title: Antimicrobial activity and mechanism of PDC213, an endogenous peptide from human milk.
abstract: 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.
authors.affiliation: 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.
authors.forename: Yazhou
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Nanjing Maternal and Child Health Medical Institute, Nanjing Maternal and Child Health Hospital, Obstetrics and Gynecology Hospital Affiliated to Nanjing Medical University, Nanjing, China.
authors.forename: Yahui
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Nanjing Maternal and Child Health Medical Institute, Nanjing Maternal and Child Health Hospital, Obstetrics and Gynecology Hospital Affiliated to Nanjing Medical University, Nanjing, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Endocrinology, Nanjing Medical University Affiliated Children's Hospital, Nanjing, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Nanjing Maternal and Child Health Medical Institute, Nanjing Maternal and Child Health Hospital, Obstetrics and Gynecology Hospital Affiliated to Nanjing Medical University, Nanjing, China.
authors.forename: Linping
authors.initials: L
authors.lastname: Yan
authors.affiliation: Nanjing Maternal and Child Health Medical Institute, Nanjing Maternal and Child Health Hospital, Obstetrics and Gynecology Hospital Affiliated to Nanjing Medical University, Nanjing, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Chen
authors.affiliation: Nanjing Maternal and Child Health Medical Institute, Nanjing Maternal and Child Health Hospital, Obstetrics and Gynecology Hospital Affiliated to Nanjing Medical University, Nanjing, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Wang
authors.affiliation: Nanjing Maternal and Child Health Medical Institute, Nanjing Maternal and Child Health Hospital, Obstetrics and Gynecology Hospital Affiliated to Nanjing Medical University, Nanjing, China.
authors.forename: Hongjie
authors.initials: H
authors.lastname: Ruan
authors.affiliation: Nanjing Maternal and Child Health Medical Institute, Nanjing Maternal and Child Health Hospital, Obstetrics and Gynecology Hospital Affiliated to Nanjing Medical University, Nanjing, China.
authors.forename: Chenbo
authors.initials: C
authors.lastname: Ji
authors.affiliation: Nanjing Maternal and Child Health Medical Institute, Nanjing Maternal and Child Health Hospital, Obstetrics and Gynecology Hospital Affiliated to Nanjing Medical University, Nanjing, China. Electronic address: xwcui@njmu.edu.cn.
authors.forename: Xianwei
authors.initials: X
authors.lastname: Cui
authors.affiliation: Department of Pediatrics, The Third Affiliated Hospital of Xinxiang Medical University, Xinxiang, China. Electronic address: wangjiaqin2005@sina.com.
authors.forename: Jiaqin
authors.initials: J
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002364:Caseins / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D004247:DNA / Q000378:metabolism; D006801:Humans; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D008895:Milk, Human / Q000737:chemistry*; D010446:Peptide Fragments / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects; D015008:Yersinia enterocolitica / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D002364:Caseins; C000620311:PDC213 peptide, human; D010446:Peptide Fragments; D004247:DNA
keywords: Antimicrobial activity; Endogenous peptides; Human milk; PDC213