Ligand binding carboxyl-carboxylate

Proteins bind Ca "" via oxygen ligands, particularly carboxylate groups and carbonyl groups of peptide bonds. This also applies to the structure illustrated here, in which a Ca "" ion is coordinated by the oxygen atoms of carboxylate and acid amide groups. 

Metal oxide colloids have been effectively coupled with multifunctional ligands containing carboxyl groups that bind to the surface of nanoparticles [46]. One can rationally design optimal photocatalysts by tailoring functional groups for selective adsorption of specific... 

Fig. 6 21 Schematic views of G-protein coupled receptors, (a) Cross-sectional view of a G-protein coupled receptor demonstrating the N terminus in the extracellular space, seven transmembrane domains and the C terminus in the cytoplasm. (b) A view of the transmembrane domains of a G-protein coupled receptor from above demonstrating how amino acid side chains can form a precise ligand-binding site. In this example the ligand-binding site is shown to be formed by a side chain carboxylate group, two side chain amino groups and three side chain hydroxyls.

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