title: High-pressure enzyme kinetics. Lactate dehydrogenase in an optical cell that allows a reaction to be started under high pressure.
abstract: A newly designed optical cell allows an enzyme reaction to be started under high pressure and makes it possible to begin measurement of the reaction rate after a 'dead time' no longer than 1-2 s. This device was used to study the kinetics of lactate dehydrogenase reaction at 1 kbar. At this pressure lactate dehydrogenase from rabbit muscle exhibited a rapid deactivation in the presence of NADH if pyruvate was absent. After addition of pyruvate the reaction was initiated and proceeded at a constant rate, i.e., without loss of enzyme activity. It is suggested that pyruvate markedly increases the association constant of this tetrameric enzyme.
mesh_terms: D000818:Animals; D006874:Hydrostatic Pressure; D007700:Kinetics; D007770:L-Lactate Dehydrogenase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D046911:Macromolecular Substances; D009132:Muscles / Q000201:enzymology; D009243:NAD / Q000494:pharmacology; D011312:Pressure; D011773:Pyruvates / Q000494:pharmacology; D019289:Pyruvic Acid; D011817:Rabbits; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*
chemical_list: D046911:Macromolecular Substances; D011773:Pyruvates; D009243:NAD; D019289:Pyruvic Acid; D007770:L-Lactate Dehydrogenase