[Regularities in the kinetic of photoactivation of lactate dehydrogenase by the action of UV light in different microenvironment].
The kinetics of photoinactivation of cardiac (H4) and muscular (M4) isoforms of lactate dehydrogenase irradiated by UV light (240-390 nm) in the free form and in the presence of sodium azide, D-mannitol, and serotonin was studied. It was shown that the decrease in the catalytic activity of both enzymes can be described by the kinetics of the first-order monomolecular reaction. The inactivation rate constant of lactate dehydrogenase M4 is considerably higher than that of lactate dehydrogenase H4, indicating a greater photochemical lability of the isoform M4. It was shown that sodium azide has a different protective action on the proteins studied. The irradiation of the muscular isoform in the presence of serotonin and D-mannitol did not change the character of the "dose-effect" curve and only led to a decrease in the photoinactivation rate constant of the protein.
Artiukhov
V G
VG
Voronezh State University, Russia.
Lysenko
Iu A
IuA
Nakvasina
M A
MA
D000818:Animals; D004789:Enzyme Activation; D007527:Isoenzymes / Q000737:chemistry / Q000528:radiation effects; D007700:Kinetics; D007770:L-Lactate Dehydrogenase / Q000737:chemistry* / Q000528:radiation effects*; D009124:Muscle Proteins / Q000737:chemistry / Q000528:radiation effects; D014466:Ultraviolet Rays
D007527:Isoenzymes; D009124:Muscle Proteins; D007770:L-Lactate Dehydrogenase
Kineticheskie zakonomernosti fotoaktivatsii laktatdegidrogenazy pod deĭstviem UF-izlucheniia v usloviiakh razlichnogo mikrookruzheniia.