Although protein carbonyl formation is an index of oxidative stress in skeletal muscles, the exact proteins, which undergo oxidation in these muscles, remain unknown. We used 2D electrophoresis, immunoblotting, and mass spectrometry to identify carbonylated proteins in the diaphragm in septic animals. Rats were injected with saline (control) or Escherichia coli lipopolysaccharides (LPS) and killed after various intervals. Diaphragm protein carbonylation increased significantly and peaked 12 h after LPS injection, and it was localized both inside muscle fibers and in blood vessels supplying muscle fibers. Aldolase A, glyceraldehyde 3-phosphate dehydrogenase, enolase 3beta, mitochondrial and cytosolic creatine kinases, alpha-actin, carbonic anyhdrase III, and ubiquinol-cytochrome c reductase were all carbonylated in septic rat diaphragms. In addition, we found significant negative correlations between the intensity of carbonylation and creatine kinase and aldolase activities. We conclude that glycolysis, ATP production, CO2 hydration, and contractile proteins are targeted by oxygen radicals inside the diaphragm during sepsis.

The ability to obtain carbon and energy is a major requirement to exist in any environment. For several ascomycete fungi, (post-)genomic analyses have shown that species that occupy a large variety of habitats possess a diverse enzymatic machinery, while species with a specific habitat have a more focused enzyme repertoire that is well-adapted to the prevailing substrate. White-rot basidiomycete fungi also live in a specific habitat, as they are found exclusively in wood. In this study, we evaluated how well the enzymatic machinery of the white-rot fungus Dichomitus squalens is tailored to degrade its natural wood substrate. The transcriptome and exoproteome of D. squalens were analyzed after cultivation on two natural substrates, aspen and spruce wood, and two non-woody substrates, wheat bran and cotton seed hulls. D. squalens produced ligninolytic enzymes mainly at the early time point of the wood cultures, indicating the need to degrade lignin to get access to wood polysaccharides. Surprisingly, the response of the fungus to the non-woody polysaccharides was nearly as good a match to the substrate composition as observed for the wood polysaccharides. This indicates that D. squalens has preserved its ability to efficiently degrade plant biomass types not present in its natural habitat.