ALLOSTERIC MODULATION BY ATP, CALCIUM AND MAGNESIUM-IONS OF RAT OSSEOUS PLATE ALKALINE-PHOSPHATASE
Contribuinte(s) |
Universidade Estadual Paulista (UNESP) |
---|---|
Data(s) |
20/05/2014
20/05/2014
03/09/1993
|
Resumo |
Alkaline phosphatase from rat osseous plate is allosterically modulated by ATP, calcium and magnesium at pH 7.5. At pH 9.4, the hydrolysis of ATP and PNPP follows Michaelis-Menten kinetics with K0.5 values of 154 muM and 42 muM, respectively. However, at pH 7.5 both substrates exhibit more complex saturation curves, while only ATP exhibited site-site interactions. Ca2+-ATP and Mg2+-ATP were effective substrates for the enzyme, while the specific activity of the enzyme for the hydrolysis of ATP at pH 7.5 was 800-900 U/mg and was independent of the ion species. ATP, but not PNPP, was hydrolyzed slowly in the absence of metal ions with a specific activity of 140 U/mg. These data demonstrate that in vitro and at pH 7.5 rat osseous plate alkaline phosphatase is an active calcium or magnesium-activated ATPase. |
Formato |
22-28 |
Identificador |
http://dx.doi.org/10.1016/0167-4838(93)90058-Y Biochimica Et Biophysica Acta. Amsterdam: Elsevier B.V., v. 1202, n. 1, p. 22-28, 1993. 0006-3002 http://hdl.handle.net/11449/32220 10.1016/0167-4838(93)90058-Y WOS:A1993LY16100004 |
Idioma(s) |
eng |
Publicador |
Elsevier B.V. |
Relação |
Biochimica Et Biophysica Acta |
Direitos |
closedAccess |
Palavras-Chave | #ALLOSTERIC MODULATION #Alkaline phosphatase #ATPase #ENZYME KINETICS |
Tipo |
info:eu-repo/semantics/article |