Human Adenosine Deaminase (ADA) Enzyme

Background

Adenosine deaminase (ADA) is an enzyme crucial in purine metabolism, responsible for catalyzing the irreversible deamination of adenosine and deoxyadenosine to inosine and deoxyinosine, respectively. ADA is predominantly found in lymphocytes, with high activity in tissues such as the thymus, spleen, and bone marrow. It is vital for the development and maintenance of the immune system, as its deficiency leads to the accumulation of toxic purine metabolites, which impair DNA synthesis and lymphocyte survival. Mutations in the ADA gene result in severe combined immunodeficiency (SCID), characterized by a lack of functional T, B, and NK cells. ADA is also widely studied as a marker of immune activation and inflammation in conditions like tuberculosis and rheumatoid arthritis. Therapeutic interventions for ADA deficiency include enzyme replacement therapy and gene therapy, both of which aim to restore immune function.