Fluorescence study of the dynamic interaction between E1(145–162) sequence of hepatitis GB virus C and liposomes

• Published in: Analytical & bioanalytical chemistry (Print) Vol. 394; no. 4; pp. 1003 - 1010
• Main Authors: Sánchez-Martín, Maria Jesús, Amigo, José Manuel, Pujol, Montserrat, Haro, Isabel, Alsina, M. Asunción, Busquets, M. Antonia
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.06.2009; Springer
• Subjects: Algorithms; Analytical Chemistry; Anisotropy; Biochemistry; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Dimyristoylphosphatidylcholine - chemistry; Diphenylhexatriene - chemistry; Exact sciences and technology; Fluorescence; Food Science; GB virus; Hepatitis; Hepatitis G virus; Laboratory Medicine; Least-Squares Analysis; Lipid Bilayers - chemistry; Membranes; Monitoring/Environmental Analysis; Multivariate Analysis; Original Paper; Peptides; Phosphatidylglycerols - chemistry; Reproducibility of Results; Spectrometric and optical methods; Spectrometry, Fluorescence; Sport utility vehicles; Surface Properties; SUV; Temperature; Trimethyl Ammonium Compounds - chemistry; Tryptophan; Unilamellar Liposomes - chemistry; Viral Envelope Proteins - chemical synthesis; Viral Envelope Proteins - chemistry; Anisotropy; Hepatitis GB virus C; Tryptophan fluorescence; MCR-ALS; Synthetic peptides; Liposomes; HGV/GBV-C; Water; Peptides; Phospholipid; Tryptophan; Lipids; Air; Multivariate analysis; Algorithm; Bilayer; Protein; Fluorescence spectrometry; Membrane
• ISSN: 1618-2642; 1618-2650
• DOI: 10.1007/s00216-008-2593-8

The physicochemical characterization of the peptide sequence E1(145–162) corresponding to the structural protein E1 of the hepatitis G virus was done by studying its interaction with model membranes. Small unilamellar vesicles (SUVs) of dimyristoylphosphatidylglycerol or dimyristoylphosphatidylcholine were chosen as mimetic membranes. Peptide incorporation and location in the phospholipid bilayer was investigated by fluorescence anisotropy with SUVs labeled with diphenylhexatriene (DPH) or trimethylammonium–DPH. The addition of the peptide E1(145–162) showed significant changes in the anisotropy values of the probe located at the air/water interface. These results indicate that the peptide E1(145–162) preferably interacts with the lipid surface without penetrating inside the bilayer. A series of fluorescence experiments based on tryptophan peptide fluorescence were modeled by means of multivariate curve resolution-alternating least squares (MCR-ALS) algorithm to further study the peptide interaction with bilayers at different temperatures. The preliminary results obtained with MCR-ALS showed how the peptide concentration decay is directly linked to the appearance of a new specie, which corresponds to the lipid-peptide binding. These results provide useful information for the design of synthetic immunopeptides that can be incorporated into a liposomal system with potential to promote a direct delivery of the membrane-incorporated immunogen to the immunocompetent cells, thus increasing the immuno response from the host.