Relationship of human liver dihydrodiol dehydrogenases to hepatic bile-acid-binding protein and an oxidoreductase of human colon cells.
We previously isolated three monomeric dihydrodiol dehydrogenases, DD1, DD2 and DD4, from human liver, and cloned a cDNA (C9) thought to encode DD2, which is identical with those for human bile-acid-binding protein and an oxidoreductase of human colon carcinoma HT29 cells. In the present study we have provided evidence that the C9 cDNA clone encodes DD1, not DD2. A recombinant enzyme expressed from the cDNA in a bacterial system was purified, and its catalytic properties, bile-acid-binding ability and primary sequence were compared with those of the hepatic dihydrodiol dehydrogenases. The results show that DD1 encoded by C9 possesses prostaglandin F synthase activity but low affinity for lithocholic acid, whereas DD2, showing differences of six amino acid residues from the DD1 sequence, exhibited high-affinity binding for the bile acid. Refined relationship between dihydrodiol dehydrogenases and their related proteins of human tissues is proposed.
Hara
A
A
Biochemistry Laboratory, Gifu Pharmaceutical University, Japan.
Matsuura
K
K
Tamada
Y
Y
Sato
K
K
Miyabe
Y
Y
Deyashiki
Y
Y
Ishida
N
N
D000595:Amino Acid Sequence; D001483:Base Sequence; D002352:Carrier Proteins / Q000378:metabolism*; D003106:Colon / Q000166:cytology / Q000201:enzymology*; D018076:DNA, Complementary; D006801:Humans; D006913:Hydroxysteroid Dehydrogenases; D008099:Liver / Q000201:enzymology*; D008562:Membrane Glycoproteins; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D014407:Tumor Cells, Cultured; D045002:3-alpha-Hydroxysteroid Dehydrogenase (B-Specific)
D002352:Carrier Proteins; D018076:DNA, Complementary; D006913:Hydroxysteroid Dehydrogenases; D008562:Membrane Glycoproteins; D010088:Oxidoreductases; C037643:bile acid binding proteins; C435496:AKR1C2 protein, human; D045002:3-alpha-Hydroxysteroid Dehydrogenase (B-Specific); C048338:trans-1,2-dihydrobenzene-1,2-diol dehydrogenase