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Benzylic alcohols as stereospecific substrates and inhibitors for aryl sulfotransferase
Author(s) -
Rao Satish I.,
Duffel Michael W.
Publication year - 1991
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/chir.530030205
Subject(s) - chemistry , stereospecificity , sulfotransferase , aryl , enantiomer , stereochemistry , sulfation , enzyme , substrate (aquarium) , organic chemistry , catalysis , biochemistry , alkyl , oceanography , geology
Aryl sulfotransferase IV catalyzes the 3′‐phosphoadenosine‐5′‐phosphosulfate (PAPS)‐dependent formation of sulfuric acid esters of benzylic alcohols. Since the benzylic carbon bearing the hydroxyl group can be asymmetric, the possibility of stereochemical control of substrate specificity of the sulfotransferase was investigated with benzylic alcohols. Benzylic alcohols of known stereochemistry were examined as potential substrates and inhibitors for the homogeneous enzyme purified from rat liver. For 1‐phenylethanol, both the (+)‐(R)‐and (−)‐(S)‐enantiomers were substrates for the enzyme, and the k cat / K m value for the (−)‐(S)‐enantiomer was twice that of the (+)‐(R)‐enantiomer. The enzyme displayed an absolute stereospecificity with ephedrine and pseudoephedrine, and with 2‐methyl‐1‐phenyl‐1‐propanol; that is, only (−)‐(1R,2S)‐ephedrine, (−)‐(1R,2R)‐pseudoephedrine, and (−)‐(S)‐2‐methyl‐1‐phenyl‐1‐propanol were substrates for the sulfotransferase. In the case of 1,2,3,4‐tetrahydro‐1‐naphthol, only the (−)‐(R)‐enantiomer was a substrate for the enzyme. Both (+)‐(R)‐2‐methyl‐1‐phenyl‐1‐propanol and (+)‐(S)‐1,2,3,4‐tetrahydro‐1‐naphthol were competitive inhibitors of the aryl sulfotransferase‐catalyzed sulfation of 1‐naphthalenemethanol. Thus, the configuration of the benzylic carbon bearing the hydroxyl group determined whether these benzylic alcohols were substrates or inhibitors of the rat hepatic aryl sulfotransferase IV. Furthermore, benzylic alcohols such as (+)‐(S)‐1,2,3,4‐tetrahydro‐1‐naphthol represent a new class of inhibitors for the aryl sulfotransferase.