title: Rational design of mirror-like peptides with alanine regulation.
abstract: To generate effective antimicrobial peptides (AMPs) with good antimicrobial activities and cell selectivity, many synthetic strategies have been implemented to facilitate the development of AMPs. However, these synthetic strategies represent only a small proportion of the methods used for the development of AMPs and are not optimal with the requirements needed for the design of AMPs. In this investigation, we designed a mirror-like structure with a lower charge and a higher number of hydrophobic amino acids. The amino acid sequence of the designed mirror-like peptides was XXYXXXYXXXYXX [X represents L (Leu) and/or A (Ala); Y represents K (Lys)]. These mirror-like peptides displayed antimicrobial activity against both Gram-positive and Gram-negative bacteria. Hemolysis activity and cytotoxicity, detected by using human red blood cells (hRBCs) and human embryonic kidney cells (HEK293), respectively, demonstrated that the frequency of Ala residues in this structure had a regulatory effect on the high hydrophobic region. In particular, KL4A6 showed a greater antimicrobial potency than the other three mirror-like peptides, folded into an α-helical structure, and displayed the highest therapeutic index, suggesting its good cell selectivity. Observations from fluorescence spectroscopy, flow cytometry, and electron microscopy experiments indicated that KL4A6 exhibited good membrane penetration potential by inducing membrane blebbing, disruption and lysis. Therefore, generating mirror-like peptides is a promising strategy for designing effective AMPs with regions of high hydrophobicity.
authors.affiliation: Institute of Animal Nutrition, Northeast Agricultural University, No. 59 Mucai Street, Xiangfang District, Harbin, 150030, People's Republic of China.|Weifang University, Weifang, 261061, People's Republic of China.
authors.forename: Weizhong
authors.initials: W
authors.lastname: Li
authors.affiliation: Institute of Animal Nutrition, Northeast Agricultural University, No. 59 Mucai Street, Xiangfang District, Harbin, 150030, People's Republic of China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Tan
authors.affiliation: Institute of Animal Nutrition, Northeast Agricultural University, No. 59 Mucai Street, Xiangfang District, Harbin, 150030, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.affiliation: Institute of Animal Nutrition, Northeast Agricultural University, No. 59 Mucai Street, Xiangfang District, Harbin, 150030, People's Republic of China.
authors.forename: Lin
authors.initials: L
authors.lastname: Xu
authors.affiliation: Institute of Animal Nutrition, Northeast Agricultural University, No. 59 Mucai Street, Xiangfang District, Harbin, 150030, People's Republic of China.
authors.forename: Na
authors.initials: N
authors.lastname: Dong
authors.affiliation: Institute of Animal Nutrition, Northeast Agricultural University, No. 59 Mucai Street, Xiangfang District, Harbin, 150030, People's Republic of China. mdy296@sohu.com.
authors.forename: Deying
authors.initials: D
authors.lastname: Ma
authors.affiliation: Institute of Animal Nutrition, Northeast Agricultural University, No. 59 Mucai Street, Xiangfang District, Harbin, 150030, People's Republic of China. asshan@neau.edu.cn.
authors.forename: Anshan
authors.initials: A
authors.lastname: Shan
mesh_terms: D000409:Alanine / Q000378:metabolism*; D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000009:adverse effects / Q000138:chemical synthesis* / Q000378:metabolism; D023181:Antimicrobial Cationic Peptides / Q000009:adverse effects / Q000138:chemical synthesis* / Q000378:metabolism; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002463:Cell Membrane Permeability; D002942:Circular Dichroism; D015195:Drug Design; D004912:Erythrocytes / Q000187:drug effects; D006090:Gram-Negative Bacteria / Q000187:drug effects*; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D057809:HEK293 Cells; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008826:Microbial Sensitivity Tests; D017433:Protein Structure, Secondary
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D000409:Alanine
keywords: Alanine regulation; Bactericidal mechanism; Cell selectivity; Mirror-like peptides; Rational design