title: Screening HIV-1 antigenic peptides as receptors for antibodies and CD4 in allosteric nanosensors.
abstract: We have analyzed the suitability of six antigenic peptides from several HIV-1 structural proteins (namely gp41, gp120, p17, and p24), as anti-HIV-1 antibody receptors in an allosteric enzymatic biosensor. These peptides were inserted in a solvent-exposed surface of Escherichia coli (E. coli) beta-galactosidase by means of conventional recombinant DNA technology. The resulting enzymes were tested to allosterically respond to sera from HIV-1-infected individuals. Only stretches from gp41 and gp120 envelope proteins were able to transduce the molecular contact signal in the presence of immunoreactive sera. Intriguingly, the enzyme displaying the CD4 binding site segment KQFINMWQEVGKAMYAPP was activated by soluble CD4, suggesting that it produces conformational modifications on the allosteric enzyme as those occurring during antibody-promoted induced fit. This fact is discussed in the context of the design of smart protein drugs and markers targeted to CD4+ cells.
authors.affiliation: Departament de Matemàtica Aplicada IV, Universitat Politècnica de Catalunya, Campus Nord, Jordi Girona 1-3, 08034 Barcelona, Spain.
authors.forename: Rosa María
authors.initials: RM
authors.lastname: Ferraz
authors.forename: Escarlata
authors.initials: E
authors.lastname: Rodríguez-Carmona
authors.forename: Neus
authors.initials: N
authors.lastname: Ferrer-Miralles
authors.forename: Andreas
authors.initials: A
authors.lastname: Meyerhans
authors.forename: Antonio
authors.initials: A
authors.lastname: Villaverde
mesh_terms: D000494:Allosteric Regulation; D000595:Amino Acid Sequence; D015374:Biosensing Techniques / Q000295:instrumentation*; D015704:CD4 Antigens / Q000276:immunology*; D004789:Enzyme Activation; D015483:HIV Antibodies / Q000276:immunology*; D015488:HIV Antigens / Q000032:analysis* / Q000737:chemistry; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D008969:Molecular Sequence Data; D036103:Nanotechnology; D010455:Peptides / Q000032:analysis* / Q000737:chemistry; D011971:Receptors, Immunologic / Q000032:analysis*; D011994:Recombinant Proteins; D001616:beta-Galactosidase
chemical_list: D015704:CD4 Antigens; D015483:HIV Antibodies; D015488:HIV Antigens; D010455:Peptides; D011971:Receptors, Immunologic; D011994:Recombinant Proteins; C076613:recombinant soluble CD4; D001616:beta-Galactosidase