1979/05/01 by Bruce Martin, Frederick S. Richardson, F. S. Richardson · 2 citations
Materials Science · Chemistry · #Lanthanide and Transition Metal Complexes #Molecular Sensors and Ion Detection #Electrochemical Analysis and Applications
paper · doi:10.1017/s0033583500002754
Calcium ion plays an essential role in many biological processes. The environment about Ca 2+ may be probed by substitution of tripositive lanthanide ions, Ln 3+ . Ca 2+ proteins fall into two broad classes: those that are inhibited by Ln 3+ substitution and those that are not. It is suggested that although Ca 2+ undertakes a primarily structural role in the Ln 3+ non-inhibited proteins, Ca 2+ may be near the active site or participate in the mechanism of action of Ln 3+ inhibited proteins. Ca 2+ and Ln 3+ radii are similar; most Ln 3+ are slightly larger than Ca 2+ in complexes of the same coordination number, and substitution of Ln 3+ for Ca 2+ is accommodated by a slight decrease in bond distance or by an increase in coordination number. Luminescence from Tb 3+ has been demonstrated to be a sensitive environmental probe of Ca 2+ binding sites in proteins.