Showing papers on "Antimicrobial peptides published in 1990"
TL;DR: In this article, it was shown that defensins form voltage-dependent, weakly anion-selective channels in planar lipid bilayer membranes, and this channel-forming ability contributes to their antimicrobial properties observed in vitro.
Abstract: Defensins are cationic, cysteine-rich peptides (Mr = 3500-4000) found in the cytoplasmic granules of neutrophils and macrophages. These peptides possess broad antimicrobial activity in vitro against bacteria, fungi, tumor cells, and enveloped viruses, and they are believed to contribute to the "oxygen-independent" antimicrobial defenses of neutrophils and macrophages. Pathophysiologic studies in vitro have pointed to the plasma membrane as a possible target for the cytotoxic action of defensins. We report here that defensins form voltage-dependent, weakly anion-selective channels in planar lipid bilayer membranes, and we suggest that this channel-forming ability contributes to their antimicrobial properties observed in vitro.
514 citations
TL;DR: It is found that digestion of cathepsin G with clostripain caused a loss of proteolytic activity in this neutrophil proteinase, however, bactericidal activity in in vitro assays against Staphylococcus aureus and Neisseria gonorrhoeae was retained.
116 citations
TL;DR: It is speculated that CRS1C and CRS4C represent a new family of nondefensin antimicrobial peptides in the mouse small bowel.
115 citations
TL;DR: It is concluded that bacteria are sensitive to the cidal mechanism involved indefensin-mediated bacterial killing and that the conditions of this assay system support the killing of bacteria by the defensin peptides.
Abstract: Oral, gram-negative, facultative bacteria, including Actinobacillus actinomycetemcomitans, Eikenella corrodens, and Capnocytophaga spp. have been associated with destructive periodontal infection. Neutrophils play a critical role in defending the periodontium against destructive infection. Defensins are antimicrobial peptides that have been isolated in human, rabbit, guinea pig, and rat leukocytes that may constitute an important nonoxidative mechanism of killing. The purpose of this study was to examine the sensitivity of a battery of oral, gram-negative, facultative bacteria to the bactericidal effects of the isolated rabbit peptide NP-1. All species tested were killed by NP-1; however, there was strain-to-strain variation in sensitivity. The bactericidal effect was not dependent on net bacterial growth, although metabolic activity was evident as assessed by bacterial oxygen consumption. We conclude that bacteria are sensitive to the cidal mechanism involved in defensin-mediated bacterial killing and that the conditions of this assay system support the killing of bacteria by the defensin peptides.
30 citations
Patent•
25 Oct 1990TL;DR: In this paper, a new class of polypeptides with antimicrobial activity, termed tracheal antimicrobial peptides (tracheal ACP), were proposed. But the methods for the production and use of these peptides were not described.
Abstract: The present invention provides a new class of polypeptides with antimicrobial activity, termed "tracheal antimicrobial peptides," cDNA sequences encoding for the peptides and methods for the production and use thereof.
21 citations
TL;DR: The results suggest that magainin‐2 may be modified by PKC through phosphorylation and that certain synthetic analogues of magainins may be used as inhibitors of PKC.
13 citations
01 Mar 1990
TL;DR: Five antimicrobial peptides were extracted from the cytoplasmic granules of rabbit neutrophils with 0.01 mol/L citric acid and were referred to as NP1, NP2, NP3, NP4, and NP5 by virtue of preparative polyacrylamide gel electrophoresis.
Abstract: Five antimicrobial peptides were extracted from the cytoplasmic granules of rabbit neutrophils with 001 mol/L citric acid SDS-PAGE gel densitometric analysis of the citric acid extract showed that they accounted for 34%-42% of the total extract proteins When subjected to acid urea polyacrylamide gel electrophoresis, five peptides migrated much further to the cathode than lysozyme Beginning with the most cathodal component, they were in turn referred to as NP1, NP2, NP3, NP4, and NP5 They were purified from the citric acid extract by virtue of preparative polyacrylamide gel electrophoresis Each of them was of low molecular weight (2,500-6,000) as determined by SDS-PAGE Three of the peptides were tested in vitro for fungicidal activity When Candida albicans (10(7)/ml) were incubated with 125 micrograms/ml of NP1 or NP2 at 37 degrees C for 2 h, the death rates of the organisms were 966% and 933% respectively NP3 was shown to be active against Candida albicans although less potent than NP1 and NP2
1 citations