Intracellular distribution of AMP deaminase in the pig thyroid gland.

AMP deaminase and adenosine deaminase activities were assayed in the subcellular fractions of pig thyroid gland. AMP deaminase is localized in the cytosolic fraction; however, this enzyme showed remarkable tendency to bind with the subcellular particulate fractions. Adenosine deaminase is also localized in the cytosolic fraction but in contradistinction to AMP deaminase, adenosine deaminase under the same experimental conditions has no tendency of binding to subcellular particulate fractions. The significance of AMP deaminase binding to subcellular particulate fractions is discussed.