HOMOLOGY OF THE ALPHA-CHAINS OF CARDIAC AND SKELETAL RABBIT TROPOMYOSIN

The similarity of the α subunits of rabbit cardiac and skeletal muscle tropomyosin was examined. Primary structures were compared by examining the digestion products formed after treatment with cyanogen bromide and trypsin. The peptides formed appeared similar on polyacrylamide gel electrophoresis both in the presence and absence of sodium dodecyl sulphate. Tryptic peptide mapping also confirmed the similarity of the peptides including those containing the single cysteine residue in the cardiac and skeletal α sub-units. This knowledge will enable crystallographic data obtained from rabbit cardiac tropomyosin crystals to be interpreted by comparison with the known primary sequence of rabbit skeletal α-tropomyosin. © 1979.