The regulation of 17, 20 lyase activity
P450c17 is a single microsomal enzyme that catalyzes two distinct steroid biosynthetic
activities: 17α-hydroxylase and 17, 20 lyase. Human beings have only one gene that
encodes only one form of P450c17. Three clinical observations indicated that these were
independently regulated activities. First, several cases of isolated 17, 20 lyase deficiency
were reported, in which 17α-hydroxylase activity was spared. Second, most adrenal
steroidogenesis in children stops after 17α-hydroxylation, thus permitting the synthesis of …
activities: 17α-hydroxylase and 17, 20 lyase. Human beings have only one gene that
encodes only one form of P450c17. Three clinical observations indicated that these were
independently regulated activities. First, several cases of isolated 17, 20 lyase deficiency
were reported, in which 17α-hydroxylase activity was spared. Second, most adrenal
steroidogenesis in children stops after 17α-hydroxylation, thus permitting the synthesis of …