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Stereospecificity of hydrogen transfer by the human placental 15‐hydroxy prostaglandin dehydrogenase
Author(s) -
Saintot M.,
Thaler-Dao H.,
Descomps B.,
de Paulet A.Crastes
Publication year - 1976
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(76)80977-5
Subject(s) - chemistry , humanities , philosophy
The human placenta contains a soluble 1 5S-hydroxy prostaglandin dehydrogenase (EC 1.1.1.141) which is the first enzyme involved in the catabolism of prostaglandins in the placenta [ 11. A strict stereospecificity for the 15S-hydroxy group of prostaglandin is a characteristic feature of this enzyme which accepts only NAD’ as cofactor [2]. The reverse reaction, reduction of the 15ketoprostaglandin in the presence of NADH is possible in vitro (31. This property enabled us to study the stereospecificity of hydrogen transfer by the 15 hydroxy prostaglandin dehydrogenase. When tritium is transferred by a dehydrogenase from a substrate to the carbon atom C4 of NAD’, a 4 R or 4 S configuration appears depending on the stereospeciticity of the enzyme [4]. Class A dehydrogenases lead to the 4 R configuration, class B dehydrogenases to the 4 S configuration [5]. In the present experiment, 15-keto-PGEs was incubated with the enzyme in the presence of 4 S [4-3H]NADH: only the tritium was transferred to the prostaglandin. Thus, our data give evidence that human placental prostaglandin dehydrogenase mediates hydrogen transfer from the 4-pro-S side of NADH to the substrate and should be considered as a B enzyme.