Mammalian skeletal muscle C-protein: purification from bovine muscle, binding to titin and the characterization of a full-length human cDNA.
We report a fast method for the isolation of homogeneous C-protein from bovine skeletal muscle. In electron micrographs C-protein appears as short rods with a relatively uniform length of about 50 nm. Protein sequencing shows a single N-terminal sequence. Radio-labelled C-protein strongly decorates titin II and myosin rods but not myosin heads. Binding to titin II is retained in preparations lacking titin-associated proteins. Antibodies to bovine C-protein were used to screen a lambda gt11 cDNA library constructed from fetal human skeletal muscle. Clone HC38 is 3833 bp long and encodes a protein of 1138 amino acid residues. The start of the predicted sequence fits the N-terminal sequence of the bovine protein. All partial sequences obtained from the bovine protein (348 residues) and the sequence deduced from a partial chicken cDNA (Einheber and Fischman, 1990) can be aligned along the human sequence. The sequences of human and chicken C-proteins share 50% identity and 70% similarity. Along the repeat patterns of the human protein the fibronectin (Fn)-like domains are better conserved than the immunoglobulin (Ig)-like domains. Regions of strong divergence between chicken fast C-protein and human slow C-protein may represent differences in C-protein isoforms.
Fürst
D O
DO
Max-Planck-Institute for Biophysical Chemistry, Department of Biochemistry, Goettingen, FRG.
Vinkemeier
U
U
Weber
K
K
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins; D002417:Cattle; D002942:Circular Dichroism; D064211:Connectin; D004247:DNA; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007457:Iodine Radioisotopes; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism* / Q000648:ultrastructure; D009132:Muscles / Q000378:metabolism*; D011485:Protein Binding; D011494:Protein Kinases; D017386:Sequence Homology, Amino Acid; D000099163:Myosin Binding Protein C
D002352:Carrier Proteins; D064211:Connectin; D004247:DNA; D007457:Iodine Radioisotopes; D009124:Muscle Proteins; D011494:Protein Kinases; D000099163:Myosin Binding Protein C; C577285:TTN protein, human