NMR structure of rALF-Pm3, an anti-lipopolysaccharide factor from shrimp: Model of the possible lipid A-binding site. - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Biopolymers Année : 2009

NMR structure of rALF-Pm3, an anti-lipopolysaccharide factor from shrimp: Model of the possible lipid A-binding site.

Résumé

The anti-lipopolysaccharide factor ALF-Pm3 is a 98-residue protein identified in hemocytes from the black tiger shrimp Penaeus monodon. It was expressed in Pichia pastoris from the constitutive glyceraldehyde-3-phosphate dehydrogenase promoter as a folded and N-15 uniformly labeled rALF-Pm3 protein. Its 3D structure was established by NMR and consists of three alpha-helices packed against a four-stranded beta-sheet. The C-34-C-55 disulfide bond was shown to be essential for the structure stability. By using surface plasmon resonance, we demonstrated that rALF-Pm3 binds to LPS, lipid A and to OM(R)-174, a soluble analogue of lipid A. Biophysical studies of rALF-Pm3/LPS and rALF-Pm3/OM(R)-174 complexes indicated rather high molecular sized aggregates, which prevented us to experimentally determine by NMR the binding mode of these lipids to rALF-Pm3. However, on the basis of striking structural similarities to the FhuA/LPS complex, we designed an original model of the possible lipid A-binding site of ALF-Pm3. Such a binding site, located on the ALF-Pm3 beta-sheet and involving seven charged residues, is well conserved in ALF-L from Limulus polyphemus and in ALF-T from Tachypleus tridentatus. In addition, our model is in agreement with experiments showing that beta-hairpin synthetic peptides corresponding to ALF-L beta-sheet bind to LPS. Delineating lipid A-binding site of ALFs will help go further in the de novo design of new antibacterial or LPS-neutralizing drugs

Dates et versions

hal-00358510 , version 1 (03-02-2009)

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Citer

Yinshan Yang, Hélène Boze, Patrick Chemardin, André Padilla, Guy Moulin, et al.. NMR structure of rALF-Pm3, an anti-lipopolysaccharide factor from shrimp: Model of the possible lipid A-binding site.. Biopolymers, 2009, 91 (3), pp.207-20. ⟨10.1002/bip.21119⟩. ⟨hal-00358510⟩
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