Studies on the stability of an enzyme-inhibitor complex using a mechanism-based inhibitor of dopamine. beta. -hydroxylase

Conference · Fri May 01 04:00:00 EDT 1987 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:6023987

Flory, Jr, D R; Villafranca, J J

The authors have previously reported that a number of 3-phenyl-1-propenes behave as mechanism-based inhibitors of dopamine ..beta..-hydroxylase (D..beta..H). Several of these inhibitors have been shown to lead to irreversible loss of enzyme activity. One of these inhibitors was synthesized as the tritiated analog, 2-(/sup 3/H)-3-(p-OH-phenyl)-1-propene, in order to determine the stoichiometry of inhibitor bound and to be used as an active site probe. They report here that the stoichiometry of inhibitor binding by 2-(/sup 3/H)-(p-OH-phenyl)-1-propene varies under several dialysis conditions. Up to 65% of initially bound inhibitor is lost from the enzyme upon dialysis in either 4M urea or 6M guanidine-HCl. This loss is seen at both pH 6.0 and pH 8.0. When inactivated enzyme is treated with hydroxylamine there is again a large loss of the radioactive label.

• Research Organization: Pennsylvania State Univ., University Park
• OSTI ID: 6023987
• Report Number(s): CONF-870644-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 46:6
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINES
AROMATICS
AUTONOMIC NERVOUS SYSTEM AGENTS
BIOCHEMICAL REACTION KINETICS
CARDIOTONICS
CARDIOVASCULAR AGENTS
DOPAMINE
DRUGS
ENZYME INHIBITORS
ENZYMES
HYDROXY COMPOUNDS
HYDROXYLASES
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
NEUROREGULATORS
ORGANIC COMPOUNDS
OXIDOREDUCTASES
PHENOLS
POLYPHENOLS
REACTION KINETICS
STABILITY
STOICHIOMETRY
SYMPATHOMIMETICS
TRACER TECHNIQUES
TRITIUM COMPOUNDS