title: Characterization of antimalarial SPf66 peptide using MALDI-TOF MS, CD and SEC.
abstract: SPf66 is the first chemically synthesized peptide to elicit a partial protective immune response against malaria. Size-exclusion chromatography (SEC) with multi-angle laser light-scattering (MALLS) detection and hydrogen/deuterium (H/D) exchange monitored by (matrix-assisted laser desorption/ionization) MALDI-TOF (time-of-flight) mass spectrometry (MS) were used to assess the conformation and stability in aqueous solution after storage at different temperatures. Moreover, the feasible conformational changes of this peptide were also measured by circular dichroism (CD)-spectroscopy. The absolute molecular weight of SPf66 monomer and dimer species were 4765 and 8960Da using SEC with MALLS detection, and 4643 and 9490Da by MALDI-TOF MS, the discrepancy being between both methods lower than 5.7%, a value quite close to those found in other proteins. The results from H/D exchange monitored by MALDI-TOF MS and CD-spectroscopy show that the SPf66 monomer lacks ordered structure, whereas the SPf66 dimer species presents segments of secondary structure as a determined by CD measurements.
authors.affiliation: Dpto. Ingeniería Química y Tecnología Farmacéutica, Facultad de Farmacia, Universidad de La Laguna, Tenerife, Spain. amoliva@ull.es
authors.forename: Alexis
authors.initials: A
authors.lastname: Oliva
authors.forename: Maria
authors.initials: M
authors.lastname: Dorta
authors.forename: Ana
authors.initials: A
authors.lastname: Santoveña
authors.forename: Valentina
authors.initials: V
authors.lastname: Bonetto
authors.forename: Mario
authors.initials: M
authors.lastname: Salmona
authors.forename: José
authors.initials: J
authors.lastname: Fariña
mesh_terms: D002845:Chromatography; D002942:Circular Dichroism / Q000379:methods; D019281:Dimerization; D008027:Light; D017780:Malaria Vaccines / Q000737:chemistry; D010455:Peptides / Q000737:chemistry; D017433:Protein Structure, Secondary; D015800:Protozoan Proteins / Q000737:chemistry*; D011994:Recombinant Proteins; D012542:Scattering, Radiation; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods
chemical_list: D017780:Malaria Vaccines; D010455:Peptides; D015800:Protozoan Proteins; D011994:Recombinant Proteins; C066269:SPf66 protein, Plasmodium