Investigation of the conformational flexibility of DGAT1 peptides using tryptophan fluorescence

Autor(es)

Lopes, Jose L. S. ^{[1, 2]} ; Araujo, Ana P. U. ^[1] ; Jameson, David M. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Phys Sao Carlos, BR-13560 Sao Carlos, SP - Brazil

^[2] Univ Hawaii Manoa, Dept Cell & Mol Biol, Honolulu, HI 96822 - USA

• Tipo de documento: Artigo Científico
• Fonte: METHODS AND APPLICATIONS IN FLUORESCENCE; v. 3, n. 2 JUN 2015.
• Citações Web of Science: 3

Resumo

The conformational behavior of synthetic peptides corresponding to the putative binding sites of the diacylglycerol acyltransferase 1 enzyme (a polytopic integral membrane protein) was investigated using steady-state and time-resolved fluorescence spectroscopies. Three small linear peptides with 13, 15 and 22 amino acid residues, containing one, two and three Trp residues, respectively, were studied in aqueous solution, in the absence and presence of model membranes. The high flexibility and unordered conformation of the peptides in solution were confirmed by the low Trp polarization values, the high accessibility to water-soluble quencher, and the fast rotational correlation times of the Trp residues. However, upon binding to the lipid systems, the Trp residues were incorporated within the acyl hydrophobic core and their lifetimes and rotational correlation times increased. Phasor plots were employed to analyze intensity decay of peptide-lipid binding and provided a trajectory, in phasor space, that lies along a line connecting the points of the free and bound peptide. This trajectory was analyzed to determine the association constant of the peptide to the model membrane. (AU)

• Processo FAPESP: 09/17698-5 - Investigação estrutural da enzima diacilglicerol aciltransferase 1 (DGAT1) bovina e sua interação com sistemas lipídicos
• Beneficiário: Jose Luiz de Souza Lopes
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 13/20414-4 - Aplicações modernas da espectroscopia de fluorescência resolvida no tempo para investigar a ligação dos peptídios da DGAT1 em substratos lipídicos
• Beneficiário: Jose Luiz de Souza Lopes
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado
• Processo FAPESP: 10/13036-5 - Estudo da interação de peptídeos sintéticos derivados da enzima bovina diacilglicerol aciltransferase 1 (DGAT1) com modelos de membrana
• Beneficiário: Nádia de Cássia Noronha
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica