1j5b
From Proteopedia
Solution structure of a hydrophobic analogue of the winter flounder antifreeze protein
Overview
The solution structure of a synthetic mutant type I antifreeze protein (AFP I) was determined in aqueous solution at pH 7.0 using nuclear magnetic resonance (NMR) spectroscopy. The mutations comprised the replacement of the four Thr residues by Val and the introduction of two additional Lys-Glu salt bridges. The antifreeze activity of this mutant peptide, VVVV2KE, has been previously shown to be similar to that of the wild type protein, HPLC6 (defined here as TTTT). The solution structure reveals an alphahelix bent in the same direction as the more bent conformer of the published crystal structure of TTTT, while the side chain chi1 rotamers of VVVV2KE are similar to those of the straighter conformer in the crystal of TTTT. The Val side chains of VVVV2KE assume the same orientations as the Thr side chains of TTTT, confirming the conservative nature of this mutation. The combined data suggest that AFP I undergoes an equilibrium between straight and bent helices in solution, combined with independent equilibria between different side chain rotamers for some of the amino acid residues. The present study presents the first complete sequence-specific resonance assignments and the first complete solution structure determination by NMR of any AFP I protein.
About this Structure
1J5B is a Single protein structure. This structure supersedes the now removed PDB entry 1k16. Full crystallographic information is available from OCA.
Reference
Solution structure of a hydrophobic analogue of the winter flounder antifreeze protein., Liepinsh E, Otting G, Harding MM, Ward LG, Mackay JP, Haymet AD, Eur J Biochem. 2002 Feb;269(4):1259-66. PMID:11856360 Page seeded by OCA on Fri May 2 20:49:32 2008
