The determination of the Mg2+.ATP dissociation constant by competition with Eu3+ ion using laser-induced Eu3+ ion luminescence spectroscopy

C W McNemar; W D Horrocks Jr

doi:10.1016/0003-2697(90)90007-v

The determination of the Mg2+.ATP dissociation constant by competition with Eu3+ ion using laser-induced Eu3+ ion luminescence spectroscopy

Anal Biochem. 1990 Jan;184(1):35-8. doi: 10.1016/0003-2697(90)90007-v.

Authors

C W McNemar¹, W D Horrocks Jr

Affiliation

¹ Department of Chemistry, Pennsylvania State University, University Park 16802.

PMID: 2321757
DOI: 10.1016/0003-2697(90)90007-v

Abstract

A direct spectroscopic method for the determination of the submicromolar dissociation constant of Eu3+. ATP using laser-induced Eu3+ ion luminescence spectroscopy is described. The dissociation constant of Mg2+.ATP is then determined by the competition of Mg2+ with Eu3+ for the binding of ATP. The experiments were performed in 2H2O to mitigate the significant quenching of the Eu3+ luminescence that occurs in 1H2O. Values for the effective dissociation constants of the 1:1 ATP metal ion complexes of 1.2 +/- 0.3 X 10(-7) and 2.7 +/- 0.7 X 10(-4) M are obtained for Eu3+ and Mg2+, respectively, at p2H 5.8.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Adenosine Triphosphate / metabolism*
Binding, Competitive
Europium / metabolism*
Kinetics
Lasers
Luminescent Measurements
Spectrum Analysis

Substances

Europium
Adenosine Triphosphate