Characterization of RP 333, a gene encoding CapD of Rickettsia prowazekii with UDP-glucose 4-epimerase activity.

The genetic mechanism of membrane assembly in Rickettsia prowazekii, the causative agent of epidemic typhus, is unknown. Recent progress in genomics of this small intracellular bacterium prompted us to explore membrane biogenesis as it pertains to identification and characterization of gene products that are of importance in polysaccharide biosynthesis. We chose to define the function of the R.

Monoamines and their metabolites in the freshwater snail Biomphalaria glabrata.

Metabolism of the major monoamines and their functions were studied in the freshwater snail Biomphalaria glabrata. In both juvenile and adult snails, the plasma (cell-free hemolymph) appears to act as a reservoir for most of these monoamines and their metabolites including among others, L-dopa and dopamine as major constituents. Significant quantities of L-tryptophan, precursor of indoleamines, also was found in the plasma.

Inhibition of Candida albicans growth by calprotectin in the absence of direct contact with the organisms.

Calprotectin is a calcium- and zinc-binding protein that is present in neutrophil cytoplasm and abscess fluid supernatants. This protein appears to inhibit microbial growth through competition for zinc; however, experiments to show that calprotectin can inhibit growth of microorganisms across filter membranes have yielded conflicting results to date. To prevent recontamination of the filtrate by zinc in this type of experiment, Candida albicans was cultured on filter membranes placed on top of an agarose gel containing calprotectin.

Antimicrobial activity of calprotectin isolated from human empyema fluid supernatants.

Abscess and empyema fluid supernatants have zinc-reversible antimicrobial activity that is thought to be due to calprotectin, a calcium- and zinc-binding protein present within neutrophil cytoplasm. The present studies were undertaken to determine if calprotectin isolated from human empyema fluid supernatants demonstrated similar antimicrobial activity to that of the original specimens. The characteristics of the calprotectin complex on SDS-PAGE and Western blotting with specific antisera were similar in neutrophil lysates and in empyema fluid supernatants.

Resistance of zinc-supplemented Candida albicans cells to the growth inhibitory effect of calprotectin.

Calprotectin is a neutrophil cytoplasmic protein with significant microbistatic activity. This protein may compete for zinc, or the metal may inactivate a different microbistatic activity of the protein. To distinguish between these possibilities, the sensitivity to calprotectin was determined for zinc-supplemented Candida albicans cells.

Dominance of metallothionein in metal ion buffering in yeast capable of synthesis of (gamma EC)nG isopeptides.

The relationship of yeast metallothionein (MT) and (gamma EC)nG isopeptides (phytochelatins) in metal ion buffering was assessed. The effect of constitutive expression of yeast metallothionein (MT) genes on accumulation of metal-(gamma EC)nG isopeptide (phytochelatin) complexes was analyzed in Candida glabrata and Schizosaccharomyces pombe cultures incubated in the presence of cadmium salts. Constitutive expression of the Saccharomyces cerevisiae MT (CUP1) gene inhibited the accumulation of metal-phytochelatin complexes in both C.

Distinct metal binding configurations in ACE1.

The ACE1 protein of Saccharomyces cerevisiae mediates the metal-induced expression of the CUP1 metallothionein (MT) genes. Curiously, ACE1 resembles the MT protein in the types of metal complexes that form. ACE1 binds Cd(II) and Cu(I) ions in distinct configurations, but only the Cu(I) conformer of ACE1 forms a high-affinity and specific complex with DNA.

Conversion in the peptides coating cadmium:sulfide crystallites in Candida glabrata.

Cultures of Candida glabrata treated with CdCl2 form intracellular Cd(II) complexes that evolve with the time of culturing. Initially, glutathione (gamma ECG) appears to be the major buffering component. One type of Cd(II)-glutathione complex exists as a cadmium:sulfide (CdS) crystallite coated with glutathione.