Chromium complexes glutathione

The mechanism for clearance of chromium(VI) once reduced inside the liver cell may involve a chromium(III)-glutathione complex. The glutathione complex would be soluble through the cell membrane and capable of entering the bile (Norseth et al. 1982). The complexing of chromium(III) to other ligands has been shown to make them more permeable to the cell membrane (Warren et al. 1981). 

Kortenkamp A, Oetken G, Beyersmann D (1990) The DNA cleavage induced by chromium(V) complex and by chromium and glutathione is mediated by activated oxygen species. Mutation Res 232 155-161 Kunz BA, Kohalmi SE (1991) Modulation of mutagenesis by deoxyribonucleoside levels. Annu Rev Genet 25 339-359... 

Levina A, Zhang L, Lay PA. 2003. Stracture and reactivity of a chromium(V) glutathione complex. Inorg Chem 42(3) 767-784. 

A. Levina and P. A. Lay, Solution structures of chromium(V) complexes with glutathione and model thiols, Inorg. Chem., 43 (2004) 324-335. 

P. O Brian, J. Pratt, F. J. Swanson, P. Thornton, and G. Wang, Chromium(V) containing complex from the reaction of glutathione with chromate, Inorg. Chim. Acta, 169 (1990) 265-269. 

The amino acids believed to be involved in GTF are the constituents of the naturally occurring tripeptide glutathione (256). Anderson et al. have reported a complex of glutathione/nicotinic acid and chromium(III) to be particularly active in their in vitro assay.1198 The complex was described as being purified by HPLC, but the details of the preparation are not available. 

However at neutral pH, solutions of chromium(VI) containing an excess of glutathione (1 10) rapidly develop a green colour,1454 which slowly decays to a purple colour typical of chromium(III) complexes. Concurrent with the green colour the typical EPR spectrum of a chromium(V) species is observed. Chromium(V) has also been observed in the EPR spectrum of frozen glasses obtained from reaction mixtures of chromium(VI) and glutathione.1455... 

It has been proposed that GTF is related to a dinicotinatotris(amino acid)chromium(III) complex, which forms a ternary complex at the membrane receptor with insulin. Porcine insulin binds a Cr(nic)2(glutathione) complex very tightly. 

Hexavalent chromium has no known essential function. However, trivalent chromium in the form of a dinicotinic acid-glutathione complex is an essential cofactor for insulin production and forms complexes with protein, amino acids, and other organic acids. 

Kortenkamp A, Beyersman D, O Brien P (1987) Uptake of chromium(III) complexes by erythrocytes. Toxicol Environ Chem 14 23 Kortenkamp A, Ozolins Z, Beyersmann D, O Brien P (1989) Generation of PM2 DNA breaks in the course of reduction of chromium(VI) by glutathione. Mutation Res 216 19-26... 

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