TY - JOUR
T1 - Ecto-ATP diphosphohydrolase (apyrase) in ovarian follicle cells of starfish Asterina pectinifera
AU - Mita, Masatoshi
AU - Yoshikuni, Michiyasu
AU - Nagahama, Yoshitaka
N1 - Funding Information:
The authors are grateful to Dr Yasumasu, Waseda University, for his encouragement and valuable advice. Thanks are also extended to Dr Tousuji, Kagoshima University, Dr Kiyomoto and the staff of Tateyama Marine Laboratory, Ochanomizu University, and Dr Katow and the staff of Asamushi Marine Biological Station, Tohoku University, for their kind help in collecting starfish. This study was carried out under the auspices of the NIBB Cooperative Research Program (97-120) and supported in part by a Grant-in-Aid (No. 09640797 to M.M.) from the Ministry of Education, Science, Sports and Culture of Japan.
PY - 1998
Y1 - 1998
N2 - A Mg2+-dependent ecto-ATP diphosphohydrolase (ATPDase, EC 3.6.1.5) was present in starfish ovarian follicle cells. The enzyme which had an optimum pH between 6.0 and 7.5 could hydrolyze triphosphonucleosides (ATP, dATP, GTP, CTP, UTP and ITP) and diphosphonucleosides (ADP, dADP, GDP, CDP, UDP and IDP), but not monophosphonucleosides. The K(m) values for ATP and ADP were 0.17 and 0.20 mM, respectively. The ATPDase activity was insensitive to specific ATPase inhibitors, such as ouabain, vanadate and oligomycin, an adenylate kinase inhibitor, P1, P5-di-(adenosine-5')pentaphosphate, and a phosphodiesterase inhibitor, 1-isobutyl-3-methylxanthine. The activity was mostly distributed in the membrane fraction of follicle cells. It is also interesting that hydrolysis of ATP and ADP occurred upon incubation of intact cells in seawater. Among various kinds of detergents, digitonin was capable of solubilizing the enzyme from the membrane fraction. Using digitonin extract, a high-performance liquid chromatography with Superose 6 column showed that the molecular weight of ecto-ATPDase in starfish follicle cells was ~60 000. Copyright (C) 1998 Elsevier Science Inc.
AB - A Mg2+-dependent ecto-ATP diphosphohydrolase (ATPDase, EC 3.6.1.5) was present in starfish ovarian follicle cells. The enzyme which had an optimum pH between 6.0 and 7.5 could hydrolyze triphosphonucleosides (ATP, dATP, GTP, CTP, UTP and ITP) and diphosphonucleosides (ADP, dADP, GDP, CDP, UDP and IDP), but not monophosphonucleosides. The K(m) values for ATP and ADP were 0.17 and 0.20 mM, respectively. The ATPDase activity was insensitive to specific ATPase inhibitors, such as ouabain, vanadate and oligomycin, an adenylate kinase inhibitor, P1, P5-di-(adenosine-5')pentaphosphate, and a phosphodiesterase inhibitor, 1-isobutyl-3-methylxanthine. The activity was mostly distributed in the membrane fraction of follicle cells. It is also interesting that hydrolysis of ATP and ADP occurred upon incubation of intact cells in seawater. Among various kinds of detergents, digitonin was capable of solubilizing the enzyme from the membrane fraction. Using digitonin extract, a high-performance liquid chromatography with Superose 6 column showed that the molecular weight of ecto-ATPDase in starfish follicle cells was ~60 000. Copyright (C) 1998 Elsevier Science Inc.
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U2 - 10.1016/S0305-0491(98)00031-5
DO - 10.1016/S0305-0491(98)00031-5
M3 - Article
AN - SCOPUS:0031927685
SN - 0305-0491
VL - 119
SP - 577
EP - 583
JO - Comparative Biochemistry and Physiology - B Biochemistry and Molecular Biology
JF - Comparative Biochemistry and Physiology - B Biochemistry and Molecular Biology
IS - 3
ER -