Calcium-binding sites ligands

Brandes LJ, Bogdanovic RP, Cawker MD, LaBella FS (1987) Elistamine and growth interaction of antiestrogen binding site ligands with a novel histamine site that may be associated with calcium channels. Cancer Res 47(15) 4025-4031... 

Fig. 56. The calcium-binding sites from carp muscle calcium-binding protein (a) backbone of the entire E-F hand (b) detailed view of the E-F calcium-binding site, including those side chains which are Ca ligands (c) detailed view of the C-D calcium-binding site, rotated to match part b. Oxygens are shown as open circles and a-carbons as solid dots.

Fig. 7. The calcium binding sites of HRP C (detail). Ligands to the distal (A) and proximal (B) calcium atoms are shown. The O-donor ligand sets are hsted in Section IV,D.

The proximal calcium binding site is coupled to the heme group by virtue of the fact that one of its ligands, Thrl71, is adjacent to the proximal histidine residue, Hisl70 (Fig. 4). The results of site-directed mutagenesis studies at this position are awaited with interest. An illustration of the importance of both calcium sites to the structure and function of HRP C is afforded by the need to incorporate calcium as a component of in vitro folding mixtures to obtain active recombinant enzyme from solubilized inclusion bodies (64). 

Kostelansky, M. S., Betts, L., Gorkun, O. V., and Lord, S. T. (2002). 2.8 A crystal structures of recombinant fibrinogen fragment D with and without two peptide ligands GHRP binding to the b site disrupts its nearby calcium-binding site. Biochem. 41, 12124-12132. 

Figure 17 The ditneric structure ofE-cadherinECl-2 (lEDH) (a). Two polypeptide chains and their bound calcium are shown in different colors, (b) A close-up view of the calcium-binding sites. The calcium ligand residues on chain A are labeled. Several ligands are shared by different calcium ions. All calcium binding in cadherin belongs to the discontinuous site class...

Fig. 10. Structure of the synaptotagmin C2 domain showing the calcium binding site at the top and ligands for a potential calcium binding site at the bottom. (From Sutton et al. 1995 with permission.)...

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