title: [Design and structural and thermodynamic studies of a chimeric protein derived from spectrin SH3-domain].
abstract: A number of chimerical constructions based on the spectrin SH3 domain were designed for structural and thermodynamic studies of protein folding and protein-ligand interactions. SH3 domains were found in many regulatory proteins and operate through weak interactions with proline-rich fragments of the partners. The recombinant protein studied in this work (WT-CIIA) was constructed by linking the peptide PPPVPPYSAG to the domain C-terminal trough a long 12-residue linker with the aim to achieve stable ligand binding in orientation II, which until now has not been considered as typical for spectrin domain. A comparison of fluorescence spectra of the chimerical protein and the parent domain suggests that the ligand sticks to the conservative binding site. The analysis of the urea-induced unfolding curves revealed, however, that the protein-ligand contact is not stable enough and as a result the chimerical protein structure unfolds in two steps. In order to clarify the structural aspects of the protein-ligand interaction, WT-CIIA was crystallized and a set of the X-ray diffraction data at 1.75 angstroms resolution was acquired. Preliminary analysis of the diffraction data indicated that the crystals belong to the space group P32, with unit-cell parameters a = b = 3639, c = = 112.17 angstroms, alpha = beta = 90.0, gamma = 120.0.
authors: L V
authors: LV
authors: Gushchina
authors: A G
authors: AG
authors: Gabdulkhakov
authors: V V
authors: VV
authors: Filimonov
mesh_terms: D018360:Crystallography, X-Ray; D008958:Models, Molecular; D055232:Proline-Rich Protein Domains; D011993:Recombinant Fusion Proteins / Q000737:chemistry*; D013049:Spectrin / Q000737:chemistry*; D013816:Thermodynamics; D018909:src Homology Domains
chemical_list: D011993:Recombinant Fusion Proteins; D013049:Spectrin