Structural properties of the putative fusion peptide of hepatitis B virus upon interaction with phospholipids. Circular dichroism and Fourier-transform infrared spectroscopy studies.
A peptide corresponding to the N-terminal sequence of the S protein from hepatitis B virus (Met-Glu-Asn-Ile-Thr-Ser-Gly-Phe-Leu-Gly-Pro-Leu-Leu-Val-Leu-Gln) has been previously shown to interact with phospholipids and promote vesicle aggregation, phospholipid mixing, and liposome leakage, as well as erythrocyte lysis [Rodríguez-Crespo, I., Núñez, E., Gómez-Gutiérrez, J., Yélamos, B., Albar, J. P., Peterson, D. L. & Gavilanes, F. (1995) J. Gen. Virol. 76, 301-308]. The conformation of this putative fusion peptide has been studied, both at low and high peptide concentrations, by means of circular dichroism and Fourier-transform infrared spectroscopy, respectively. When the peptide is dissolved in trifluoroethanol, a significant population of alpha-helical structure is found in spite of the proline residue at position 11. In contrast, this hydrophobic oligopeptide has a high tendency to form large beta-sheet aggregates in aqueous buffers. Most of these aggregates can be eliminated by centrifugation. The peptide remaining in the supernatant adopts a non-ordered conformation. The aggregates can be dissociated by the anionic detergent sodium cholate, but the peptide still maintains an extended conformation. In the presence of acidic phospholipid vesicles, the putative fusion peptide adopts a highly stable beta-sheet conformation. Thus, unlike the fusion peptides of other viruses, an extended conformation seems to be the preferred structure when interacting with phospholipids. Such a conformation should be responsible for its membrane destabilization properties.
Rodríguez-Crespo
I
I
Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas, Universidad Complutense, Madrid, Spain.
Gómez-Gutiérrez
J
J
Encinar
J A
JA
González-Ros
J M
JM
Albar
J P
JP
Peterson
D L
DL
Gavilanes
F
F
D000595:Amino Acid Sequence; D002942:Circular Dichroism; D006515:Hepatitis B virus; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000378:metabolism; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry*; D010713:Phosphatidylcholines; D010715:Phosphatidylglycerols; D010743:Phospholipids / Q000737:chemistry / Q000378:metabolism*; D017433:Protein Structure, Secondary; D017550:Spectroscopy, Fourier Transform Infrared; D064370:Spike Glycoprotein, Coronavirus; D014759:Viral Envelope Proteins / Q000737:chemistry* / Q000378:metabolism; D014760:Viral Fusion Proteins / Q000737:chemistry* / Q000378:metabolism
D008562:Membrane Glycoproteins; D010446:Peptide Fragments; D010713:Phosphatidylcholines; D010715:Phosphatidylglycerols; D010743:Phospholipids; D064370:Spike Glycoprotein, Coronavirus; D014759:Viral Envelope Proteins; D014760:Viral Fusion Proteins; C578557:spike glycoprotein, SARS-CoV; C578553:spike protein, mouse hepatitis virus; C002773:dimyristoylphosphatidylglycerol