1pak
NMR SOLUTION STRUCTURE AND FLEXIBILITY OF A PEPTIDE ANTIGEN REPRESENTING THE RECEPTOR BINDING DOMAIN OF PSEUDOMONAS AERUGINOSA
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OverviewOverview
A synthetic peptide antigen corresponding to the C-terminus of Pseudomonas, aeruginosa K strain pilin has been studied by one and two-dimensional NMR, techniques. This peptide exists in two isomeric forms which arise as a, result of the I138-P139 amide bond. An ensemble of solution conformations, for the trans form of this 17-residue disulfide-bridged peptide (PAK, 128-144) has been generated using a simulated annealing procedure in, conjunction with distance and torsion angle restraints derived from NMR, data. One major class of backbone conformations has been identified for, this potential synthetic vaccine and indicates the presence of two, beta-turns in the region 134-142. The region that has been established as, the epitope for the monoclonal antibody PK99H is consistent with the, region of the major conformers that exhibit the most definition in the, ensemble (134-140) and also includes a type I beta-turn from residues 134, to 137. The generated structures are also consistent with observed NOEs, characteristic of beta-turns and amide proton temperature coefficient, data, which indicate the presence of two turns between residues 134 and, 142. The presence of secondary structure within the epitope substantiates, the theory that immunogenic regions of proteins are those which contain, surface-exposed structural elements such as beta-turns. Further, implications of the structure on antigenicity and cross-reactivity are, discussed.
About this StructureAbout this Structure
1PAK is a Single protein structure of sequence from Pseudomonas aeruginosa with OH and ACE as ligands. Full crystallographic information is available from OCA.
ReferenceReference
NMR solution structure and flexibility of a peptide antigen representing the receptor binding domain of Pseudomonas aeruginosa., McInnes C, Sonnichsen FD, Kay CM, Hodges RS, Sykes BD, Biochemistry. 1993 Dec 14;32(49):13432-40. PMID:8257679
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