title: Chemical synthesis, molecular modeling, and antimicrobial activity of a novel bacteriocin, MMFII.
abstract: A new antimicrobial peptide, referred to as MMFII, was purified to homogeneity from lactic acid bacteria Lactococcus lactis, which were isolated from Tunisian dairy product. The complete amino acid sequence of the peptide has been established by amino acid analysis, Edman sequencing, and mass spectrometry and verified by solid-phase chemical synthesis. MMFII is a single-chain 37-residue polypeptide containing a single intramolecular disulfide bond, i.e., TSYGNGVHCNKSKCWIDVSELETYKAGTVSNPKDILW. It shares ca. 35% sequence identity with Leucocin A, a class IIa bacteriocin. Modeling based on the 3-D of Leucocin A shows three beta strands located in the N-terminal region (Thr1-Tyr3, Val7-Asn10, Lys13-Ile16) and an alpha helical domain from Asp17 to Asn31. When plotted as an alpha-helical wheel, the central alpha-helix of MMFII does not exhibit an amphipathic helical structure. The synthetic MMFII (sMMFII), obtained by the solid-phase method, was shown to be indistinguishable from the natural peptide. sMMFII is active against Lactococcus cremoris and Listeria ivanovii bacteria, whereas no activity was detected for any of the synthetic N-terminal truncated MMFII analogs Cys9-Trp37, Trp15-Trp37, and Val18-Trp37.
authors.affiliation: Laboratoire de Biochimie et Biologie Moléculaire, Faculté des Sciencs de Tunis, Département de Biologie, El Manar, 2092 Tunis, Tunisia.
authors.forename: M
authors.initials: M
authors.lastname: Ferchichi
authors.forename: M
authors.initials: M
authors.lastname: Fathallah
authors.forename: P
authors.initials: P
authors.lastname: Mansuelle
authors.forename: H
authors.initials: H
authors.lastname: Rochat
authors.forename: J M
authors.initials: JM
authors.lastname: Sabatier
authors.forename: M
authors.initials: M
authors.lastname: Manai
authors.forename: K
authors.initials: K
authors.lastname: Mabrouk
mesh_terms: D000595:Amino Acid Sequence; D001430:Bacteriocins / Q000138:chemical synthesis* / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology; D005516:Food Microbiology; D017045:Lactococcus / Q000187:drug effects; D013294:Lactococcus lactis / Q000737:chemistry / Q000235:genetics; D008087:Listeria / Q000187:drug effects; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology; D011487:Protein Conformation
chemical_list: D001430:Bacteriocins; D010455:Peptides; C441967:bacteriocin MMFII