Enzymatic sulphation of bile salts in human liver.

An enzyme catalyzing the transfer of the sulphate group from 3' -phosphoadenosine-5' -phosphosulphate to lithocholate and glycolithocholate is identified in the cytosol of human liver. The rate of sulphation was greatest with unconjugates lithocolate. Km values for lithocholate and glycolithocholate were 2 . 10(-6) and 3.3 . 10(-6) M, respectively. No enzyme activity was found in human kidney cytosol. A simple method for quantitative assay of the enzyme in percutaneous liver biopsy specimens is described.