Cylic nucleotide phosphodiesterase in silkworm. Characterization of cyclic GMP phosphodiesterase.
The existence of cyclic GMP phosphodiesterase (EC 3.1.4.-) was demonstrated in silkworm larva by gel filtration of the homogenate. The cyclic GMP phosphodiesterase was separated from cyclic AMP phosphodiesterases by column chromatography on hydroxyapatite and Sephadex G-200. The enzyme has a molecular weight of approx. 260 000, and optimum pH of 8.3 and a Km value of 2 muM. The enzyme is activated by 5 mM of Mg2+ and 2 mM of Mn2+. The cyclic GMP phosphodiesterase activity was greatly inhibited by low concentrations of cyclic IMP but to a lesser extent by cyclic AMP even at a high concentration. The activity was also inhibited by caffeine and theophylline.
D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000302:isolation & purification; D012831:Bombyx / Q000201:enzymology*; D002110:Caffeine / Q000494:pharmacology; D002850:Chromatography, Gel; D000242:Cyclic AMP / Q000494:pharmacology; D006152:Cyclic GMP / Q000378:metabolism; D007289:Cyclic IMP / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D008345:Manganese / Q000494:pharmacology; D008970:Molecular Weight; D009711:Nucleotides / Q000494:pharmacology; D010727:Phosphoric Diester Hydrolases / Q000302:isolation & purification / Q000378:metabolism*; D013806:Theophylline / Q000494:pharmacology
D009711:Nucleotides; D007289:Cyclic IMP; D002110:Caffeine; D008345:Manganese; D013806:Theophylline; D000242:Cyclic AMP; D010727:Phosphoric Diester Hydrolases; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D006152:Cyclic GMP; D008274:Magnesium