[Effect of calcium ions on the interaction of troponin C with rabbit skeletal muscle troponin I and troponin T immobilized on polyvinyl chloride].
Using a new methodological approach based on the binding of 125I-labeled troponin C to troponins I and T immobilized on polyvinylchloride, the Ca2+-dependent interaction of troponin components was investigated. In the absence of Ca2+, two types of sites of troponin C--troponin T interaction were revealed (Kd = 3.6.10(-8) M and 5.10(-7) M). It was found that Ca2+ induced the formation of a troponin I--troponin C complex which was resistant to 5 M urea (Kd = 4.10(-8) M). In the absence of Ca2+, the binary troponin T--troponin C complex also revealed two types of interaction sites (Kd = 7.1.10(-8) M and 2.10(-7) M); however, in the presence of Ca2+ only high affinity sites whose number increased almost 2-fold were revealed. The events that may take place in the whole troponin complex during Ca2+ binding by troponin C are discussed.
Feoktistov
I A
IA
Krylatov
A V
AV
Zabeĭvorota
S I
SI
Cherviakov
E B
EB
Larionov
N P
NP
D000818:Animals; D052160:Benzothiazoles; D001667:Binding, Competitive; D002118:Calcium / Q000494:pharmacology*; D002232:Carbocyanines; D005456:Fluorescent Dyes; D066298:In Vitro Techniques; D009132:Muscles / Q000187:drug effects* / Q000378:metabolism; D011143:Polyvinyl Chloride; D011817:Rabbits; D014336:Troponin / Q000378:metabolism*; D019209:Troponin C; D019210:Troponin I; D020107:Troponin T; D014508:Urea
D052160:Benzothiazoles; D002232:Carbocyanines; D005456:Fluorescent Dyes; D014336:Troponin; D019209:Troponin C; D019210:Troponin I; D020107:Troponin T; C012944:3,3'-dipropyl-2,2'-thiadicarbocyanine; D014508:Urea; D011143:Polyvinyl Chloride; D002118:Calcium
Vliianie ionov kal'tsiia na vzaimodeĭstvie troponina C s immobilizaovannymi na polivinilkhloride troponine I i troponinom T skeletnykh myshts krolika.