Evaluation of structure-antigenicity relationship of peptides from human immunodeficiency virus type 1 (HIV-1) p18 protein by circular dichroism.
The antigenicity of Human Immunodeficiency Virus type 1 (HIV-1) matrix p18 protein was evaluated by analyzing the specificity of anti-p18 antibodies elicited either in HIV-1 infected humans, or in HIV-1 infected or immunized chimpanzees, against a panel of long and short overlapping synthetic peptides [from 12 to 46 amino acid (aa) residues] covering the entire sequence of p18. The relationship between peptide structure and antigenicity was further investigated by probing the secondary structures of the peptides by circular dichroism. The results obtained clearly showed the immunodominance of the N-terminal region mimicked by peptide P1 (aa 2-45), which reacted with 52 and 100% of human and chimpanzee anti-p18 sera, respectively. In contrast smaller 15 aa long peptides C1, C2, C3, C4 and P3 which cover the entire sequence of immunodominant peptide P1, showed only weak or no reactivity. In contrast to widely accepted hypotheses, circular dichroism analysis of both small and large peptides secondary structures did not show any obvious correlation between antigenicity and the ability of peptides to adopt an ordered conformation.
Mabrouk
K
K
Laboratoire de Biochimie CNRS URA 1455, Faculté de Médecine Nord, Marseille, France.
Moulard
M
M
Gluckman
J C
JC
Romi
R
R
Rochat
H
H
Van Rietschoten
J
J
Bahraoui
E
E
D016915:AIDS Vaccines / Q000276:immunology; D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D002942:Circular Dichroism; D004797:Enzyme-Linked Immunosorbent Assay; D015683:Gene Products, gag / Q000737:chemistry* / Q000276:immunology*; D015483:HIV Antibodies / Q000276:immunology; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D008969:Molecular Sequence Data; D002679:Pan troglodytes; D011498:Protein Precursors / Q000276:immunology; D017433:Protein Structure, Secondary; D013329:Structure-Activity Relationship; D054301:gag Gene Products, Human Immunodeficiency Virus
D016915:AIDS Vaccines; D000911:Antibodies, Monoclonal; D015683:Gene Products, gag; D015483:HIV Antibodies; D007106:Immune Sera; D011498:Protein Precursors; D054301:gag Gene Products, Human Immunodeficiency Virus; C061169:p18 gag protein, Human immunodeficiency virus 1; C059767:p55 gag precursor protein, Human immunodeficiency virus 1