1ueo
From Proteopedia
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Solution structure of the [T8A]-Penaeidin-3
Overview
Penaeidins are a family of antimicrobial peptides of 47-63 residues, isolated from several species of shrimp. These peptides display a, proline-rich domain (N-terminal part) and a cysteine-rich domain, (C-terminal part) stabilized by three conserved disulfide bonds whose, arrangement has not yet been characterized. The recombinant penaeidin-3a, of Litopenaeus vannamei (63 residues) and its [T8A]-Pen-3a analogue were, produced in Saccharomyces cerevisiae and showed similar antimicrobial, activity. The solution structure of the [T8A]-Pen-3a analogue was, determined by using two-dimensional 1H NMR and simulated annealing, calculations. The proline-rich domain, spanning residues 1-28 was found to, be unconstrained. In contrast, the cysteine-rich domain, spanning residues, 29-58, displays a well defined structure, which consists of an amphipathic, helix (41-50) linked to the upstream and the downstream coils by two, disulfide bonds (Cys32-Cys47 and Cys48-Cys55). These two coils are in turn, linked together by the third disulfide bond (Cys36-Cys54). Such a, disulfide bond packing, which is in agreement with the analysis of trypsin, digests by ESI-MS, contributes to the highly hydrophobic core. Side chains, of Arg45 and Arg50, which belong to the helix, and side chains of Arg37, and Arg53, which belong to the upstream and the downstream coils, are, located in two opposite parts of this globular and compact structure. The, environment of these positively charged residues, either by hydrophobic, clusters at the surface of the cysteine-rich domain or by sequential, hydrophobic residues in the unconstrained proline-rich domain, gives rise, to the amphipathic character required for antimicrobial peptides. We, hypothesize that the antimicrobial activity of penaeidins can be explained, by a cooperative effect between the proline-rich and cysteine-rich, features simultaneously present in their sequences.
About this Structure
1UEO is a Single protein structure of sequence from Litopenaeus vannamei. Full crystallographic information is available from OCA.
Reference
Solution structure of the recombinant penaeidin-3, a shrimp antimicrobial peptide., Yang Y, Poncet J, Garnier J, Zatylny C, Bachere E, Aumelas A, J Biol Chem. 2003 Sep 19;278(38):36859-67. Epub 2003 Jul 3. PMID:12842879
Page seeded by OCA on Wed Nov 21 04:04:23 2007
