Possible protective role of pregnenolone-16 alpha-carbonitrile in lithocholic acid-induced hepatotoxicity through enhanced hepatic lipogenesis.

Lithocholic acid (LCA) feeding causes both liver parenchymal and cholestatic damages in experimental animals. Although pregnenolone-16 alpha-carbonitrile (PCN)-mediated protection against LCA-induced hepatocyte injury may be explained by induction of drug metabolizing enzymes, the protection from the delayed cholestasis remains incompletely understood. Thus, the PCN-mediated protective mechanism has been studied from the point of modification of lipid metabolism.

Comparison of enzymatic and antifungal properties between family 18 and 19 chitinases from S. coelicolor A3(2).

Streptomyces coelicolor A3(2) has 13 chitinase genes encoding 11 family 18 and two family 19 chitinases. To compare enzymatic properties of family 19 chitinase and family 18 chitinases produced by the same organism, the four chitinases (Chi18bA, Chi18aC, Chi18aD, and Chi19F), whose genes are expressed at high levels in the presence of chitin, were produced in Escherichia coli and purified. The effect of pH on the hydrolytic activity was very different not only among the four chitinases but also among the substrates.