Indicators for suicide substrate inactivation: A kinetic investigation

The mechanism of suicide-inactivation of tyrosinase: a substrate structure investigation.

Tyrosinase is a copper-containing mono-oxygenase, widely distributed in nature, able to catalyze the oxidation of both phenols and catechols to the corresponding ortho-quinones. Tyrosinase is characterised by a hitherto unexplained irreversible inactivation which occurs during the oxidation of catechols. Although the corresponding catechols are formed during tyrosinase oxidation of monophenols,...

Kinetic studies on the inactivation of L-lactate oxidase by [the acetylenic suicide substrate] 2-hydroxy-3-butynoate.

2-Hydroxy-3-butynoate is both a substrate and an irreversible inactivator of the flavoenzyme L-lactate oxidase. The partitioning between catalytic oxidation of 2-hydroxy-3-butynoate and inactivation of the enzyme is determined by the concentration of the second substrate, O2. Rapid reaction studies show the formation of an intermediate which is common to both the oxidation and inactivation path...

THE FRANK KINETIC MODEL FOR SPONTANEOUS CHIRAL SYMMETRY BREAKING WITH VARIABLE CONCENTRATION OF THE ACHIRAL SUBSTRATE

This paper considers the possibility of spontaneous transition of aracemic mixture (composed of equal amounts of two enantiomeric species, say L and D) into a monochiral state (in which only one enantiomer, say L, is present). Transitions of this kind have been recently experimentally observed. A plausible approach to this phenomenon is a model put forward by Frank, based on simple laws of ...

Suicide in the elderly: a beginning investigation.

“Suicide” Inactivation of Thromboxane A2 Synthase

“Suicide” inactivation occurs during catalysis by thromboxane synthase. Loss of enzymatic activity, accompanying thromboxane BP formation, was proportional to the substrate concentration. Inactivation was directly related to product formation: for several different experimental protocols 50% loss of thromboxane synthase activity corresponded with formation of 454 f 79 ng of thromboxane B,/mg pr...