Absence of Evidence for Metabolite-Modulated Association between α-Glycerol-3-phosphate Dehydrogenase and l-Lactate Dehydrogenase

Evidence for the NADH-modulated formation of a complex between α-glycerol-3-phosphate dehydrogenase and l-lactate dehydrogenase was reported [Yong, H., Thomas, G. A., and Peticolas, W. L. (1993) Biochemistry 32, 11124−11131]. This NADH-modulated association suggested a mechanism of potentially great importance to enzyme modulation and the controversial phenomena of direct NADH channeling. In the present paper, we reproduce with additional controls the experiments described by Yong et al. ((1993) Biochemistry 32, 11124−11131). Our results conclusively demonstrate the absence of detectable association between α-glycol-3-phosphate dehydrogenase and l-lactate dehydrogenase.