Chen L J, Bolt R J, Admirand W H
Biochim Biophys Acta. 1977 Jan 11;480(1):219-27. doi: 10.1016/0005-2744(77)90335-7.
An enzyme system which catalyzes the transfer of sulfate group from 3'-phosphoadenosine-5'-phosphosulfate to bile salts has been identified and characterized from rat liver. The enzyme is present in the cytosol fraction of liver cells. The apparent Km value for 3'-phosphoadenosine-5'-phosphosulfate was 8 - 10(-6) M andhat for taurolithocholate was 5 - 10(-5) M. Sulfation occurred with conjugated as well as unconjugated bile salts, however, the rate of sulfation was higher with conjugated than unconjugated. The enzyme was present in rat liver and kidney, but not detectable in brain, lung, heart, spleen or intestinal mucosa. The activity is completely inhibited by p-chloromercuribenzoate indicating the enzyme requires a sulfhydryl group for activity. A molecular weight of 130 000 was estimated by gel-filtration technique and the enzyme shows an isoelectric point of 5.3.
已从大鼠肝脏中鉴定并表征了一种催化硫酸基团从3'-磷酸腺苷-5'-磷酸硫酸酯转移至胆汁盐的酶系统。该酶存在于肝细胞的胞质溶胶部分。3'-磷酸腺苷-5'-磷酸硫酸酯的表观Km值为8×10⁻⁶ M，牛磺石胆酸盐的表观Km值为5×10⁻⁵ M。结合型和非结合型胆汁盐均可发生硫酸化反应，不过，结合型胆汁盐的硫酸化速率高于非结合型。该酶存在于大鼠肝脏和肾脏中，但在脑、肺、心脏、脾脏或肠黏膜中未检测到。对氯汞苯甲酸可完全抑制该酶的活性，表明该酶的活性需要巯基。通过凝胶过滤技术估计其分子量为130000，该酶的等电点为5.3。
