ISSN:
1432-1912
Keywords:
Key words Ecto-ATPase
;
Suramin
;
Metal cation coordination
;
ATPγS
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Ecto-nucleotidases are plasma membrane-bound enzymes that sequentially dephosphorylate extracellular nucleotides such as ATP. This breakdown of ATP and other nucleotides obscures the characterization and classification of P2 (nucleotide) receptors. We therefore studied suramin and several of its analogs, divalent cations and ATPγS for their ability to inhibit ecto-ATPase in human blood cells. Suramin itself and Ni2+ were the more potent, non-competitive inhibitors with micromolar affinity. ATPγS also displayed micromolar affinity and inhibited ecto-ATPase competitively. The data obtained with the divalent cations demonstrate that coordination of the phosphate chain but not the N7 of the adenine ring is required for the breakdown of ATP by ecto-ATPase. Divalent cations that coordinate both the phosphate chain and N7 inhibit ecto-ATPase in a non-competitive manner.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00171044
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