ABSTRACT
The hepatitis B core antigen (HBcAg) was used to present the HIV epitopes and mimics selected by phage display. The HIV epitopes were inserted into the el loop of HBcAg. The influence of insertions on the ability of chimeric HBcAg to assemble itself was studied. Special soft was made use of to detect the regularities between certain physical-and-chemical properties of amine-acid residua (belonging to an inserted alien peptide) and the presence or loss of the ability of HBcAg to assemble itself. Recommendations are provided of how to overcome difficulties related with the presentation of alien epitopes.
Subject(s)
Epitopes/immunology , HIV-1/immunology , HIV-2/immunology , Hepatitis B Core Antigens/chemistry , Hepatitis B Core Antigens/immunology , Recombinant Fusion Proteins/biosynthesis , Amino Acid Sequence , Antibodies, Viral/biosynthesis , Drug Delivery Systems , HIV Infections/immunology , HIV Infections/prevention & control , HIV Infections/virology , Hepatitis B Core Antigens/metabolism , Humans , Protein Folding , Protein Structure, Secondary , Protein Structure, Tertiary , Recombinant Fusion Proteins/chemistry , Recombinant Fusion Proteins/metabolism , Sequence Analysis, Protein , Vaccines, Synthetic , Viral VaccinesABSTRACT
Peptides binding, in vivo, with mouse lung adenocarcinoma, were selected from a peptide phage library containing above 100 million of different permutations. The selected phages carrying specific peptides accumulated in the tumor node, after intravenous injections made in A/Sn mice with induced adenocarcinoma, and persisted there even in 24 h after injections; whereas, they were detected in small quantities or not detected at all in other tissues (e.g. lungs and muscles). The selected bacteriophages were shown to accumulate not only in the primary tumor node but also in the lung with multiple metastases. Finally, amino acid sequences of exposed peptides were defined.
Subject(s)
Adenocarcinoma/metabolism , Lung Neoplasms/metabolism , Peptide Library , Peptides/metabolism , Animals , Bacteriophages/metabolism , Injections, Intravenous , Ligands , Male , Mice , Mice, Inbred Strains , Neoplasm Metastasis , Neoplasm Transplantation , Neoplasms, Experimental , Protein Binding , Time FactorsABSTRACT
Phages that expose peptides specifically interacting with glycyrrhizic acid (GA) were selected from a phage peptide library by affinity selection and ELISA. Amino acid sequence analysis of the selected peptides and human proteins with the SIM program revealed homology to tyrosine protein kinases, serine/threonine protein kinases, tyrosine phosphatases, and some receptors. Analysis of the peptide and virus protein sequences with the BLAST program showed that GA has affinity for various surface proteins of several human viruses such as HIV-1, hepatitis C virus, and herpesviruses.
Subject(s)
Bacteriophages/metabolism , Glycyrrhizic Acid/metabolism , Peptide Library , Anti-HIV Agents/pharmacology , Base Sequence , Binding Sites , DNA Primers , Enzyme-Linked Immunosorbent Assay , Glycyrrhizic Acid/pharmacology , HIV-1/metabolism , Hepacivirus/metabolism , Herpesviridae/metabolismABSTRACT
Phage display was used to obtain peptides mimicking a HIV-1 gp41 conserved epitope recognized by virus-neutralizing monoclonal antibodies (MCA) 2F5. Rabbits and mice were immunized with the peptides exposed on the surface of filamentous bacteriophages. Antibodies to gp41 were detected in the sera of immunized animals. The virus-neutralizing activity of the sera was examined.
Subject(s)
Antibodies, Monoclonal/immunology , Epitopes/immunology , HIV Envelope Protein gp41/immunology , HIV-1/immunology , Molecular Mimicry/immunology , Peptides/immunology , Amino Acid Sequence , Animals , Bacteriophages/immunology , Epitopes/chemistry , Female , Immune Sera , Immunization , Mice , Mice, Inbred C57BL , Molecular Sequence Data , Peptides/chemistry , RabbitsABSTRACT
A phage peptide library was used to select peptides interacting with virus-neutralizing monoclonal antibodies (mAb) 2G12 which recognize a discontinuous surface epitope of HIV-1 gp120. With the published X-ray data, gp120 regions involved in the antigenic determinant were predicted. Binding with mAb 2G12 was ascribed to Trh-297, Phe-383, Tyr-384, Arg-419, Ile-420, Thr-415, Leu-416, Pro-417, Lys-421, and Trp-112. Though distant in the gp120 sequence, these residues are close in space and form the 2G12 epitope on the gp120 surface.
Subject(s)
Antibodies, Monoclonal , Epitopes/immunology , HIV Envelope Protein gp120/immunology , Amino Acid Sequence , Antibody Affinity , Binding Sites , Epitopes/metabolism , HIV Envelope Protein gp120/chemistry , Molecular Sequence Data , Peptide Library , Protein ConformationABSTRACT
A phase peptide library was screened with virus-neutralizing monoclonal antibodies (MCA) 2F5 which recognize a conserved epitope of HIV-1 gp41. Phages that expose peptides specifically binding with MCA 2F5 were selected by ELISA. Amino acid sequence analysis revealed a homology to region 662-671 of HIV-1 HB10 gp160 for most peptides. The major role in recognition was ascribed to Asp-664, Lys-665, and Trp-666. The epitope-mimicking peptides were tested for immunogenicity. Antibodies to gp41 were detected in serum of immunized rabbits.
