Lim Shin Saeng, Song Yun Mi, Jang Mi Hyang, Kim Yangmee, Hahm Kyung-Soo, Shin Song Yub
Department of Bio-Materials, Graduate School and Research Center for Proteineous Materials, Chosun University, Kwangju 501-759, Korea.
Protein Pept Lett. 2004 Feb;11(1):35-40. doi: 10.2174/0929866043478383.
Pleurocidin (Ple), a 25-residue alpha-helical antimicrobial peptide, isolated from skin mucosa of the winter flounder, shows potent bacterial cell selectivity. In this study, the effect of two glycine residues in positions 13 and 17 of Ple on structure and bacterial cell selectivity was investigated by Gly-->Ala substitution. Ala-substitution (Gly(13, 17)-->Ala, Gly13-->Ala and Gly17-->Ala) in positions 13 and 17 of Ple did not induce a significant change in antibacterial activity, but increased hemolytic activity. Both Gly(13, 17)-->Ala and Gly17-->Ala substitution did not cause a remarkable change in alpha-helical content in SDS micelles, while Gly(13, 17)-->Ala substitution caused a drastic increase in alpha-helical content. These results suggest that the hinge region from Gly13 to Gly17 of Ple is assumed to provide its conformational flexibility and bacterial cell selectivity.
杀鲆肽（Ple）是一种从冬鲽皮肤黏膜中分离出的由25个氨基酸残基组成的α-螺旋抗菌肽，具有很强的细菌细胞选择性。在本研究中，通过甘氨酸到丙氨酸的替换，研究了Ple第13位和第17位的两个甘氨酸残基对其结构和细菌细胞选择性的影响。Ple第13位和第17位的丙氨酸替换（甘氨酸（13, 17）→丙氨酸、甘氨酸13→丙氨酸和甘氨酸17→丙氨酸）并未引起抗菌活性的显著变化，但溶血活性增加。甘氨酸（13, 17）→丙氨酸和甘氨酸17→丙氨酸替换在SDS胶束中并未引起α-螺旋含量的显著变化，而甘氨酸（13, 17）→丙氨酸替换导致α-螺旋含量急剧增加。这些结果表明，Ple中从甘氨酸13到甘氨酸17的铰链区被认为提供了其构象灵活性和细菌细胞选择性。
