Cross-linking of troponin with dimethylimido esters.
The topology of troponin, the calcium binding regulatory protein in muscle, has been studied by cross-linking with different length dimethylimido esters. The results show that the three components of troponin are close to each other and that the troponin-I and -T are preferentially cross-linked being 0.6 nm or less apart. The largest cross-linked product is a complex which corresponds in molecular weight to the native troponin complex of 1 mol of each of the three components. Cross-linked troponin has lost the ability to make the actomyosin ATPase calcium sensitive although it does bind to actin-tropomyosin and tropomyosin, and it binds calcium normally. No effect of calcium on cross-linking could be detected.
D000199:Actins; D000578:Amidines; D000818:Animals; D001665:Binding Sites; D002118:Calcium; D002645:Chickens; D004533:Egtazic Acid; D004952:Esters; D007094:Imides; D046911:Macromolecular Substances; D008970:Molecular Weight; D009124:Muscle Proteins; D009132:Muscles / Q000032:analysis; D011485:Protein Binding; D011487:Protein Conformation; D011817:Rabbits; D014335:Tropomyosin; D014336:Troponin
D000199:Actins; D000578:Amidines; D004952:Esters; D007094:Imides; D046911:Macromolecular Substances; D009124:Muscle Proteins; D014335:Tropomyosin; D014336:Troponin; D004533:Egtazic Acid; D002118:Calcium