Antimicrobial activity and mechanism of action of a novel cationic ¦Á-helical octadecapeptide derived from heat shock protein 70 of rice

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• 作者：Masayuki Taniguchi ; Atsuo Ikeda ; Shun-ichi Nakamichi ; Yohei Ishiyama ; Eiichi Saitoh ; Tetsuo Kato ; Akihito Ochiai ; Takaaki Tanaka
• 关键词：Antimicrobial peptide ; Cationic ¦Á-helical peptide ; Porphyromonas gingivalis ; Candida albicans ; Membrane-active peptide
• 刊名：Peptides
• 出版年：2013
• 出版时间：October, 2013
• 年：2013
• 卷：48
• 期：Complete
• 页码：147-155
• 全文大小：1297 K

文摘

Hsp70(241-258), an octadecapeptide derived from the heat shock protein 70 (Hsp70) of rice (Oryza sativa L. japonica), is a novel cationic ¦Á-helical antimicrobial peptide (AMP) that contains four lysine, two arginine, and two histidine residues. The antimicrobial activity of Hsp70(241-258) against Porphyromonas gingivalis, a periodontal pathogen, and Candida albicans, an opportunistic fungal pathogen, was quantitatively evaluated using a chemiluminescence method that measures ATP derived from viable cells. The 50 % growth-inhibitory concentrations of Hsp70(241-258) against P. gingivalis and C. albicans cells were 63 ¦ÌM and 70 ¦ÌM, respectively. Hsp70(241-258) had little or no hemolytic activity even at 1 mM, and showed negligible cytotoxicity up to 300 ¦ÌM. The degrees of calcein leakage from large unilamellar vesicles, which mimic the membranes of Gram-negative bacteria, and 3,3¡ä-dipropylthiadicarbocyanine iodide release from P. gingivalis cells induced by the addition of Hsp70(241-258) increased in a concentration-dependent manner. When Hsp70(241-258) was added to calcein-acetoxymethyl ester-loaded C. albicans cells, calcein release from the cells increased in a concentration-dependent manner. Flow cytometric analysis also showed that the percentages of C. albicans cells stained with propidium iodide, a DNA-intercalating dye, increased as the concentration of Hsp70(241-258) added was increased. Therefore, Hsp70(241-258) appears to exhibit antimicrobial activity against P. gingivalis and C. albicans through membrane disruption. These results suggest that Hsp70(241-258) could be useful as a safe and potent AMP against P. gingivalis and C. albicans in many fields of health care, especially in the control of oral infections.