2POA

Schistosoma mansoni Sm14 Fatty Acid-Binding Protein: improvement of protein stability by substitution of the single Cys62 residue

Summary for 2POA

• Entry DOI: 10.2210/pdb2poa/pdb
• NMR Information: BMRB: 6150
• Descriptor: 14 kDa fatty acid-binding protein (1 entity in total)
• Functional Keywords: schistosoma mansoni, fatty acid binding protein, site directed mutagenesis, protein stability, molecular dynamics, vaccine antigen, lipid binding protein
• Biological source: Schistosoma mansoni (Blood fluke)
• Total number of polymer chains: 1
• Total formula weight: 14862.77

Authors

Ramos, C.R.R.,Oyama Jr., S.,Sforca, M.L.,Pertinhez, T.A.,Ho, P.L.,Spisni, A. (deposition date: 2007-04-26, release date: 2008-06-10, Last modification date: 2024-05-15)

Primary citation

Ramos, C.R.,Spisni, A.,Oyama, S.,Sforca, M.L.,Ramos, H.R.,Vilar, M.M.,Alves, A.C.,Figueredo, R.C.,Tendler, M.,Zanchin, N.I.,Pertinhez, T.A.,Ho, P.L.
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

PubMed Abstract: 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.

PubMed: 19150418
DOI: 10.1016/j.bbapap.2008.12.010

Experimental method

SOLUTION NMR