This might look purely a naive question. But the question is attached to the existence of few enzymes inside RBC.

I know that nucleus is absent in a matured human RBC, hence no DNA inside. Nevertheless, I don't understand the role of purine metabolism and the fate of the nucleotides inside the RBC.

Coming to the core issue that I have is, currently I am looking for the possibility of presence of xanthine oxidase or aldehyde oxidase or xanthine dehydrogenase inside human RBC and the chances of formation of uric acid. Several papers found to speculate, from their studies, that human RBCs do not contain xanthine oxidase, and so far I could not find any clear evidence for the basis of formation of uric acid.

It would be great to know from the researches from the core field what is the catalyzing enzyme inside human RBC that is responsible for the uric acid production.