F·F ATP-synthase/ATPase of : Mystery of Unidirectional Catalysis.

F·F ATP synthases/ATPases (F·F) catalyze ATP synthesis by consuming energy of electrochemical potential of hydrogen ions (, or ATP hydrolysis resulting in the formation. It is generally accepted to consider F·F as a reversible chemomechanical-electrical molecular machine, however: (i) the mechanism of energy-dependent ATP synthesis is based only on the data on hydrolytic activity of the enzyme, (ii) F·F from a number of organisms effectively synthesize, but is unable to hydrolyze ATP, which indicates non-observance of the principle of microreversibility and requires development of a new hypotheses concerning the enzyme mechanism. Since 1980, the group of A. D. Vinogradov has been developing a concept according to which the elementary catalysis stages of ATP hydrolysis and ATP synthesis do not coincide, and there are two independently operating forms of F·F in the coupled membranes - -generating ATPase and -consuming ATP synthase. F·F of as a natural model of an irreversibly functioning enzyme is a convenient object for experimental verification of the hypothesis of unidirectional energy conversion. The review considers modern concepts of the molecular mechanisms of regulation of F·F ATP synthase/ATPase of and development of the hypothesis of two forms of F·F.