Proteomic and metabolic characterization of a Candida albicans mutant resistant to the antimicrobial peptide MUC7 12-mer

MUC7 12-mer is a cationic peptide derived from the N-terminal portion of human mucin MUC7, exhibiting potent antibacterial and antifungal properties. To advance our knowledge regarding the mechanisms of action of MUC7 peptide against an opportunistic fungal pathogen Candida albicans, we sought to develop and characterize mutant(s) resistant to this peptide. One of the selected mutants, designated #37, was much less susceptible to the MUC7 12-mer in a killing assay than the parental strain (ED(50)>40 vs. c. 6 microM, respectively). Difference gel electrophoresis (DIGE) analysis of the mutant revealed elevation of several glycolytic enzymes. The mutant also exhibited lowered ATP contents along with a relatively lower rate of oxygen consumption, as well as inability to grow on nonfermentable carbon sources. These properties are likely to be associated with changes in metabolic regulation, rather than lack of functional mitochondria, as determined by rhodamine 123 staining. Analysis of interaction between fluorescently labeled peptide and cells of both strains revealed that resistance of the mutant #37 is associated with changes in the process of transition between surface-bound state of the peptide to its internalization marking cell death.     

Characteristics of the blood oxygen transport function in angina pectoris patients receiving treatment aimed at correcting the L-arginine-NO pathway

The oxygen transport function of the blood was studied in angina pectoris patients treated with nitrosorbide to correct the L-arginine-NO pathway. A series of parameters (the O₂ content of venous blood, blood oxygen capacity, blood oxygenation level, methemoglobin content, oxygen affinity of methemoglobin, and central hemodynamic parameters) were determined. The oxygen affinity of hemoglobin in patients with functional class I and II stable exertional angina decreased according to the severity of the disease and, therefore, can be considered a criterion of an unfavorable course of the disease. Nitrosorbide therapy resulted in an increase in the oxygen affinity of hemoglobin.     

Crystallization and preliminary X-ray diffraction studies of the lectin from Erythrina corallodendron

The lectin from Erythrina corallodendron, specific for N-acetyllactosamine, crystallizes in the hexagonal space group P6(1) (P6(5)) with unit cell dimensions a = b = 136.3 A, c = 83.2 A and one dimer of Mr 60,000 in the asymmetric unit. The crystals are suitable for high-resolution work.     

ConA-mediated binding and uptake of purified alpha-galactosidase A in Fabry fibroblasts

In most human tissues there are at least two different alpha-galactosidases, A and B. The former is deficient in patients hemizygous for Fabry disease. We have isolated it from human placenta and found that it was labile even at culture conditions, but was stabilized after binding to concanavalin A (conA). The alpha-galactosidase activity was markedly increased in Fabry fibroblasts when these were treated with conA and exposed to alpha-galA at 37 degrees C. The maximum activity was obtained after 1/2-2 h of incubation and was maintained for at least 4 h. The binding and uptake of conA into Fabry cells was followed by microscopical studies of fluorescein-labelled conA. We assume that alpha-galA is taken up by endocytosis of the enzyme-conA complex.     

Function of phenolic substances in the degradation system of indole-3-acetic acid in strawberries

The homogenate of different strawberry organs inhibits the degradation of IAA in the presence of horse radish peroxidase, while intact strawberry tissues are able to degrade IAA. The chemical nature of peroxidase inhibitors present, in strawberry tissues was in vestigated. Using paper chromatography the following polyphenolic substances inhibiting peroxidase activity were identified: chlorogenic, caffeic, ellagic, gentisic, gallic, and vanillic acids, quercetin and pelarginidin. Monophenolic compounds, also present in strawberry, such as p-hydroxy-phenyloacetic acid and p-hydroxybenzoic acid, are strong stimulators of IAA oxidase. Abscisic acid in very high concentration (1×10^?4M) enhances degradation of IAA by peroxidase. When both poly-and monophenolic compounds at equimolar concentrations are present in the system, only the inhibition of IAA degradation occurs. Tissue explants from the strawberry leaves and petiole degrade less IAA if they are previously forced to synthetize more polyphenols under illumination. Although the difference in IAA-decarboxylation activity between the illumination and dark treated explants was relatively small, nevertheless it was consistent and appears to be very important from a physiological point of view suggesting that there exists a regulatory relationin vivo between IAA degradation and the presence of phenolsin plant tissue. Electron microscope data revealed that phenolic substances are specially isolated from cytoplasm of the receptacle cells.