Antimicrobial peptides (AMPs), of which big defensins are examples, are an important component of the natural defenses of most living organisms, and possess remarkable microbicidal activities. In the present study, using expressed-sequence tag sequences from a cDNA library and RACE, the full-length cDNA sequence of the big defensin gene from the triangle-shell pearl mussel, Hyriopsis cumingii, ...

Human neutrophils contain three isoforms of antimicrobial and cytotoxic peptides in the azurophil granules, which belong to a family of mammalian neutrophil peptides named defensins. Here we investigate the role of these peptides in diffuse panbronchiolitis (DPB). Defensins (human neutrophil peptide-1, -2 and -3) were measured by radioimmunoassay in bronchoalveolar lavage fluid (BALF) of 30 pat...

Salmonella enterica serovar Typhimurium uses two-component regulatory systems (TCRSs) to respond to environmental stimuli. Upon infection, the TCRSs PhoP-PhoQ (PhoPQ) and PmrA-PmrB (PmrAB) are activated by environmental signals detected in the lumen of the intestine and within host cells. TCRS-mediated gene expression leads to upregulation of genes involved in lipopolysaccharide (LPS) modificat...

Among the several toxins used by pathogenic bacteria to target eukaryotic host cells, proteins that exert ADP-ribosylation activity represent a large and studied family of dangerous and potentially lethal toxins. These proteins alter cell physiology catalyzing the transfer of the ADP-ribose unit from NAD to cellular proteins involved in key metabolic pathways. In the present study, we tested th...

Human defensins are natural peptide antibiotics. On the basis of the position and bonding of six conserved cysteine residues, they are divided into two families, designated alpha- and beta-defensins. Human alpha-defensins are expressed predominantly in neutrophils (human neutrophil peptides (HNP) 1-4) or intestinal Paneth cells (human defensins (HD) 5 and 6). Although alpha-defensins have been ...