A short α-helical antimicrobial peptide with antibacterial selectivity

Shin, Song Yub
Hahm, Kyung-Soo

Department of Bio-Materials, Graduate School and Research Center for Proteineous Materials, Chosun University, Gwangju 501-759, Korea

^*Author for correspondence (Fax: +82-62-227-8345 E-mail: [email protected])

Biotechnology Letters 26(9):p 735-739, May 2004.

A 13-residue α-helical peptide (K₆L₅WP), designed from Leu⁶ →Pro substitution of a hemolytic α-helical peptide (K₆L₆W), exhibited strong antibacterial activity (MIC: 2∼4 μm against three Gram-positives and three Gram-negatives) comparable to that of melittin but had no hemolytic activity. Tryptophan fluorescence studies indicated bacterial selectivity of K₆L₅WP is closely related to the selective interaction with negatively charged phospholipids on the surface of bacterial cells. These results suggested that the central Pro⁶ in K₆L₅WP plays an important role in its bacterial cell selectivity. In conclusion, K₆L₅WP with antibacterial selectivity may serve as an attractive candidate for the development of antimicrobial agents.