关键词: 蜂毒肽;反序;抑菌活性;溶血活性, 蜂毒肽, 反序, 抑菌活性, 溶血活性

Abstract:

Melittin is an amphipathic α-helical peptide with 26 amino acids. It has   high antimicrobial activity and  toxicity to  eukaryotic cells. C-terminal 15-residue fragment of melittin(GLPALISWIKRKRQQ-NH2), M(12-26), retained some of the antimicrobial activity but lost most of the hemolytic activitiy. A series of reverse-sequence analogs of M(12-26) with various numbers of basic amino acid residues and various lengths of the hydrophobic segment  were synthesized. In the reverse-sequence analogs, the positive charges introduced by the basic residues and the N-terminal amino group were gathered in the N-terminus, while the hydrophobic segment was located in the C-terminus. The results indicate both of the positive charge and the hydrophobicity of the reverse-sequence analogs were necessary for the antimicrobial and hemolytic activities. At least three N-terminal basic animo acids and eight amino acid residues for the hydrophobic segment were required for high antimicrobial activity. A 11-residue peptide, RetroMel(13-23) was the shortest peptide  retaining the antimicrobial activity. All these of the reverse-sequence analogs possessed very low hemolysis.

Key words: Melittin; Reverse sequence; Antibacterial activity; Hemolytic aetivity, Melittin, Reverse sequence, Antibacterial activity, Hemolytic aetivity