Monitoring the positioning of short polycationic peptides in model lipid bilayers by combining hydrogen/deuterium exchange and electrospray ionization mass spectrometry

Autor(es)

de Souza, Bibiana Monson ; Palma, Mario Sergio ^[1]

Afiliação do(s) autor(es)

^[1] Sao Paulo State Univ UNESP, Inst Biosci Rio Claro, Dept Biol, Ctr Study Social Insects, Lab Struct Biol & Zooche, Rio Claro, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES; v. 1778, n. 12, p. 2797-2805, DEC 2008.
• Citações Web of Science: 12

Resumo

Electrospray ionization mass spectrometry (ESI-MS) was used to analyze the hydrogen/deuterium exchange properties of the mastoparan peptide Apoica-MP during interactions with lipid vesicle membranes. Synthetic peptide was incorporated into large unilamellar vesicles (LUVs) of L-alpha-phosphatidylcholine (PC), resulting in proteoliposomes which were then diluted with D(2)O. After quenching deuteration by the addition of formic acid the H/D exchange was directly analyzed by ESI-MS. This strategy was used to investigate the architecture of the peptide in the membranes of PC LUVs. The deuterated peptide ions were analyzed under collision-induced dissociation (CID) mass spectrometry, which permitted the location of deuterons at the amide sites along the peptide backbone. Intramolecular hydrogen scrambling was investigated both in the free peptide and in its proteoliposome form. Some scrambling was observed for the free peptide; however, almost no scrambling occurred in the amide hydrogens of the peptide backbone embedded in the membrane. The CID spectra suggest that the N-terminal moiety of the peptide lies on the polar side of the lipid membrane, while the C-terminal region is embedded in the membrane. The protocol described here may be reliably applied to investigate the interaction of mastoparans with bilayer lipid systems. (c) 2008 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 06/04663-0 - Desenvolvimento racional de peptideos antibioticos a partir de modelos naturais encontrados na fauna de vespas sociais da biodiversidade brasileira.
• Beneficiário: Bibiana Monson de Souza
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 04/07942-2 - A bioprospecção da fauna de artrópodes do estado de São Paulo pela procura de compostos-líderes para o desenvolvimento racional de novos fármacos e pesticidas seletivos
• Beneficiário: Mario Sergio Palma
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOTA - Regular