Biomaterial Database

Mimicking of discontinuous epitopes by phage-displayed peptides, I. Epitope mapping of human H ferritin using a phage library of constrained peptides. 1993

A Luzzago, and F Felici, and A Tramontano, and A Pessi, and R Cortese

Istituto di Ricerche di Biologia Molecolare P. Angeletti, Pomezia, Rome, Italy.

We have constructed a random nonapeptide library in the N-terminal region of the major coat protein VIII of bacteriophage f1, with two cysteines flanking the insert, and preliminary data suggest that many of the clones display at least some of their peptides in cyclized form. This library was used to select oligopeptides binding to the monoclonal antibody (mAb) H107, recognising the assembled native conformation of recombinant human H-subunit ferritin (H Fer), whose three-dimensional structure is known. Comparison of the selected oligopeptides with one another allowed us to derive two consensus sequences characterized by conserved amino acid (aa) residues. Analysis of the distribution of the aa side chains exposed on the surface of H Fer reveals that most of the aa defining both consensus sequences are present either at the end of the big loop or at the end of the A helix. These two regions of the H Fer, though separated in the linear sequence, are very close in the folded molecule. Interestingly, each consensus sequence derived from the selected phage-displayed peptides is characterized by aa present both at the end of the big loop and at the end of the A helix. These two H Fer regions are good candidates for mimicry by the selected peptides and therefore for constituting part of the H107 epitope. To provide support to this hypothesis, we constructed several H Fer mutants carrying point mutations in different positions of these two regions.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D008958	Models, Molecular	Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.	Molecular Models,Model, Molecular,Molecular Model
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D009838	Oligodeoxyribonucleotides	A group of deoxyribonucleotides (up to 12) in which the phosphate residues of each deoxyribonucleotide act as bridges in forming diester linkages between the deoxyribose moieties.	Oligodeoxynucleotide,Oligodeoxyribonucleotide,Oligodeoxynucleotides
D009842	Oligopeptides	Peptides composed of between two and twelve amino acids.	Oligopeptide
D002213	Capsid	The outer protein protective shell of a virus, which protects the viral nucleic acid. Capsids are composed of repeating units (capsomers or capsomeres) of CAPSID PROTEINS which when assembled together form either an icosahedral or helical shape.	Procapsid,Prohead,Capsids,Procapsids,Proheads
D003090	Coliphages	Viruses whose host is Escherichia coli.	Escherichia coli Phages,Coliphage,Escherichia coli Phage,Phage, Escherichia coli,Phages, Escherichia coli
D005293	Ferritins	Iron-containing proteins that are widely distributed in animals, plants, and microorganisms. Their major function is to store IRON in a nontoxic bioavailable form. Each ferritin molecule consists of ferric iron in a hollow protein shell (APOFERRITINS) made of 24 subunits of various sequences depending on the species and tissue types.	Basic Isoferritin,Ferritin,Isoferritin,Isoferritin, Basic
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D000911	Antibodies, Monoclonal	Antibodies produced by a single clone of cells.	Monoclonal Antibodies,Monoclonal Antibody,Antibody, Monoclonal