Use of the phage display technique for detection of epitopes recognized by polyclonal rabbit gliadin antibodies.

A random phage heptapeptide library was screened with rabbit antibodies against wheat flour proteins comprising gliadins and a small amount of low molecular weight glutenins (gli/glu). Gli/glu antibodies isolated from the sera selected different consensus sequences (CS). All CS contained tri- to pentapeptide stretches homologous to gli/glu sequences (proposed epitopes). In alpha- and gamma-type gliadins, these sequences are clustered in the N-terminal region recently suspected to be toxic for humans with celiac disease. Peptides with CS were synthesized and checked for reactivity. Only immune and no control rabbit sera reacted with synthetic peptides. One of eight human sera containing gliadin antibodies was reactive as well (4/8 peptides) but control sera were negative. Thus the phage display technique is useful for epitope screening of polyclonal antibodies even in the case of a group of homologous but diverse antigens

Molecular basis for the binding promiscuity of an anti-p24 (HIV- 1) monoclonal antibody

Multiple binding capabilities utilized by specific protein-to-protein interactions in molecular recognition events are being documented increasingly but remain poorly understood at the molecular level. We identified five unrelated peptides that compete with each other for binding to the paratope region of the monoclonal anti-p24 (HIV-1) antibody CB4-1 by using a synthetic positional scanning combinatorial library XXXX[B1,B2,B3,X1,X2,X3]XXXX (14 mers; 68,590 peptide mixtures in total) prepared by spot synthesis. Complete sets of substitution analogs of the five peptides revealed key interacting residues, information that led to the construction of binding supertopes derived from each peptide. These supertope sequences were identified in hundreds of heterologous proteins, and those proteins that could be obtained were shown to bind CB4-1. Implications of these findings for immune escape mechanisms and autoimmunity are discussed

Molecular basis for the binding promiscuity of an anti-p24 (HIV- 1) monoclonal antibody

Multiple binding capabilities utilized by specific protein-to-protein interactions in molecular recognition events are being documented increasingly but remain poorly understood at the molecular level. We identified five unrelated peptides that compete with each other for binding to the paratope region of the monoclonal anti-p24 (HIV-1) antibody CB4-1 by using a synthetic positional scanning combinatorial library XXXX[B1,B2,B3,X1,X2,X3]XXXX (14 mers; 68,590 peptide mixtures in total) prepared by spot synthesis. Complete sets of substitution analogs of the five peptides revealed key interacting residues, information that led to the construction of binding supertopes derived from each peptide. These supertope sequences were identified in hundreds of heterologous proteins, and those proteins that could be obtained were shown to bind CB4-1. Implications of these findings for immune escape mechanisms and autoimmunity are discussed