ISSN:
1572-8773
Keywords:
Copper amine oxidase
;
Cobalt substitution
;
Pyrroloquinoline quinone (PQQ)
;
Copper-binding inhibitors
;
Carbonyl-binding inhibitors
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Summary The role of copper in bovine serum amine oxidase was investigated by studying the effect of copper-binding inhibitors on the reactions of the pyrroloquinoline quinone carbonyl and on the reaction with oxygen. Hydrazines and hydrazides were used as carbonyl reagents and one of the hydrazines, benzylhydrazine, which was found to behave as a pseudo-substrate, was used to probe the reaction with oxygen. The presence ofN,N-diethyldithiocarbamate, a chelator that binds copper irreversibly, did not prevent the reactions at the carbonyl, but slowed down their rate and modified the conformation of the adducts. The same happened to the reaction with oxygen, which was slowed down but not abolished. Copper, which was never seen in the reduced state, thus appears to control all reactions without being directly involved in the binding of either hydrazines or oxygen. The enzyme functionality was in fact preserved upon substitution of copper with cobalt. The specific activity of the cobalt-substituted enzyme was only reduced to about 40% the native amine oxidase value. This is the first case so far in which the role of copper can be performed by a different metal ion.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01179516
Permalink