Sun Yazhou, Zhou Yahui, Liu Xiao, Zhang Fan, Yan Linping, Chen Ling, Wang Xing, Ruan Hongjie, Ji Chenbo, Cui Xianwei, Wang Jiaqin
Department of Pediatrics, The Third Affiliated Hospital of Xinxiang Medical University, Xinxiang, China; Nanjing Maternal and Child Health Medical Institute, Nanjing Maternal and Child Health Hospital, Obstetrics and Gynecology Hospital Affiliated to Nanjing Medical University, Nanjing, China.
Nanjing Maternal and Child Health Medical Institute, Nanjing Maternal and Child Health Hospital, Obstetrics and Gynecology Hospital Affiliated to Nanjing Medical University, Nanjing, China.
Biochem Biophys Res Commun. 2017 Feb 26;484(1):132-137. doi: 10.1016/j.bbrc.2017.01.059. Epub 2017 Jan 16.
Human milk has always been considered an ideal source of elemental nutrients to both preterm and full term infants in order to optimally develop the infant's tissues and organs. Recently, hundreds of endogenous milk peptides were identified in human milk. These peptides exhibited angiotensin-converting enzyme inhibition, immunomodulation, or antimicrobial activity. Here, we report the antimicrobial activity and mechanism of a novel type of human antimicrobial peptide (AMP), termed PDC213 (peptide derived from β-Casein 213-226 aa). PDC213 is an endogenous peptide and is present at higher levels in preterm milk than in full term milk. The inhibitory concentration curve and disk diffusion tests showed that PDC213 had obvious antimicrobial against S. aureus and Y. enterocolitica, the common nosocomial pathogens in neonatal intensive care units (NICUs). Fluorescent dye methods, electron microscopy experiments and DNA-binding activity assays further indicated that PDC213 can permeabilize bacterial membranes and cell walls rather than bind intracellular DNA to kill bacteria. Together, our results suggest that PDC213 is a novel type of AMP that warrants further investigation.
母乳一直被认为是早产和足月婴儿获取基本营养的理想来源，有助于婴儿组织和器官的最佳发育。最近，在母乳中发现了数百种内源性乳肽。这些肽具有血管紧张素转换酶抑制、免疫调节或抗菌活性。在此，我们报告一种新型人类抗菌肽（AMP），称为PDC213（源自β-酪蛋白213-226氨基酸的肽）的抗菌活性及其作用机制。PDC213是一种内源性肽，在早产母乳中的含量高于足月母乳。抑菌浓度曲线和纸片扩散试验表明，PDC213对新生儿重症监护病房（NICU）常见的医院病原体金黄色葡萄球菌和小肠结肠炎耶尔森菌具有明显的抗菌作用。荧光染料法、电子显微镜实验和DNA结合活性测定进一步表明，PDC213可使细菌细胞膜和细胞壁通透性增加，而不是通过结合细胞内DNA来杀死细菌。总之，我们的结果表明，PDC213是一种新型的抗菌肽，值得进一步研究。
