Soluble apyrases release adp during ATP hydrolysis.
A soluble form of CD39 was expressed and purified from High-Five insect cells. The soluble CD39 is a monomer with a molecular weight of 54,000. The k(cat) and K(m) of the purified soluble CD39 were 4.6 s(-1) and 12 microM for ATP and 1.3 s(-1) and 7 microM for ADP as substrates, respectively. One nucleotide binding site was detected on the monomer only in the presence of Ca(2+). In contrast to the membrane bound CD39, soluble CD39 released ADP as an intermediate during ATP hydrolysis, as did the soluble potato apyrase.
Department of Molecular and Cellular Biology, Harvard University, 7 Divinity Avenue, Cambridge, Massachusetts, 02138, USA.
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D000244:Adenosine Diphosphate / Q000378:metabolism*; D000251:Adenosine Triphosphatases; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD / Q000302:isolation & purification / Q000378:metabolism; D001081:Apyrase / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D006868:Hydrolysis; D007313:Insecta; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D012995:Solubility
D015703:Antigens, CD; D011994:Recombinant Proteins; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; D001081:Apyrase; C067869:CD39 antigen