2POA image
Entry Detail
PDB ID:
2POA
Title:
Schistosoma mansoni Sm14 Fatty Acid-Binding Protein: improvement of protein stability by substitution of the single Cys62 residue
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2007-04-26
Release Date:
2008-06-10
Method Details:
Experimental Method:
Conformers Calculated:
40
Conformers Submitted:
17
Selection Criteria:
target function
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:14 kDa fatty acid-binding protein
Mutations:C62V
Chain IDs:A
Chain Length:133
Number of Molecules:1
Biological Source:Schistosoma mansoni
Ligand Molecules
Primary Citation
Stability improvement of the fatty acid binding protein Sm14 from S. mansoni by Cys replacement: Structural and functional characterization of a vaccine candidate.
Biochim.Biophys.Acta 1794 655 662 (2009)
PMID: 19150418 DOI: 10.1016/j.bbapap.2008.12.010

Abstact

The Schistosoma mansoni fatty acid binding protein (FABP), Sm14, is a vaccine candidate against, S. mansoni and F. hepatica. Previously, we demonstrated the importance of a correct fold to achieve protection in immunized animals after cercariae challenge [[10]. C.R.R. Ramos, R.C.R. Figueredo, T.A. Pertinhez, M.M. Vilar, A.L.T.O. Nascimento, M. Tendler, I. Raw, A. Spisni, P.L. Ho, Gene structure and M20T polymorphism of the Schistosoma mansoni Sm14 fatty acid-binding protein: structural, functional and immunoprotection analysis. J. Biol. Chem. 278 (2003) 12745-12751.]. Here we show that the reduction of vaccine efficacy over time is due to protein dimerization and subsequent aggregation. We produced the mutants Sm14-M20(C62S) and Sm14-M20(C62V) that, as expected, did not dimerize in SDS-PAGE. Molecular dynamics calculations and unfolding experiments highlighted a higher structural stability of these mutants with respect to the wild-type. In addition, we found that the mutated proteins, after thermal denaturation, refolded to their active native molecular architecture as proved by the recovery of the fatty acid binding ability. Sm14-M20(C62V) turned out to be the more stable form over time, providing the basis to determine the first 3D solution structure of a Sm14 protein in its apo-form. Overall, Sm14-M20(C62V) possesses an improved structural stability over time, an essential feature to preserve its immunization capability and, in experimentally immunized animals, it exhibits a protection effect against S. mansoni cercariae infections comparable to the one obtained with the wild-type protein. These facts indicate this protein as a good lead molecule for large-scale production and for developing an effective Sm14 based anti-helminthes vaccine.

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Primary Citation of related structures