Polypeptide antigens

Sugane, K. and Matsuura, T. (1990) Molecular analysis of the gene encoding an antigenic polypeptide of Trichinella spiralis infective larvae. Journal of Helminthology 64, 1—8. 

Heath, D.D. and Lawrence, S.B. (1 996) Antigenic polypeptides of Echinococcus granulosus oncospheres and definition of protective molecules. Parasite Immunology 18, 347-357. 

Lanford RE, Luckow V, Kennedy RC, Dreesman GR, Notvall L, Summers MD (1989), Expression and characterization of hepatitis B virus surface antigen polypeptides in insect cells with a baculovirus expression system, J. Virol. 63 1549-1557. 

Tam and co-workers [105-107] produced related dendrons on a Merrifield resin oilowed by surface functionalization with various antigenic polypeptide sequences. comparison of molar mass, number of terminal groups, and dimensions as a function of generation for the Denkewalter dendrons is shown in Table 1. Unlike ill the other dendron examples reported, the branch cells in this system are lnsymmetrical since they are constructed from unequal branchcell-segments as iescribed in Sect. 4.3.2. 

Snake venoms a mixture of toxins produced in the venom glands (parotid gland, or salivary gland of the upper jaw) of venomous snakes (asps or hooded snakes, e.g. the cobra sea snakes vipers, e.g. puff adder, rattlesnake). They consist of highly toxic, antigenic polypeptides and proteins (which cause paralysis and death of the prey), and enzymes (which facilitate the spread of the toxins, and initiate digestion of undivided swallowed prey). The enzymes indude hya-luronidase (promotes spread of toxins), ATPase and acetylcholine esterase (paralysis), phospholipases (hemolysis), proteinases and L-amino add oxidases (tissue necrosis and blood clotting). 

This protein has now been purified, and monospecific polyclonal antibodies have been raised against it. A similar antigenic polypeptide has been found in the seeds of all 15 species of crucifer tested to date... 

Development of a peptide vaccine is derived from the identification of the immunodominant epitope of an antigen (141). A polypeptide based on the amino acid sequence of the epitope can then be synthesized. Preparation of a peptide vaccine has the advantage of allowing for large-scale production of a vaccine at relatively low cost. It also allows for selecting the appropriate T- or B-ceU epitopes to be included in the vaccine, which may be advantageous in some cases. Several vaccines based on peptide approaches, such as SPf66 (95) for malaria and an HIV-1 peptide (142) have been in clinical trials. No peptide vaccines are Hcensed as yet. 

Himdin [8001-27-2] is a polypeptide of 66 amino acids found ia the saUvary gland secretions of the leech Himdo medicinalis (45). It is a potent inhibitor of thrombin and biads to y-thrombia with a dissociation constant of 0.8 x 10 ° M to 2.0 x lO " M. Himdin forms a stable noncovalent complex with free and bound thrombin completely iadependent of AT-III. This material has now been cloned and expressed ia yeast cells (46,47). Its antigenic poteatial ia humans remains to be estabUshed. 

These predictive methods are very useful in many contexts for example, in the design of novel polypeptides for the identification of possible antigenic epitopes, in the analysis of common motifs in sequences that direct proteins into specific organelles (for instance, mitochondria), and to provide starting models for tertiary structure predictions. 

Sela, M., Synthetic antigens and recent progi ss in immunology, in Peptides. Polypeptides and Proteins. Proceedings of the Rehovot Symposium on Poly (Amino Acids), Polypeptides and Proteins, John Wiley and sons, New York, 1974, pp. 495-509... 

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