Expression, Characterization, and Structural Analysis of Human Liver Delta4-3-Ketosteroid 5beta-Reductase (AKR1D1) and Its Disease-Related Mutant P133R
January 2009
in “
ScholarlyCommons (University of Pennsylvania)
”
TLDR The P133R mutation in AKR1D1 enzyme causes harmful bile acid buildup, explaining related health issues.
The study focused on the human liver enzyme delta4-3-ketosteroid 5beta-reductase (AKR1D1) and its disease-related mutant P133R. Researchers successfully expressed and purified active recombinant AKR1D1, allowing for detailed structural and functional analysis. The enzyme was capable of 5β-reduction of various steroid precursors, indicating its broad substrate specificity. Structural studies provided the first X-ray crystal structures of AKR1D1 in complex with NADP+ and several steroids, revealing insights into its catalytic mechanism. The P133R mutant exhibited altered kinetic parameters, leading to the accumulation of hepatotoxic allo-bile acids, explaining the clinical symptoms associated with this mutation. This study enhanced the understanding of AKR1D1's role in steroid metabolism and its implications in deficiency syndromes.