title: Enhancement of the direct antimicrobial activity of Lysep3 against Escherichia coli by inserting cationic peptides into its C terminus.
abstract: Phage lysins are considered promising antimicrobials against resistant bacterial infections. Some lysins have been reported for the prevention and treatment of Gram-positive bacterial infection. Gram-negative bacterial phage lysins, however, can only destroy the bacterial cell wall from inside because of the obstruction of the bacterial outer membrane that prevents direct hydrolysis of the bacterial wall peptidoglycan from the outside, severely restricting the development of lysins against Gram-negative bacteria. In this study, genetic engineering techniques were used to fuse a 5 cationic amino acid polypeptide (KRKRK), a 10 cationic amino acid polypeptide (KRKRKRKRKR), a 15 cationic amino acid polypeptide (KRKRKRKRKRKRKRK), and a polypeptide including both cationic and hydrophobic amino acids (KRKRKFFVAIIP) to the C-terminus of the Escherichia coli phage lysin Lysep3 to obtain four fusion lysins (5aa, 10aa, 15aa, Mix). The bactericidal effects of those four lysins on E. coli were then compared in vitro. Our results showed that the fusion of hydrophobic and positively charged amino acids, Mix, can kill E. coli effectively; the fusion of positively charged amino acids alone at the C-terminus (5aa, 10aa, 15aa) also showed bactericidal activity against E. coli from the outside, with the bactericidal activity gradually increasing with the positive charge at the C-terminus of the lysin. Collectively, improving the positive charge at the C-terminus of E. coli bacteriophage lysin Lysep3 increases its bactericidal ability from outside E. coli, providing a new practical method for the development of anti-Gram-negative bacterial lysins.
authors.affiliation: College of Veterinary Medicine, Jilin University, Xi'an Road 5333, Changchun, People's Republic of China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Ma
authors.affiliation: College of Veterinary Medicine, Jilin University, Xi'an Road 5333, Changchun, People's Republic of China.|Norman Bethune Health Science Center of Jilin University, Xinmin Road 828, Changchun, People's Republic of China.
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Guo
authors.affiliation: College of Veterinary Medicine, Jilin University, Xi'an Road 5333, Changchun, People's Republic of China.
authors.forename: Chencheng
authors.initials: C
authors.lastname: Gao
authors.affiliation: College of Veterinary Medicine, Jilin University, Xi'an Road 5333, Changchun, People's Republic of China.
authors.forename: Rining
authors.initials: R
authors.lastname: Zhu
authors.affiliation: College of Veterinary Medicine, Jilin University, Xi'an Road 5333, Changchun, People's Republic of China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Wang
authors.affiliation: College of Veterinary Medicine, Jilin University, Xi'an Road 5333, Changchun, People's Republic of China.
authors.forename: Ling
authors.initials: L
authors.lastname: Yu
authors.affiliation: College of Veterinary Medicine, Jilin University, Xi'an Road 5333, Changchun, People's Republic of China.
authors.forename: Wanhai
authors.initials: W
authors.lastname: Qin
authors.affiliation: College of Veterinary Medicine, Jilin University, Xi'an Road 5333, Changchun, People's Republic of China.
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Xia
authors.affiliation: College of Veterinary Medicine, Jilin University, Xi'an Road 5333, Changchun, People's Republic of China.
authors.forename: Jingmin
authors.initials: J
authors.lastname: Gu
authors.affiliation: College of Veterinary Medicine, Jilin University, Xi'an Road 5333, Changchun, People's Republic of China. yanguangmou@sohu.com.
authors.forename: Guangmou
authors.initials: G
authors.lastname: Yan
authors.affiliation: College of Veterinary Medicine, Jilin University, Xi'an Road 5333, Changchun, People's Republic of China. leiliancheng@163.com.
authors.forename: Liancheng
authors.initials: L
authors.lastname: Lei
mesh_terms: D000595:Amino Acid Sequence; D023181:Antimicrobial Cationic Peptides / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology*; D001433:Bacteriolysis; D002473:Cell Wall / Q000378:metabolism; D003090:Coliphages / Q000235:genetics* / Q000378:metabolism; D004279:DNA, Viral; D004357:Drug Synergism; D004926:Escherichia coli / Q000187:drug effects* / Q000821:virology; D005818:Genetic Engineering / Q000379:methods; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy / Q000821:virology; D010457:Peptidoglycan / Q000378:metabolism; D014764:Viral Proteins / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D023181:Antimicrobial Cationic Peptides; D004279:DNA, Viral; D010457:Peptidoglycan; D014764:Viral Proteins
keywords: Antimicrobial resistance; Bacteriophage; Bacteriophage lysins; Escherichia coli; Gram-negative bacteria; Superbugs