Thread:Cholesterol to 7 dehydrocholesterol (1)
From WikiPathways
The highlighted comment was created in this revision.
There have been no changes to this discussion for at least 30 days. If it is concluded, you may want to write a summary.
Could someone please help me (clinician). Is there a pathway from Cholesterol back to 7 dehydrocholesterol in man? Some lecture books in chemistry seem to suggest so but I can't find this in the literature.
Hi SuEs. Well, the enzyme that performs the forward reaction, DHCR7, is technically capable of preforming the reverse reaction (http://enzyme.expasy.org/EC/1.3.1.21), but not under physiological conditions where [NADPH] out numbers [NADP+] by at least 100:1 (http://www.biochemj.org/content/115/4/609). There is literature on the downregulation of DHCR7 in response to high levels of cholesterol, leading to increased vitamin D production (http://www.jbc.org/content/291/16/8363.full.pdf), but I also can't find anything about biological reactions that convert cholesterol back into 7DHC. AlexanderPico 22:34, 25 May 2017 (UTC)
