Crystallization of a synthetic analog of calcium-binding site III of rabbit skeletal troponin C

Single crystals of the calcium-binding peptide AcA98STnC (90–123)amide, which is a synthetic fragment analog of rabbit skeletal troponin C calcium-binding site III, have been grown in the tetragonal crystal system. Crystals were developed to a maximum size of 0.60 × 0.60 × 0.75-mm by the technique of washing and reseeding. The space group is I41 with a = 40.21(1) Å, c = 34.07(1) Å; there is 1 polypeptide fragment/crystallographic asymmetric unit, and the solvent content is estimated to be 29%. The crystals diffract to at least 1.8-Å d spacings and are stable in the x-ray beam for 1 week.