tailieunhanh - Báo cáo Y học: Bass hepcidin is a novel antimicrobial peptide induced by bacterial challenge

We report the isolation of a novel antimicrobial peptide, bass hepcidin, from the gill of hybrid striped bass, white bass (Morone chrysops) · striped bass (M. saxatilis). After the intraperitoneal injection of Micrococcus luteus and Escherichia coli, the peptide was purified from HPLC fractions with antimicrobial activity against Escherichia coli. Sequencing by Edman degradation revealed a 21-residue peptide (GCRFCCNCCPNMSGCGVCCRF) with eight putative cysteines. Molecular mass measurements of the native peptide and the reduced and alkylated peptide confirmed the sequence with four intramolecular disulfide bridges | Eur. J. Biochem. 269 2232-2237 2002 FEBS 2002 doi Bass hepcidin is a novel antimicrobial peptide induced by bacterial challenge Hiroko Shike1 Xavier Lauth1 Mark E. Westerman2 Vaughn E. Ostland2 James M. Carlberg2 Jon C. Van Olst2 Chisato Shimizu1 Philippe Bulet3 and Jane C. Burns1 1 Department of Pediatrics University of California San Diego School of Medicine La Jolla CA USA 2 Kent SeaTech Corporation San Diego CA USA 3Institut de Biologie Moleculaire et Cellulaire CNRS Reponse Immunitaire et Developpement chez les Insectes Strasbourg France We report the isolation of a novel antimicrobial peptide bass hepcidin from the gill of hybrid striped bass white bass Morone chrysops X striped bass M. saxatilis . After the intraperitoneal injection of Micrococcus luteus and Escherichia coli the peptide was purified from HPLC fractions with antimicrobial activity against Escherichia coli. Sequencing by Edman degradation revealed a 21-residue peptide GCRFCCNCCPNMSGCGVCCRF with eight putative cysteines. Molecular mass measurements of the native peptide and the reduced and alkylated peptide confirmed the sequence with four intramolecular disulfide bridges. Peptide sequence homology to human hepcidin and other predicted hepcidins indicated that the peptide is a new member of the hepcidin family. Nucleotide sequences for cDNA and genomic DNA were determined for white bass. A predicted prepropeptide 85 amino acids consists of three domains a signal peptide 24 amino acids prodomain 40 amino acids and a mature peptide 21 amino acids . The gene has two introns and three exons. A TATA box and several consensus-binding motifs for transcription factors including C EBP nuclear factor-KB and hepatocyte nuclear factor were found in the region upstream of the transcriptional start site. In white bass liver hepcidin gene expression was induced 4500-fold following challenge with the fish pathogen Streptococcus iniae while expression levels remained low in all