Copper enzyme inhibition

Kubitz, J.A., E.C. Lewek, J.M. Besser, J.B. Drake III, and J.P. Giesy. 1995. Effects of copper-contaminated sediments on Hyalella azteca, Daphnia magna, and Ceriodaphnia dubia survival, growth, and enzyme inhibition. Arch. Environ. Contam. Toxicol. 29 97-103. 

CuZnSOD is inhibited by azide and cyanide and (like other copper enzymes)... 

Another possible biochemical mechanism of action for copper complex action is based upon the report that copper decreased the permeability of human synovial lysosomes obtained from arthritic patients by oxidizing membrane thiols to disulphides and, as a result, decreased the release of free lysosomal enzymes [80]. Membrane stabilization as opposed to lysosomal enzyme inhibition is also consistent with the observation that many copper complexes, with the exception of Cu(II)(niflumate)2, failed to inhibit cathepsin-D, a lysosomal proteinase [647]. 

C. Chronic use may increase the elimination of certain essential metals (copper, zinc) by chelation. This may, in part, be the cause of disulfiram s enzyme-inhibiting effects, as both of these enzymes require copper as a cofactor. 

Ghica ME, Carvalho RC, Amine A, Brett CMA (2013) Glucose oxidase enzyme inhibition sensors for heavy metals at carbon film electrodes modified with cobalt or copper hexacyanofeirate. Sensor Actuator B 178 270-278... 

The one-pot approach required some measures to prevent negative influence of one catalyst on another, namely immobilization of the enzyme onto a support (silica) to mitigate poisoning of copper by protein sulfur moieties and addition of a copper ion com-plexing agent (EDTA) to avoid enzyme inhibition by traces of copper ions that can be leached into the solution. 

In acidic solution, the degradation results in the formation of furfural, furfuryl alcohol, 2-furoic acid, 3-hydroxyfurfural, furoin, 2-methyl-3,8-dihydroxychroman, ethylglyoxal, and several condensation products (36). Many metals, especially copper, cataly2e the oxidation of L-ascorbic acid. Oxalic acid and copper form a chelate complex which prevents the ascorbic acid-copper-complex formation and therefore oxalic acid inhibits effectively the oxidation of L-ascorbic acid. L-Ascorbic acid can also be stabilized with metaphosphoric acid, amino acids, 8-hydroxyquinoline, glycols, sugars, and trichloracetic acid (38). Another catalytic reaction which accounts for loss of L-ascorbic acid occurs with enzymes, eg, L-ascorbic acid oxidase, a copper protein-containing enzyme. 

Red blood cells also contain sufficient acid phenylphospha-tase for mild hemolysis to cause false elevations. Therefore, inhibitors such as ethanol, formaldehyde, copper sulfate> and 1-tartrate have been used to inhibit selectively the enzyme of one or more tissues and enhance the specificity of the test (101). Ethanol is unsuitable because it inhibits the enzyme from erythrocytes and prostate simultaneously, and because it yields serum activities which correlate poorly with prostatic disease. Formaldehyde inhibits the erythrocytic enzyme and has been said to yield clinically satisfactory results. The copoper resistant acid phosphatase of serum is elevated by metastatic carcinoma of the breast, as well as by other metastatic cancers, and is also elevated by a wide variety of non-cancerous diseases. 

In contrast to the effects obtained with viruses mentioned earlier, rous sarcoma virus (RSV) is inactivated by direct contact with 2 [81]. Evidence for the drug action by a chelate compound was obtained by using concentrations of 3a and copper(II) sulfate, neither of which individually affected enzyme activity or transforming abilities [82]. In a later study these workers showed that several metal complexes inhibit the RNA dependent DNA polymerases and the transforming ability of RSV, the most active compound being a 1 1 copper(II)... 

Initial inhibition of sodium uptake and whole body sodium content that were normal by day 28. Abnormal liver enzyme activity. Liver copper increased from 23 mg/kg FW at start to 113 mg/kg FW at day 28... 

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