Gary S. Shaw

Metal ion binding by proteins: Current Opinion in Structural Biology 1992, 2:57…-60

Abstract The structural importance of metal ion binding to proteins has recently been studied using site-specific mutagenesis and synthetic peptide techniques. Metal binding to synthetic peptides with sequences corresponding to helix-loop-helix calcium-binding sites and ‘zinc fingers’ induces unstructured peptides to fold into structures similar to domains observed in native proteins.

Calcium-Induced Folding of Troponin-C: Formation of Homodimeric and Heterodimeric Two-Site Domains From Synthetic Peptides

Publisher Summary One approach to study the calcium-induced conformational change in troponin-C (TnC) is to utilize synthetic peptides that encompass a single helix-loop-helix calciumbinding site. By altering the amino acid composition of the peptides synthetically, the importance of the site–site interactions that occur at the peptide–peptide interface can be determined and utilized for the design of a synthetic calcium-binding protein with modified calcium affinity. To accomplish this, initial studies of the site III TnC peptide (SCIII) was expanded to incorporate calcium binding to a mixture of SOU and a 34-residue peptide representing site IV of TnC (SCIV). It is shown that calcium binding to this peptide mixture induces a conformational change in both peptides and a specific association to form a SCIII/SCIV heterodimer similar to the site–site association in TnC.