MT L1 Antimetabolites - Purine "antagonists" Flashcards
1
Q
Name 3 purine antagonists
A
6 mercaptopurine
6 thioguanine
Tiazofurin
2
Q
Pathway of activation of 6MP and 6TG
A
6MP to thio-IMP (via HPRT)
or
6TG to thio-TG (via HPRT)
thio-TG to
thioGTP to TG-RNA
or
thiodGTP ti TG-DNA
3
Q
What does the enzyme HPRT stand for
A
hypoxanthinine phosphoribosyltransferase
4
Q
How is tiazofurin activated?
A
convertid to TAD
5
Q
how does tiazofurin work?
A
metabolite TAD binds at NAD+ binding site of IMPDH (NAD+ is usually used to oxidise the carboyl)
6
Q
how do thio-IMP and thio-GMP work?
A
Thio-IMP inhibits adenylosuccinate synthetase (in the pathway to ATP) and IMPDH by binding at the purine-binding site
Thio-GMP inhibits only the latter.
7
Q
What does IMPDH stand for
A
IMP dehydrogenase
