The homeostasis of copper within the body needs to be tightly regulated as deficiency prevents the proper functioning of proteins reliant on copper as a cofactor, whilst excess levels of copper are toxic cells.
Copper is an essential component of many metalloproteins, for example superoxide dismutase (free radical protection), mitochondrial cytochrome-c oxidase (electron transport), tyrosinase (pigmentation) and lysyl oxidase (collagen processing)
4 comments:
THE ABILITY OF Cu TO CYCLE BETWEEN A STABLE OXIDISED, Cu (II), AND UNSTABLE REDUCED, Cu(I), STATES IS USED BY CUPROENZYMES INVOLVED IN REDOX REACTIONS, E.G. Cu/Zn SUPEROXIDE DISMUTASE AND CYTOCHROME OXIDASE.
The Cu(II) <--> Cu (I) transitions can in certain circumstances also result in the generation of reactive oxygen species, e.g. superoxide radical and hydroxyl radical, which, if not detoxified efficiently, can damage susceptible cellular components.
Copper can also bind with high affinity to histidine, cysteine and methionine residues of proteins which can result in their inactivation.
The need to provide Cu to essential enzymes without ensuing cellular toxicity has necessitated evolution of tightly regulated Cu homeostatic mechanisms.
Post a Comment