Effect of chain length on the conformation and T cell recognition of synthetic hemagglutinin fragments.
Circular dichroism and Fourier-transform infrared spectroscopies were used to compare the conformational mobility of 13-mer peptides covering the 317-329 region of the envelope protein hemagglutinin of human influenza A virus subtypes H1, H2 and H3 with that of their truncated deca- and nonapeptide analogs. These peptides were demonstrated to bind to the murine I-Ed major histocompatibility complex encoded class II and human HLA-B*2705 class I molecules. Despite the amino acid substitutions in the three 13-mer subtype sequences, no significant differences in the conformational properties could be shown. Deletion of the N-terminal three residues resulted in a shift to an increased alpha-helical conformer population in the 317-329 H1 peptide and the breakage of the 3(10) or weakly H-bonded (nascent) alpha-helix in the H2 and H3 peptides. The conformational change observed upon deletion did not influence the efficiency of I-Ed peptide interaction, however, the C-terminal Arg had a beneficial effect both on MHC class II and class I binding without causing any remarkable change in solution conformation.
Tóth
G K
GK
Holly
S
S
Majer
Z
Z
Hollósi
M
M
Rajnavölgyi
E
E
Laczkó
I
I
D000818:Animals; D002942:Circular Dichroism; D006388:Hemagglutinins / Q000737:chemistry* / Q000276:immunology; D006801:Humans; D051379:Mice; D011487:Protein Conformation; D017550:Spectroscopy, Fourier Transform Infrared; D013601:T-Lymphocytes / Q000276:immunology*
D006388:Hemagglutinins