Changes in the binding of copper in the plasma of molybdenum supplemented rats.
After incubating plasma of Mo-supplemented rats (Mo-plasma) with 64Cu only part of it could be removed by dialysis against EDTA or histidine or by treatment with dithiocarbamate; this nondialyzable Cu was shown to be bound to albumin. The maximal amount of 64Cu bound this way equaled the Mo-induced increase in total plasma Cu. After addition of stable Cu, dialysis of Mo-plasma against a histidine solution showed that no extra Cu became tightly bound, suggesting that the 64Cu binding was due to an exchange between added 64Cu and stable Cu already present. Incubating Mo-plasma with Hg compounds prevented 64Cu binding and released stable Cu, indicating that Cu in Mo-plasma was sulfhydryl bound. Part of the Mo in Mo-plasma was freely dialyzable. The remaining part was shown to be SH bound as well. The estimated atomic ratio of SH-bound Cu and Mo was unity. Molybdenum increased the number of SH groups in plasma, and for each Cu atom at least one SH group was calculated to be present.
D000818:Animals; D001798:Blood Proteins / Q000378:metabolism*; D003300:Copper / Q000097:blood*; D007700:Kinetics; D008297:Male; D008982:Molybdenum / Q000097:blood / Q000494:pharmacology*; D011485:Protein Binding; D011868:Radioisotopes; D051381:Rats; D011919:Rats, Inbred Strains
D001798:Blood Proteins; D011868:Radioisotopes; D003300:Copper; D008982:Molybdenum