1t0w

From Proteopedia

Revision as of 12:12, 20 March 2008

25 NMR structures of Truncated Hevein of 32 aa (Hevein-32) complex with N,N,N-triacetylglucosamina

Overview

HEV32, a 32-residue, truncated hevein lacking eleven C-terminal amino acids, was synthesized by solid-phase methodology and correctly folded with three cysteine bridge pairs. The affinities of HEV32 for small chitin fragments--in the forms of N,N',N"-triacetylchitotriose ((GlcNAc)3) (millimolar) and N,N',N",N"',N"",N""'-hexaacetylchitohexaose ((GlcNAc)6) (micromolar)--as measured by NMR and fluorescence methods, are comparable with those of native hevein. The HEV32 ligand-binding process is enthalpy driven, while entropy opposes binding. The NMR structure of ligand-bound HEV32 in aqueous solution was determined to be highly similar to the NMR structure of ligand-bound hevein. Solvated molecular-dynamics simulations were performed in order to monitor the changes in side-chain conformation of the binding site of HEV32 and hevein upon interaction with ligands. The calculations suggest that the Trp21 side-chain orientation of HEV32 in the free form differs from that in the bound state; this agrees with fluorescence and thermodynamic data. HEV32 provides a simple molecular model for studying protein-carbohydrate interactions and for understanding the physiological relevance of small native hevein domains lacking C-terminal residues.

About this Structure

1T0W is a Single protein structure of sequence from [1]. Full crystallographic information is available from OCA.

Reference

NMR and modeling studies of protein-carbohydrate interactions: synthesis, three-dimensional structure, and recognition properties of a minimum hevein domain with binding affinity for chitooligosaccharides., Aboitiz N, Vila-Perello M, Groves P, Asensio JL, Andreu D, Canada FJ, Jimenez-Barbero J, Chembiochem. 2004 Sep 6;5(9):1245-55. PMID:15368576

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