Acta NaturaeActa Naturae2075-8251Acta Naturae Ltd1059710.32607/20758251-2013-5-3-126-129Research ArticleStabilization of the Central Part of Tropomyosin Molecule Alters the Ca 2+-sensitivity of Actin-Myosin InteractionShchepkinD. V.levitsky@inbi.ras.ruMatyushenkoA. M.levitsky@inbi.ras.ruKopylovaG. V.levitsky@inbi.ras.ruArtemovaN. V.levitsky@inbi.ras.ruBershitskyS. Y.levitsky@inbi.ras.ruTsaturyanA. K.levitsky@inbi.ras.ruLevitskyD. I.levitsky@inbi.ras.ruInstitute of Immunology and PhysiologyBach Institute of Biochemistry, Russian Academy of SciencesInstitute of Mechanics, Lomonosov Moscow State UniversityBelozersky Institute of Physico-Chemical Biology150920135312612917012020Copyright © 2013, Shchepkin D.V., Matyushenko A.M., Kopylova G.V., Artemova N.V., Bershitsky S.Y., Tsaturyan A.K., Levitsky D.I.2013<p>We show that the mutations D137L and G126R, which stabilize the central part of the tropomyosin (Tm) molecule, increase both the maximal sliding velocity of the regulated actin filaments in the in vitro motility assay at high Са 2+ concentrations and the Са 2+-sensitivity of the actin-myosin interaction underlying this sliding. Based on an analysis of the recently published data on the structure of the actin-Tmmyosin complex, we suppose that the physiological effects of these mutations in Tm can be accounted for by their influence on the interactions between the central part of Tm and certain sites of the myosin head.</p>actin-myosin interactionin vitro motility assayregulation of muscle contractiontropomyosinактинискусственная подвижная системамиозинрегуляция мышечного сокращениятропомиозин[[1] McKillop D.F.A., Geeves M.A. // Biophys. J. 1993, V.65, P.693-701][[2] Nevzorov I.A., Levitsky D.I. // Biochemistry (Moscow). 2077, V.76, №13, P.1507-1527][[3] Sumida J.P., Wu E., Lehrer S.S. // J. Biol. Chem. 2008, V.283, P.6728-6734][[4] Nevzorov I.A., Nikolaeva O.P., Kainov Y.A., Redwood C.S., Levitsky D.I. // J. Biol. Chem. 2011, V.286, P.15766-15772][[5] Shchepkin D.V., Kopylova G.V., Nikitina L.V., Katsnelson L.B., Bershitsky S.Y. // Biochem. Biophys. Res. Commun. 2010, V.401, №1, P.159-163][[6] Homsher E., Kim B., Bobkova A., Tobacman L.S. // Biophys. J. 1996, V.70, P.1881-1892][[7] Mashanov G.I., Molloy J.E. // Biophys. J. 2007, V.92, №6, P.2199-2211][[8] Behrmann E., Müller M., Penczek P.A., Mannherz H.G., Manstein D.J., Raunser S. // Cell. 2010, V.150, №2, P.327-338][[9] Lehman W., Craig R. // Adv. Exp. Med. Biol. 2008, V.644, P.95-109]