Identification of myosin-binding sites on the actin sequence.
The rigor complex of actin and trypsin-treated myosin subfragment 1 (S1) whose heavy chain was cleaved into three fragments (20K, 25K, and 50K) was cross-linked with a zero-length cross-linker, 1-ethyl-3-[3-(dimethyl-amino) propyl]carbodiimide. The cross-linking reaction generated three types of cross-linked products with apparent molecular weights of 65K, 68K, and 95K. The 65K, 68K, and 95K products were covalently linked complexes of actin-20K fragment of the S1 heavy chain, actin-alkaline light chain 1, and actin-50K fragment of the S1 heavy chain, respectively. Cross-linking sites of S1 heavy and light chains on the actin sequence have been determined by digesting the cross-linked products with cyanogen bromide or with hydroxylamine and then mapping resulting peptides on sodium dodecyl sulfate gels. The result indicates that some of the N-terminal acidic residues of actin at positions 1, 2, 3, 4, and 11 are cross-linking sites of the 20K and 50K fragments of the S1 heavy chain while some of its C-terminal acidic residues at positions 360, 362, and 363 are cross-linking sites of the alkaline light chain 1.
D000199:Actins / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D003432:Cross-Linking Reagents; D003488:Cyanogen Bromide; D008301:Maleimides; D008970:Molecular Weight; D009132:Muscles / Q000378:metabolism; D009218:Myosins / Q000378:metabolism*; D010446:Peptide Fragments / Q000032:analysis; D011485:Protein Binding; D011817:Rabbits; D013439:Sulfhydryl Reagents; D014357:Trypsin
D000199:Actins; D003432:Cross-Linking Reagents; D008301:Maleimides; D010446:Peptide Fragments; D013439:Sulfhydryl Reagents; C019347:N-(7-dimethylamino-4-methylcoumarinyl)maleimide; D014357:Trypsin; D009218:Myosins; D003488:Cyanogen Bromide