Optimization of Host Cell-Compatible, Antimicrobial Peptides Effective against Biofilms and Clinical Isolates of Drug-Resistant Bacteria.

Here, we describe the continued synthetic molecular evolution of a lineage of host-compatible antimicrobial peptides (AMP) intended for the treatment of wounds infected with drug-resistant, biofilm-forming bacteria. The peptides tested are variants of an evolved AMP called d-amino acid CONsensus with Glycine Absent (d-CONGA), which has excellent antimicrobial activities and . In this newest generation of rational d-CONGA variants, we tested multiple sequence-structure-function hypotheses that had not been tested in previous generations.

Dps (PA0962) Functions in HO Mediated Oxidative Stress Defense and Exhibits In Vitro DNA Cleaving Activity.

We report the structural, biochemical, and functional characterization of the product of gene PA0962 from PAO1. The protein, termed Pa Dps, adopts the Dps subunit fold and oligomerizes into a nearly spherical 12-mer quaternary structure at pH 6.0 or in the presence of divalent cations at neutral pH and above.

Bacterioferritin Is Assembled from FtnA and BfrB Subunits with the Relative Proportions Dependent on the Environmental Oxygen Availability.

Ferritins are iron storage proteins assembled from 24 subunits into a spherical and hollow structure. The genomes of many bacteria harbor genes encoding two types of ferritin-like proteins, the bacterial ferritins (Ftn) and the bacterioferritins (Bfr), which bind heme. The genome of PAO1 (like the genomes of many bacteria) contains genes coding for two different types of ferritin-like molecules, (PA4235) and (PA3531).

Small Molecule Inhibitors of the Bacterioferritin (BfrB)-Ferredoxin (Bfd) Complex Kill Biofilm-Embedded Cells.

Bacteria depend on a well-regulated iron homeostasis to survive adverse environments. A key component of the iron homeostasis machinery is the compartmentalization of Fe in bacterioferritin and its subsequent mobilization as Fe to satisfy metabolic requirements. In Fe is compartmentalized in bacterioferritin (BfrB), and its mobilization to the cytosol requires binding of a ferredoxin (Bfd) to reduce the stored Fe and release the soluble Fe.

Inhibiting Iron Mobilization from Bacterioferritin in Impairs Biofilm Formation Irrespective of Environmental Iron Availability.

Although iron is essential for bacteria, the nutrient presents problems of toxicity and solubility. Bacteria circumvent these problems with the aid of iron storage proteins where Fe is deposited and, when necessary, mobilized as Fe for metabolic requirements. In , Fe is compartmentalized in bacterioferritin (BfrB), and its mobilization as Fe requires specific binding of a ferredoxin (Bfd) to reduce the stored Fe.

Structural and mutational analyses of the Leptospira interrogans virulence-related heme oxygenase provide insights into its catalytic mechanism.

Heme oxygenase from Leptospira interrogans is an important virulence factor. During catalysis, redox equivalents are provided to this enzyme by the plastidic-type ferredoxin-NADP+ reductase also found in L. interrogans.

Heme-iron utilization by Leptospira interrogans requires a heme oxygenase and a plastidic-type ferredoxin-NADP(+) reductase.

Background: Heme oxygenase catalyzes the conversion of heme to iron, carbon monoxide and biliverdin employing oxygen and reducing equivalents. This enzyme is essential for heme-iron utilization and contributes to virulence in Leptospira interrogans.

Methods: A phylogenetic analysis was performed using heme oxygenases sequences from different organisms including saprophytic and pathogenic Leptospira species.

Redox proteins as targets for drugs development against pathogens.

Antimicrobial drug resistance in pathogens is an increasing human health problem. The rapid loss of effectiveness in antibiotics treatments and the accumulation of multi-resistant microbial strains are increasing worldwide threats. Moreover, several infectious diseases have been neglected for years and new antimicrobial treatments are lacking.

Genetic diversity of Cercospora kikuchii isolates from soybean cultured in Argentina as revealed by molecular markers and cercosporin production.

Leaf blight and purple seed, caused by the fungal pathogen Cercospora kikuchii (Matsumoto & Tomoyasu) M. W. Gardner are very important diseases of soybean (Glycine max L.