[Estimation of the distance between sulfhydryl groups S1 and specific binding centers for divalent metal ions in myosin].
Interlocation of sulfhydryl groups S1 and corresponding divalent ions binding sites in myosin has been studied. S1-SH groups were labelled with iodacetamide spin labels and their saturation curves were measured in the presence of Ca2+ and Mn2+. The spin-lattice relaxation rates 1/T1 of labels were calculated from saturation curves and according to their changes caused by replacing Ca2+ by Mn2+ the distance between sulfhydryl groups S1 and divalent ions binding sites were estimated to be 45 +/- 2.5 A. The addition of ATP to this system has not changed the character of interaction. An analysis of saturation curves measured within temperature range 20-100 K suggests that two myosin subfragments J differ in conformation at least in the range where S1-SH groups are located.
D000255:Adenosine Triphosphate / Q000378:metabolism; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D008345:Manganese / Q000378:metabolism; D009218:Myosins / Q000378:metabolism
D008345:Manganese; D000255:Adenosine Triphosphate; D009218:Myosins; D002118:Calcium
Otsenka rasstoianiia mezhdu sul'fgidril'nymi gruppami S1 i tsentrami spetsificheskogo sviazyvaniia ionov dvukhvalentnykh metallov v miozine.