We have sequenced a cDNA that encodes the nonmuscle myosin heavy chain from Drosophila melanogaster. An alternatively spliced exon at the 5' end generates two distinct heavy-chain transcripts: the longer transcripts inserts an additional start codon upstream of the primary translation start site and encodes a myosin heavy chain with a 45-residue extension at its amino terminus. The remainder of...

The sarcomeric proteins and organization of cardiac myofibrils appeared intact in multiple unrelated patients with hypertrophic cardiomyopathy. In two subjects demonstrating the missense mutation at position 403 (Arg to Gln) in the 13-myosin heavy chain gene, total myosin and immunoreactive 3-myosin heavy chain levels were similar to those found in other patients with hypertrophic cardiomyopath...

The sarcomeric proteins and organization of cardiac myofibrils appeared intact in multiple unrelated patients with hypertrophic cardiomyopathy. In two subjects demonstrating the missense mutation at position 403 (Arg to Gln) in the 13-myosin heavy chain gene, total myosin and immunoreactive 3-myosin heavy chain levels were similar to those found in other patients with hypertrophic cardiomyopath...

The sarcomeric proteins and organization of cardiac myofibrils appeared intact in multiple unrelated patients with hypertrophic cardiomyopathy. In two subjects demonstrating the missense mutation at position 403 (Arg to Gln) in the beta-myosin heavy chain gene, total myosin and immunoreactive beta-myosin heavy chain levels were similar to those found in other patients with hypertrophic cardiomy...

Skinned fibers from the normal human heart with the f3-myosin heavy chain (ventricular fibers) revealed both a higher force generation per cross section and a higher Ca2' sensitivity than skinned fibers with the a-myosin heavy chain (atrial fibers). The relation between isometric ATPase activity and isometric tension of atrial fibers was higher than that of ventricular fibers. Since the ATPase-...

The NH2-terminal 36 residues of the heavy chain and the NH2-terminal 40 residues of the light chain from a human Waldenström's IgM with binding activity for phosphorylcholine (phosphocholine) are compared with the published sequences of five mouse IgA myeloma proteins with the same activity. An extensive structural similarity; i.e., 3 amino acid interchanges within framework residues, and one i...