AMP + H2O => IMP + NH4+ (AMPD)

Cytosolic AMP deaminase (AMPD) catalyzes the hydrolysis of AMP to yield IMP and ammonia. Three isoforms of AMPD, E, L, and M, have been identified that differ in their expression patterns in the body. All occur as tetramers and all have qualitatively the same catalytic activity, however (Bausch-Jurken et al. 1992; Mahnke-Zizelman et al. 1998).

细胞质AMP脱氨酶（AMPD）催化AMP的水解，生成肌苷酸和氨。已鉴定出三种AMPD同型异构体，即E型、L型和M型，它们在体内的表达模式存在差异。所有同型异构体均以四聚体的形式存在，且在催化活性方面具有质的相似性（Bausch-Jurken等，1992；Mahnke-Zizelman等，1998）。