1qdd
From Proteopedia
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CRYSTAL STRUCTURE OF HUMAN LITHOSTATHINE TO 1.3 A RESOLUTION
Overview
Pancreatic juice is supersaturated with calcium carbonate. Calcite, crystals therefore may occur, obstruct pancreatic ducts, and finally cause, a lithiasis. Human lithostathine, a protein synthesized by the pancreas, inhibits the growth of calcite crystals by inducing a habit modification:, the rhombohedral (10 14) usual habit is transformed into a needle-like, habit through the (11 0) crystal form. A similar observation was made with, the N-terminal undecapeptide (pE(1)R(11)) of lithostathine. We therefore, aimed at discovering how peptides inhibit calcium salt crystal growth. We, solved the complete x-ray structure of lithostathine, including the, flexible N-terminal domain, at 1.3 A. Docking studies of pE(1)R(11) with, the (10 14) and (11 0) faces through molecular dynamics simulation, resulted in three successive steps. First, the undecapeptide progressively, unfolded as it approached the calcite surface. Second, mobile lateral, chains of amino acids made hydrogen bonds with the calcite surface. Last, electrostatic bonds between calcium ions and peptide bonds stabilized and, anchored pE(1)R(11) on the crystal surface. pE(1)R(11)-calcite interaction, was stronger with the (11 0) face than with the (10 14) face, confirming, earlier experimental observations. Energy contributions showed that the, peptide backbone governed the binding more than did the lateral chains., The ability of peptides to inhibit crystal growth is therefore essentially, based on backbone flexibility.
About this Structure
1QDD is a Single protein structure of sequence from Homo sapiens with SIA as ligand. Full crystallographic information is available from OCA.
Reference
Mechanism of calcite crystal growth inhibition by the N-terminal undecapeptide of lithostathine., Gerbaud V, Pignol D, Loret E, Bertrand JA, Berland Y, Fontecilla-Camps JC, Canselier JP, Gabas N, Verdier JM, J Biol Chem. 2000 Jan 14;275(2):1057-64. PMID:10625646
Page seeded by OCA on Wed Nov 21 00:35:49 2007
