title: Refining the eosinophil cationic protein antibacterial pharmacophore by rational structure minimization.
abstract: Sequence analysis of eosinophil cationic protein (ECP), a ribonuclease of broad antimicrobial activity, allowed identification of residues 1-45 as the antimicrobial domain. We have further dissected ECP(1-45) with a view to defining the minimal requirements for antimicrobial activity. Structure-based downsizing has focused on both α-helices of ECP(1-45) and yielded analogues with substantial potency against Gram-negative and -positive strains. Analogues ECP(8-36) and ECP(6-17)-Ahx-(23-36) (Ahx, 6-aminohexanoic acid) involve 36% and 40% size reduction relative to (1-45), respectively, and display a remarkably ECP-like antimicrobial profile. Both retain segments required for self-aggregation and lipolysaccharide binding, as well as the bacterial agglutination ability of parent ECP. Analogue (6-17)-Ahx-(23-36), in particular, is shown by NMR to preserve the helical traits of the native 8-16 (α1) and 33-36 (α2) regions and can be proposed as the minimal structure capable of reproducing the activity of the entire protein.
authors.affiliation: Department of Biochemistry and Molecular Biology, Universitat Autònoma de Barcelona, E-08193 Cerdanyola del Vallès, Spain.
authors.forename: Marc
authors.initials: M
authors.lastname: Torrent
authors.forename: David
authors.initials: D
authors.lastname: Pulido
authors.forename: Beatriz G
authors.initials: BG
authors.lastname: de la Torre
authors.forename: M Flor
authors.initials: MF
authors.lastname: García-Mayoral
authors.forename: M Victòria
authors.initials: MV
authors.lastname: Nogués
authors.forename: Marta
authors.initials: M
authors.lastname: Bruix
authors.forename: David
authors.initials: D
authors.lastname: Andreu
authors.forename: Ester
authors.initials: E
authors.lastname: Boix
mesh_terms: D000371:Agglutination; D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology; D047150:Eosinophil Cationic Protein / Q000737:chemistry*; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D006461:Hemolysis; D006801:Humans; D008070:Lipopolysaccharides / Q000737:chemistry; D008081:Liposomes; D009682:Magnetic Resonance Spectroscopy; D008823:Micelles; D008826:Microbial Sensitivity Tests; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D017433:Protein Structure, Secondary; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D008070:Lipopolysaccharides; D008081:Liposomes; D008823:Micelles; D010455:Peptides; D047150:Eosinophil Cationic Protein