AMP deaminase from dogfish erythrocytes: purification and some properties

The AMP deaminase from erythrocytes from the dogfish, Scyliorhinus caniculus, L., was purified by chromatography on cellulose-phosphate and DEAE-cellulose. The 1300-fold purified enzyme was highly unstable. At low substrate concentrations, a sharp pH optimum was found at pH 6.7. At higher substrate concentrations, the highest activity was found between pH 6.8 and 7.2. The substrate saturation curve was hyperbolic in the presence of monovalent cations. The binding of inorganic phosphate showed cooperativity. Overall the kinetic properties of AMP deaminase from erythrocytes from dogfish are very similar to that described for other species.