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Lanthanides as probes for calcium in biological systems

Published online by Cambridge University Press:  17 March 2009

Bruce Martin  and
Frederick S. Richardson
Bruce Martin
Affiliation:
Chemistry Department, University of Virginia, Charlottesville, VA 22901
Frederick S. Richardson
Affiliation:
Chemistry Department, University of Virginia, Charlottesville, VA 22901
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Calcium ion plays an essential role in many biological processes. The environment about Ca2+ may be probed by substitution of tripositive lanthanide ions, Ln3+. Ca2+ proteins fall into two broad classes: those that are inhibited by Ln3+ substitution and those that are not. It is suggested that although Ca2+ undertakes a primarily structural role in the Ln3+ non-inhibited proteins, Ca2+ may be near the active site or participate in the mechanism of action of Ln3+ inhibited proteins. Ca2+ and Ln3+ radii are similar; most Ln3+ are slightly larger than Ca2+ in complexes of the same coordination number, and substitution of Ln3+ for Ca2+ is accommodated by a slight decrease in bond distance or by an increase in coordination number. Luminescence from Tb3+ has been demonstrated to be a sensitive environmental probe of Ca2+ binding sites in proteins.

Type
Research Article
Information
Quarterly Reviews of Biophysics , Volume 12 , Issue 2 , May 1979 , pp. 181 - 209
Copyright
Copyright © Cambridge University Press 1979

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