... pmol and 99 pmol of retinol per mg of total proteinafter 1 h of incubation with 10 lm and 20 lm of retinal, respectively. RDH2 enzymes were more effi-cient than RDH1 enzymes, and generated 64 and 134 ... active site (YTVAK) and the cofactor-binding motifs aremarked in bold. The D43, T67 and A69 residues, involved in cofactor specificity, are indicated by asterisks. Flanking the N-terminal hydropho-bic ... 2007)doi:10.1111/j.1742-4658.2007.05904.x In vertebrates, multiple microsomal retinol dehydrogenases are involved in reversible retinol ⁄ retinal interconversion, thereby controlling retinoid meta-bolism and retinoic acid...