title: Killing of Staphylococcus aureus and Salmonella enteritidis and neutralization of lipopolysaccharide by 17-residue bovine lactoferricins: improved activity of Trp/Ala-containing molecules.
abstract: Bovine lactoferricin (LfcinB) has potent antibacterial, antifungal and antiparasitic activities but is also hemolytic. Our objective was to identify LfcinB17-31 derivatives with reduced hemolysis and improved antimicrobial activity via substituting Cys3, Arg4, Gln7, Met10, and Gly14 with more hydrophobic residues. Two peptides, Lfcin4 and Lfcin5, showed higher activity against Staphylococcus aureus and Salmonella enteritidis and lower hemolytic activity than the parent peptide LfcinB17-31. These peptides permeabilized the outer and inner membranes of S. enteritidis; however, Lfcin5 did not permeabilize the inner membrane of S. aureus. Gel retardation and circular dichroism spectra showed that Lfcin4 and Lfcin5 bound to bacterial genomic DNA. Lfcin4 inhibited DNA, RNA and protein synthesis. Both peptides induced the peeling of membranes and the lysis of S. enteritidis. At doses of 10 and 15 mg/kg, Lfcin4 and Lfcin5 reduced the bacterial counts in infected thigh muscles by 0.03‒0.10 and 0.05‒0.63 log10CFU/g of tissue, respectively, within 10 h. Lfcin4 and Lfcin5 enhanced the survival rate of endotoxemic mice; reduced serum IL-6, IL-1β and TNF-α levels; and protected mice from lipopolysaccharide-induced lung injury. These data suggest that Lfcin4 and Lfcin5 may be antimicrobial and anti-endotoxin peptides that could serve as the basis for the development of dual-function agents.
authors.affiliation: Key Laboratory of Feed Biotechnology, Ministry of Agriculture, Beijing 100081, China.|Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Ya
authors.initials: Y
authors.lastname: Hao
authors.affiliation: Key Laboratory of Feed Biotechnology, Ministry of Agriculture, Beijing 100081, China.|Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Na
authors.initials: N
authors.lastname: Yang
authors.affiliation: Key Laboratory of Feed Biotechnology, Ministry of Agriculture, Beijing 100081, China.|Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Xiumin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Key Laboratory of Feed Biotechnology, Ministry of Agriculture, Beijing 100081, China.|Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Da
authors.initials: D
authors.lastname: Teng
authors.affiliation: Key Laboratory of Feed Biotechnology, Ministry of Agriculture, Beijing 100081, China.|Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Ruoyu
authors.initials: R
authors.lastname: Mao
authors.affiliation: Key Laboratory of Feed Biotechnology, Ministry of Agriculture, Beijing 100081, China.|Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Wang
authors.affiliation: Key Laboratory of Feed Biotechnology, Ministry of Agriculture, Beijing 100081, China.|Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Zhanzhan
authors.initials: Z
authors.lastname: Li
authors.affiliation: Key Laboratory of Feed Biotechnology, Ministry of Agriculture, Beijing 100081, China.|Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Wang
mesh_terms: D000409:Alanine / Q000737:chemistry / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D002417:Cattle; D019446:Endotoxemia / Q000139:chemically induced / Q000517:prevention & control; D005260:Female; D007781:Lactoferrin / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors* / Q000633:toxicity; D008297:Male; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008826:Microbial Sensitivity Tests; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology*; D012477:Salmonella enteritidis / Q000187:drug effects* / Q000502:physiology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000502:physiology; D014364:Tryptophan / Q000737:chemistry / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D008070:Lipopolysaccharides; D010446:Peptide Fragments; C557490:lactoferricin (17-30); D014364:Tryptophan; D007781:Lactoferrin; D000409:Alanine