title: Antimicrobial peptide, hdMolluscidin, purified from the gill of the abalone, Haliotis discus.
abstract: A 4.7 kDa antimicrobial peptide was purified from the acidified gill extract of the Abalone, Haliotis discus, by cation-exchange and C18 reversed-phase high performance liquid chromatography (HPLC). Comparison of the amino acid sequences and molecular weight of this peptide with those of other known antimicrobial peptides revealed that this antimicrobial peptide have high sequence homology with that of cgMolluscidin and was designated hdMolluscidin. hdMolluscidin is composed of 46 amino acid residues containing several dibasic residue repeats like KK or K-R. hdMolluscidin showed potent antimicrobial activity against both Gram-positive bacteria including Bacillus subtilis and Staphylococcus aureus (minimal effective concentrations [MECs]; 0.8-19.0 μg/mL) and Gram-negative bacteria including Aeromonas hydrophila, Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica, Shigella flexneri, and Vibrio parahemolyticus ([MECs]; 1.0-4.0 μg/mL) without hemolytic activity. However, hdMolluscidin did not show any significant activity against Candida albicans. The secondary structural prediction suggested that hdMolluscidin might not form an ordered or an amphipathic structure. hdMolluscidin did not show membrane permeabilization or leakage ability. The full-length hdMolluscidin cDNA contained 566-bp, including a 5'-untranslated region (UTR) of 63-bp, a 3'-UTR of 359-bp, and an open reading frame of 144-bp encoding 47 amino acids (containing Met). cDNA study of hdMolluscidin suggests that it is expressed as a mature peptide. Our results indicate that hdMolluscidin could relate to the innate immune defenses in abalone and it may not act directly on bacterial membrane.
authors.affiliation: Department of Food Science and Biotechnology, Kunsan National University, Kunsan 54150, South Korea. Electronic address: jungkileun@kunsan.ac.kr.
authors.forename: Jung-Kil
authors.initials: JK
authors.lastname: Seo
authors.affiliation: Department of Biotechnology, Pukyong National University, Busan 48513, South Korea.
authors.forename: Hye-Jin
authors.initials: HJ
authors.lastname: Go
authors.affiliation: Department of Biotechnology, Pukyong National University, Busan 48513, South Korea.
authors.forename: Chan-Hee
authors.initials: CH
authors.lastname: Kim
authors.affiliation: Biotechnology Research Division, Aquaculture Industry Department, National Fisheries Research and Development Institute, Busan 46083, South Korea.
authors.forename: Bo-Hye
authors.initials: BH
authors.lastname: Nam
authors.affiliation: Department of Biotechnology, Pukyong National University, Busan 48513, South Korea. Electronic address: ngpark@pknu.ac.kr.
authors.forename: Nam Gyu
authors.initials: NG
authors.lastname: Park
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002176:Candida albicans / Q000502:physiology; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D049851:Gastropoda / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D005880:Gills / Q000737:chemistry / Q000276:immunology / Q000382:microbiology; D006090:Gram-Negative Bacteria / Q000502:physiology; D006094:Gram-Positive Bacteria / Q000502:physiology; D017433:Protein Structure, Secondary; D016415:Sequence Alignment
chemical_list: D023181:Antimicrobial Cationic Peptides; D018076:DNA, Complementary
keywords: Abalone; Antimicrobial activity; Haliotis discus; Innate immunity; hdMolluscidin