PURINE AND PYRIMIDINE DEGRADATION

BASIC STRUCTURE OF PURINES

DEGRADATION OF PURINES

ADENOSINE DEAMINASE DEFICIENCY Leads to immunodeficiency disease in which T and B lymphocytes don’t develop. Lack of ADA leads to increase in concentration of dATP- inhibitor of ribonucleotide reductase. High levels of dATP produce deficiency of other dNTPs in T lymphocytes. Victims don’t survive unless isolated in sterile bubble environment.

GOUT Disease of joints caused by elevated concentration of uric acid in blood and tissues. Inflamed, painful and arthritic joints due to deposition of sodium urate crystals. Kidneys are also affected. Predominant in males. Can be treated by drug allopurinol. Inhibits xanthine oxidase and itself gets converted to oxypurinol with the help of the enzyme.

BASIC STRUCTURE OF PYRIMIDINES

DEGRADATION OF PYRIMIDINES

The pathways for degradation of pyrimidines generally lead to production of NH4+ production which enters the urea cycle forming urea.

REGULATION OF UREA CYCLE