Walter R D
Tropenmed Parasitol. 1976 Sep;27(3):337-42.
3',5'-Cyclic-AMP 5'-nucleotidohydrolase (cAMP phosphodiesterase, EC 3.1.4.17) was partial purified from metacercariae of Paragonimus africanus. The enzyme activity absolutely depends on Mg2 or Mn2+. The pH-optimum of the cAMP phosphidiesterase was found at pH 8.0. The Michaelis constant for cAMP was determined to be 5 X 10(-6) M. Papaverine deoxyadenosine, theophylline and adenosine were found to be competitive inhibitors of the enzyme activity. The inhibitor constants were calculated to be 13 X 10(-6)M, 25 X 10(-5)M, and 35 X 10(-5)M, and 85 X 10(-5)M,respectively. The molecular weight of the cAMP phosphodiesterase was estimated to be about 40 000 by gel filtration.
3',5'-环磷酸腺苷5'-核苷酸水解酶（cAMP磷酸二酯酶，EC 3.1.4.17）从非洲并殖吸虫后尾蚴中部分纯化得到。该酶活性绝对依赖于Mg2+或Mn2+。发现cAMP磷酸二酯酶的最适pH值为8.0。cAMP的米氏常数测定为5×10（-6）M。发现罂粟碱、脱氧腺苷、茶碱和腺苷是该酶活性的竞争性抑制剂。抑制剂常数分别计算为13×10（-6）M、25×10（-5）M、35×10（-5）M和85×10（-5）M。通过凝胶过滤估计cAMP磷酸二酯酶的分子量约为40000。
