TROPONIN: STRUCTURE, PROPERTIES AND MECHANISM OF FUNCTIONING
V.L. Filatov, A.G. Katrukha, T.V. Bulargina, N.B. Gusev Department of Bioorganic Chemistry, School of Biology, Lomonosov Moscow State University, Moscow 119899, Russia; fax: (7-095)939-2788, E-mail: filatov@soil.msu.ru Scientific-Research Institute of Medical Ecology, Moscow 113149, Simpheropolsky bul, 8, Russia; fax: (095)939-2788, E- mail: katrukha@soil.msu.ru Department of Biochemistry, School of Biology, Lomonosov Moscow State University, Moscow 119899, Russia; fax: (095)939-3955, E-mail: gusev@gusev.bio.msu.su
The review considers structure and properties of isolated troponin components, their interaction, and mechanism of regulation of contractile activity of skeletal and cardiac muscle. The data on the structure of troponin C in the crystal form and in solution are presented. Conformational changes induced by Ca2+ binding to various sites of troponin C are described. The structure of troponin 1 is analyzed and its interaction with other components of the actin filaments is discussed. The data on phosphorylation of troponin I by various protein kinases are presented. The role of troponin 1 phosphorylation in the regulation of contractile activity of the heart is discussed. The structural properties of troponin T and its interaction with other components of the thin filament are described. The data on troponin T phosphorylation are presented and the effect of troponin T phosphorylation on contractile activity of various muscles is discussed. Modern models of troponin functioning are presented and analyzed.