Protein antigens determinants

Hopp TP, Woods KR. (1981) Prediction of protein antigenic determinants from amino acid sequences. Proc Natl Acad Sci U S A78, 3824-8. 

Barlow DJ, Edwards MS, Thornton JM. Continuous and discontinuous protein antigenic determinants. Nature. 1986 322 747. 

From more detailed studies using several proteins, antigenic determinants appear to generally consist of structural elements involving 6-7 amino acid side chains (Atassi, 1975 Atassi and Stavitsky, 1977). Antigenic determinants... 

In some cases, the anionic POs adsorbed on chitin have similar antigenic determinants, but the plants belonging to different families - and even members of the same family - could have polysaccharide-specific POs with different structures. Thus, the majority of investigated species had anionic chitin-specific peroxidises, and these isoforms from potato Solcmaceae) and horseradish Brassicaceae) formed lines of precipitation with antibodies to wheat chitin-bound PO but not to anionic isoPO (Maksimov et al., 2000). However, protein extracts from several plants of Brassicaceae, Cucurhitaceae and Fahaceae formed precipitate with both the chitin-specific and anionic PO of wheat (Fig. 3). It was foimd that the greatest homology showed in plants and formed precipitation lines with the anionic PO of wheat (Tab. 2). 

The most frequent application of SPOT-synthesis has been in the preparation of peptide arrays for the identification of linear B-cell epitopes. If the protein antigen is known, a set of overlapping peptides that encompass the entire sequence can be readily synthesized and assayed for binding of antibody (Reineke et al., 1999). The individual residues critical for binding can then be determined by SPOT-synthesis of peptides containing amino acid substitutions. 

Van Regenmortel, M. H. V. andPellequer.J. L. (1994), Predicting antigenic determinants in proteins looking for unidimensional solutions to a three-dimensional problem Peptide Res., 7, 224 - 228. 

Several plant vims coat proteins, including those of TMV, CPMV, AlMV and Tomato bushy stunt vims (TBSV), have been used to produce and deliver antigenic determinants from a variety of viral and bacterial pathogens. These data have been summarized in numerous publications and several reviews [12,13]. The ease of virus purification coupled with enhanced peptide immunogenicity when fused to carrier molecules makes this approach very attractive for vaccine development. 

The production of MAbs offers investigators a homogenous collection of antibodies that could bind selectively to a specific antigenic determinant with the same affinity. In addition to protein isolation and diagnostic techniques, MAbs have contributed greatly to RIAs. 

Epitope is an antigenic determinant (a part of a molecule to which an antibody binds), which is a biological structure or sequence, such as a protein or carbohydrate, that is recognized by the immune system and to which an antibody binds. 

Penicillins and cephalosporins bind irreversibly to serum albumin. It has been shown that drug-protein conjugates result from the aminolysis of the /3-lactam bond by the e-amino group of lysine residues in the protein (Fig. 5.1, Pathway e). The bound penicilloyl group appears to be the major antigenic determinant of penicillin allergy [145-148],... 

An IgG-antibody against an individual ribosomal protein binds specifically only to this protein in a ribosomal subunit. Since the antibody is divalent it can form a bridge between the identical proteins in two subunits, leading to a dimer that can be examined under Ae electron microscope. The location of the bound antibody on the subunit surface can be determined, defining the position of the antigenic determinant of a particular protein. The method relies on the fact that IgG-antibodies are able to react with specific proteins within the intact ribosomal subunits and that both subunits have discernible shapes with recognizable morphological landmarks. 

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