title: Antimicrobial activity and mechanism of the human milk-sourced peptide Casein201.
abstract: Casein201 is one of the human milk sourced peptides that differed significantly in preterm and full-term mothers. This study is designed to demonstrate the biological characteristics, antibacterial activity and mechanisms of Casein201 against common pathogens in neonatal infection.
  
  
  
  The analysis of biological characteristics was done by bioinformatics. Disk diffusion method and flow cytometry were used to detect the antimicrobial activity of Casein201. Killing kinetics of Casein201 was measured using microplate reader. The antimicrobial mechanism of Casein201 was studied by electron microscopy and electrophoresis.
  
  
  
  Bioinformatics analysis indicates that Casein201 derived from β-casein and showed significant sequence overlap. Antibacterial assays showed Casein201 inhibited the growth of S taphylococcus aureus and Y ersinia enterocolitica. Ultrastructural analyses revealed that the antibacterial activity of Casein201 is through cytoplasmic structures disintegration and bacterial cell envelope alterations but not combination with DNA.
  
  
  
  We conclude the antimicrobial activity and mechanism of Casein201. Our data demonstrate that Casein201 has potential therapeutic value for the prevention and treatment of pathogens in neonatal infection.
authors.affiliation: Nanjing Maternal and Child Health Medical Institute, Nanjing Maternal and Child Health Hospital, Obestetrics and Gynecology Hospital Affiliated to Nanjing Medical University, Nanjing, China; Department of Endocrinology, Children's Hospital of Nanjing Medical University, 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, Obestetrics and Gynecology Hospital Affiliated to Nanjing Medical University, Nanjing, China.
authors.forename: Xianwei
authors.initials: X
authors.lastname: Cui
authors.affiliation: Nanjing Maternal and Child Health Medical Institute, Nanjing Maternal and Child Health Hospital, Obestetrics and Gynecology Hospital Affiliated to Nanjing Medical University, Nanjing, China.
authors.forename: Yanrong
authors.initials: Y
authors.lastname: Fu
authors.affiliation: Nanjing Maternal and Child Health Medical Institute, Nanjing Maternal and Child Health Hospital, Obestetrics and Gynecology Hospital Affiliated to Nanjing Medical University, Nanjing, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Nanjing Maternal and Child Health Medical Institute, Nanjing Maternal and Child Health Hospital, Obestetrics 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, Obestetrics 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, Obestetrics 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, Obestetrics and Gynecology Hospital Affiliated to Nanjing Medical University, Nanjing, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Endocrinology, Children's Hospital of Nanjing Medical University, Nanjing, China. Electronic address: 18951769617@163.com.
authors.forename: Qianqi
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Nanjing Maternal and Child Health Medical Institute, Nanjing Maternal and Child Health Hospital, Obestetrics and Gynecology Hospital Affiliated to Nanjing Medical University, Nanjing, China. Electronic address: shirly_chen221@163.com.
authors.forename: Ting
authors.initials: T
authors.lastname: Chen
mesh_terms: D000595:Amino Acid Sequence; D000890:Anti-Infective Agents / Q000494:pharmacology*; D001424:Bacterial Infections / Q000188:drug therapy / Q000382:microbiology / Q000517:prevention & control; D002364:Caseins / Q000737:chemistry*; D004926:Escherichia coli / Q000187:drug effects / Q000502:physiology; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000502:physiology; D008089:Listeria monocytogenes / Q000187:drug effects / Q000502:physiology; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D008895:Milk, Human / Q000737:chemistry*; D010455:Peptides / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D015008:Yersinia enterocolitica / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure
chemical_list: D000890:Anti-Infective Agents; D002364:Caseins; D010455:Peptides
keywords: Antimicrobial peptides (AMPs); Casein201; S taphylococcusaureus; Y ersinia enterocolitica