Search PubMed⌕ Search

Biomedical subjects

A Stracher

Publications and source records attributed to A Stracher.

64 records · Page 4Linked to original sources
PubMed1971

Identification of the essential light chains of myosin.

The molecular weights of light chains associated with adult and embryonic chick myosin have been determined by polyacrylamide gel electrophoresis in the presence of 0.1% sodium dodecyl sulfate. Adult muscle myosin contains three light chains with molecular weights averaging 27,700, 21,000, and 16,500, while the embryonic form contains only the two largest of these three. Recombination and hybridization experiments have been performed with these samples. The data clearly demonstrate that only two light chains are required for the expression of the full ATPase activity of myosin. The third light chain consistently is associated with adult myosin, but definitive evidence for its role is lacking.

Adenosine Triphosphatases↗
PubMed1967

Subunits and their interactions.

There is fairly general agreement that myosin isolated from rabbit skeletal muscle has a molecular weight of about 500,000. The higher values that have been reported apparently reflect protein aggregation related to the method of preparation. On the basis of present evidence, the myosin molecule has an elongate helical core of two f subunits (average weight about 215,000) that extend into a globular head region containing three g subunits (average weight about 20,000). Myosin may be dissociated into subunits by a number of methods. In 5 M guanidine, the myosin molecule is dissociated into f and g subunits, while at pH above 10, the g subunits are dissociated from the intact fibrous core of myosin. The dissociation of g subunits at pH 10 is accompanied by the loss of both ATPase activity and actin-binding capacity; however, the exact biological significance of the g subunits is presently uncertain. In preliminary studies, the f subunits appear to contain the sulfhydryl residues currently implicated in myosin ATPase, and there is some indication of allosteric regulation of enzymic activity.

Adenosine Triphosphatases↗
PubMedDate not supplied

The effect of protease inhibitors, leupeptin and E64d, on differentiation of C2C12 myoblasts in tissue culture.

Intracellular calcium levels play an important role in myofibril disintegration and regeneration of muscle fibers. Earlier studies have shown that the calcium activated protease, calpain, is involved in the removal of Z-discs from myofibrils of striated muscle and the tripeptide-aldehyde, leupeptin, which is an inhibitor of calpain, inhibits this activity. In the present communication, we demonstrate that leupeptin and another calpain inhibitor, E64d, inhibit the fusion of mouse skeletal muscle C2C12 myoblasts to form multinucleated myotubes in tissue culture.

Animals↗