1. Metabolic pathways for the formation and disposal of adenine and adenosine in humans, compared with those for hypoxanthine. Adenine phosphoribosyltransferase (APRT) catalyzes the synthesis of AMP from adenine and 5-phosphoribosyl-1-pyrophosphate (PP-ribose-P) in the presence of Mg2++. In APRT deficiency, adenine is oxidized, via 8-hydroxyadenine (8-HA), to 2,8-dihydroxyadenine (2,8-DHA) by XDH. Adenine is formed, as a by-product of polyamine synthesis, from 5′-methylthioadenosine by the action of 5′-methylthioadenosine phosphorylase (MTAP). This is probably the principal route of adenine formation in vivo. A novel route of adenine formation involving S-adenosylhomocysteine hydrolase (SAHH) is indicated by the dotted line.
Source: Adenine Phosphoribosyltransferase Deficiency and 2,8-Dihydroxyadenine Lithiasis, The Online Metabolic and Molecular Bases of Inherited Disease
Citation: Valle D, Beaudet AL, Vogelstein B, Kinzler KW, Antonarakis SE, Ballabio A, Gibson K, Mitchell G. The Online Metabolic and Molecular Bases of Inherited Disease; 2014 Available at: Accessed: October 15, 2017
Copyright © 2017 McGraw-Hill Education. All rights reserved