Abstract
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.
Copyright 2001 Academic Press.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Adenosine Diphosphate / metabolism*
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Adenosine Triphosphatases*
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Adenosine Triphosphate / metabolism*
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Amino Acid Sequence
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Animals
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Antigens, CD / isolation & purification
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Antigens, CD / metabolism
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Apyrase / metabolism*
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Electrophoresis, Polyacrylamide Gel
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Hydrolysis
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Insecta
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Molecular Sequence Data
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Recombinant Proteins / isolation & purification
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Recombinant Proteins / metabolism
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Solubility
Substances
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Antigens, CD
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Recombinant Proteins
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Adenosine Diphosphate
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Adenosine Triphosphate
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Adenosine Triphosphatases
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Apyrase
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CD39 antigen