An actin-binding site on the 20K fragment of myosin subfragment 1.
Myosin subfragment 1 (S1) was covalently labeled with a fluorescent dye, N-[7-(dimethylamino)-4-methyl-3-coumarinyl]maleimide (DACM), and then digested by trypsin to cleave S1 heavy chain into fragments. The DACM-labeled and trypsin-treated S1 was complexed with F-actin and treated with a zero-length cross-linker, 1-ethyl-3[3-(dimethylamino)propyl] carbodiimide (EDC). The cross-linking reaction generated a covalently linked complex of actin and the 20K fragment of S1 heavy chain, which exclusively incorporated the fluorescent dye, to form a fluorescent 65K cross-linked product. The 20K and 65K fluorescent peptides were isolated and purified and then subjected to cyanogen bromide and/or hydroxylamine cleavages. Mapping of fluorescent cleavage products on acrylamide gels revealed that the N-terminal 20 residues of the 20K fragment of S1 heavy chain contained a cross-linking site of actin.
D000199:Actins / Q000378:metabolism*; D000818:Animals; D001665:Binding Sites; D008301:Maleimides / Q000494:pharmacology; D008970:Molecular Weight; D009132:Muscles / Q000378:metabolism; D015879:Myosin Subfragments; D009218:Myosins / Q000378:metabolism*; D010446:Peptide Fragments / Q000032:analysis / Q000378:metabolism*; D011485:Protein Binding; D011817:Rabbits; D013439:Sulfhydryl Reagents / Q000494:pharmacology; D014357:Trypsin
D000199:Actins; D008301:Maleimides; D015879:Myosin Subfragments; D010446:Peptide Fragments; D013439:Sulfhydryl Reagents; C019347:N-(7-dimethylamino-4-methylcoumarinyl)maleimide; D014357:Trypsin; D009218:Myosins