Copper in biological systems

The need for a Greek key fold remains obscure. The apoproteins are clearly stable without metals there are examples other than immunoglobulins of Greek key folds. So far copper seems to be found in a very limited subset of structures other chapters in this volume show that zinc, for example, has a much wider variety of environments in proteins, as does iron. It may be that the copper-containing Greek key proteins represent a very small evolutionary niche. Structures of other copper proteins will undoubtedly reveal new surprises and help to clarify the essential role of copper in biological systems. 

COPPER (In Biological Systems), The activity of copper in plant metabolism manifests itself in two forms 11) synthesis of chlorophyll, and 12) activity of enzymes. In leaves, most of the copper occurs in close association with chlorophyll, but little is known of ns rale in chlorophyll synthesis, other than the presence of cupper is required. Copper is a definite constituent of several enzymes catalyzing oxidation-reduction reactions (oxidases), in which the activity is believed to be due to the shuttling of copper between the +1 and +2 oxidalicm states,... 

The principal micronutrients and their deficiencies in soils of the United States are shown in Table 3. Even though the traditional micronutrients may be required only in minute quantities, deficiencies can lead to diseased crops and stunted livestock. See also entries on Boron Copper (In Biological Systems) Iron Manganese Molybdenum (In Biological Systems) and Zinc (In Biological Systems). 

The critical role of copper in biological systems has been recognized for a long time. Copper is an essential component for living systems, although excess intake causes symptoms such as Wilson s disease. Numerous copper-containing proteins are now known and can be categorized based on their functions as follows ... 

Hamilton and co-workers (27, 28) have suggested Cu(III) as a probable intermediate in the reaction catalyzed by galactose oxidase. Papers by Kosman and co-workers (29, 30) seem at variance with this interpretation. Regardless of the outcome of this dispute, we hope that our evidence for the existence and properties of Cu(III)—peptide complexes will encourage more investigations of the presence of trivalent copper in biological systems. Our work shows that this oxidation state is readily attained under biological conditions. 

Malkin, R., Malmstrom, B. G. The state and function of copper in biological systems, in Advances in Enzymology and Related Areas of Molecular Biology, 33 (ed.) Nord, F. F., p. 177, New York, Interscience 1970... 

The oxidation state of copper in biological systems is -1-1 or +2. Copper(III) is found in inorganic systems and may occur as a reaction intermediate in galactose oxidase, laccase (a plant enzyme), and perhaps other enzymes. The coordination number of copper in these enzymes ranges from two to six and occasionally higher. 

MaUdn R, Malmstrom BG. 1970. State and function of copper in biological systems. Adv Enzymol 33 177-244. 

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