Panteleeva, N. S., Bíró, N. A., Karandashov, E. A., Fábián, F., Krasovskaya, I. E., Kuleva, N. V. & Skvortsevich, E. G.

18O-exchange catalyzed by myosin, heavy meromyosin, heavy meromyosin subfragment 1 and their complexes with actin.

Acta Biochim Biophys Acad Sci Hung 12, 37-44.

Myosin, HMM and HMM S1 catalyze 18O-exchange between P1 and H218O of the medium at an intermediate stage of ATP hydrolysis ("intermediate 18O-exchange") in the presence of Mg2+. Natural complexes of actomyosin and acto-HMM S1 do not catalyze intermediate 18O-exchange but facilitate "direct" or "medium" 18O-exchange (KH2P18O4 in equilibrium H2O) even without ATP. Reconstituted complexes of actomyosin, acto-HMM, acto-HMM S1, PABC-HMM S1, congo-myosin and TNP-myosin do not catalyze direct 18O-exchange in the presence of Mg2+ and absence of ATP. From the data obtained a hypothetical sequence of phosphorylation and 18O-exchange reactions in myofibril action has been suggested.

Long, L., Fábián, F., Mason, D. T. & Wikman-Coffelt, J.

A new cardiac myosin characterized from the canine atria.

Biochem Biophys Res Commun 76, 626-35.

Fábián, F., Mason, D. T. & Wikman-Coffelt, J.

Calcium binding properties of cardiac and skeletal muscle myosins.

FEBS Lett 81, 381-5.