a synthetic metal-binding protein, contains beta-sheet scaffold & two regions corresponding to immunoglobulin hypervariable loops (H1 & H2) on to which a metal binding site was engineered; mutant H13D - His(13) replaced by Asp; mutant H13A - His(13) replaced by Ala; amino acid sequence of WT given; MB1-K3 is a more soluble form with three lysine residues added to the C-terminus
