1. Immunogenicity of mastoparan B, a cationic tetradecapeptide isolated from the hornet (Vespa basalis) venom, and its structural requirements
- Author
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Lin Yah-Luen, Yu Hui-Ming, Ho Chewn-Lang, Chen Chiung-Tong, Chen Wan-Chen, Wang Kung-Tsung, and Hwang Ling-Ling
- Subjects
chemistry.chemical_classification ,Male ,Stereochemistry ,Immunogenicity ,Lysine ,Molecular Sequence Data ,Tryptophan ,Peptide ,Wasp Venoms ,Biology ,Toxicology ,Epitope ,Mice ,Structure-Activity Relationship ,Biochemistry ,chemistry ,Animals ,Intercellular Signaling Peptides and Proteins ,Asparagine ,Amino Acid Sequence ,Rabbits ,Leucine ,Tyrosine ,Peptides - Abstract
Mastoparan B (MP-B) is a cationic tetradecapeptide (LKLKSIVSWAKKVL-CONH2, mol. wt 1611) isolated from the black-bellied hornet (Vespa basalis) venom. The small peptide itself was capable of inducing antibodies without prior conjugation to a protein carrier in rabbits and mice. The mouse antibody was found to be of IgG1 isotype with κ-type light chain. The peptide antigen was able to form insoluble complexes with the specific antibody, suggesting that MP-B possessed more than one epitope in its molecule. The finding that MP-B was able to bind with both mouse and rabbit antibodies in sandwich ELISA supports this contention. Synthetic MP-B analogues in which lysine at position 2, 4, 11 or 12 was replaced by neutral amino acids such as asparagine or leucine showed a significant decrease in their antibody-binding activities. Substitution of lysine at position 4 (Lys4) caused the most marked inhibition in its binding activity. However, replacing tryptophan at position 9 by tyrosine caused a relatively small reduction in its binding activity. Replacing both Lys2,4 by asparagine or removing Lys-containing segments at amino or carboxyl terminus in MP-B sequence caused a remarkable decrease in the antibody-binding and immunogenic activities of the peptide. The Lys residues located at amino and carboxyl terminal segments of MP-B, especially Lys4, appear to play a critical role in the binding interaction and the immunogenicity of the peptide.
- Published
- 1995