Metabolism and Glucose Tolerance Factor Activity of Synthetic Amino acid- Chromium Complexes in Yeast

The Glucose Tolerance Factor (GTF), a chromium containing complex, has been isolated from yeast by Schwartz & Mertz. This was instrumental in the recognition of the role of trivalent chromium, complexed to amino acids, in regulation of glucose metabolism and of active GTF as a potential antidiabetic agent. We report herein on newly devised simple, synthetic procedures for soluble binary AA-Cr (1:1) complexes of known structure(s) and on their activities in S.cerevisiae. Lys.Cr permits post exponential growth of yeast and prevents apoptosis, unlike free lysine which inhibits post exponential growth and cell viability. Phe.Cr is a better sole carbon source for yeast than the free amino acid and complexation, in this case, enhances the rate of metabolism of its carbon skeleton. In addition, Phe.Cr as well as Gln.Cr, but not Lys.Cr, exhibit considerable GTF-like activity in yeast. The results obtained suggest that soluble AA.Cr are good model compounds for exploring structure activity correlations that determine the role of trivalent chromium in cellular metabolism.