title: Anti-peptide aptamers recognize amino acid sequence and bind a protein epitope.
abstract: In vitro selection of nucleic acid binding species (aptamers) is superficially similar to the immune response. Both processes produce biopolymers that can recognize targets with high affinity and specificity. While antibodies are known to recognize the sequence and conformation of protein surface features (epitopes), very little is known about the precise interactions between aptamers and their epitopes. Therefore, aptamers that could recognize a particular epitope, a peptide fragment of human immunodeficiency virus type I Rev, were selected from a random sequence RNA pool. Several of the selected RNAs could bind the free peptide more tightly than a natural RNA ligand, the Rev-binding element. In accord with the hypothesis that protein and nucleic acid binding cusps are functionally similar, interactions between aptamers and the peptide target could be disrupted by sequence substitutions. Moreover, the aptamers appeared to be able to bind peptides with different solution conformations, implying an induced fit mechanism for binding. Just as anti-peptide antibodies can sometimes recognize the corresponding epitope when presented in a protein, the anti-peptide aptamers were found to specifically bind to Rev.
authors: Department of Chemistry, Indiana University, Bloomington 47405, USA.
authors: W
authors: W
authors: Xu
authors: A D
authors: AD
authors: Ellington
mesh_terms: D000595:Amino Acid Sequence; D017122:Bacteriophage T4 / Q000235:genetics; D001483:Base Sequence; D001665:Binding Sites; D017931:DNA Primers; D000939:Epitopes; D015694:Gene Products, rev / Q000737:chemistry* / Q000378:metabolism*; D016370:Gene Products, rex / Q000378:metabolism; D015696:Gene Products, tat / Q000378:metabolism; D015497:HIV-1 / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010455:Peptides; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D012367:RNA, Viral / Q000737:chemistry* / Q000378:metabolism*; D054321:rev Gene Products, Human Immunodeficiency Virus; D054322:tat Gene Products, Human Immunodeficiency Virus
chemical_list: D017931:DNA Primers; D000939:Epitopes; D015694:Gene Products, rev; D016370:Gene Products, rex; D015696:Gene Products, tat; D010455:Peptides; D012367:RNA, Viral; D054321:rev Gene Products, Human Immunodeficiency Virus; D054322:tat Gene Products, Human Immunodeficiency Virus