. Most are encased in a protective calcareous shell. It includes the classes GASTROPODA; BIVALVIA; CEPHALOPODA; Aplacophora; Scaphopoda; Polyplacophora; and Monoplacophora.	Molluscs,Mollusks,Mollusc,Molluscas,Mollusk
D009130	Muscle, Smooth	Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)	Muscle, Involuntary,Smooth Muscle,Involuntary Muscle,Involuntary Muscles,Muscles, Involuntary,Muscles, Smooth,Smooth Muscles
D009218	Myosins	A diverse superfamily of proteins that function as translocating proteins. They share the common characteristics of being able to bind ACTINS and hydrolyze MgATP. Myosins generally consist of heavy chains which are involved in locomotion, and light chains which are involved in regulation. Within the structure of myosin heavy chain are three domains: the head, the neck and the tail. The head region of the heavy chain contains the actin binding domain and MgATPase domain which provides energy for locomotion. The neck region is involved in binding the light-chains. The tail region provides the anchoring point that maintains the position of the heavy chain. The superfamily of myosins is organized into structural classes based upon the type and arrangement of the subunits they contain.	Myosin ATPase,ATPase, Actin-Activated,ATPase, Actomyosin,ATPase, Myosin,Actin-Activated ATPase,Actomyosin ATPase,Actomyosin Adenosinetriphosphatase,Adenosine Triphosphatase, Myosin,Adenosinetriphosphatase, Actomyosin,Adenosinetriphosphatase, Myosin,Myosin,Myosin Adenosinetriphosphatase,ATPase, Actin Activated,Actin Activated ATPase,Myosin Adenosine Triphosphatase
D000251	Adenosine Triphosphatases	A group of enzymes which catalyze the hydrolysis of ATP. The hydrolysis reaction is usually coupled with another function such as transporting Ca(2+) across a membrane. These enzymes may be dependent on Ca(2+), Mg(2+), anions, H+, or DNA.	ATPases,Adenosinetriphosphatase,ATPase,ATPase, DNA-Dependent,Adenosine Triphosphatase,DNA-Dependent ATPase,DNA-Dependent Adenosinetriphosphatases,ATPase, DNA Dependent,Adenosinetriphosphatases, DNA-Dependent,DNA Dependent ATPase,DNA Dependent Adenosinetriphosphatases,Triphosphatase, Adenosine
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia