Anti-Caly polyclonal antibody

Bacillus cereus frequently causes food poisoning or nosocomial diseases. Vegetative cells express the novel surface metalloproteinase camelysin (casein-cleaving metalloproteinase) during exponential growth on complex, peptide-rich media. Camelysin is strongly bound to the cell surface and can be solubillized only by detergents or butanol. Camelysin spontaneously migrates from the surface of intact bacterial cells to preformed liposomes. The complete sequence of the camelysin-encoding gene, calY, was determined by reverse PCR on the basis of the N-terminal sequence and some internal tryptic cleavage peptides. The calY gene codes for a polypeptide of 21.569 kDa with a putative signal peptide of 27 amino acids (2.513 kDa) preceding the mature protein (19.056 kDa). Although the predicted amino acid sequence of CalY does not exhibit a typical metalloprotease consensus sequence, high-pressure liquid chromatography-purified camelysin contains one zinc ion per protein molecule. Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry and tryptic peptide mass fingerprinting confirmed the identity of this zinc-binding protein as CalY. Disruption of the calY gene results in a strong decrease in the cell-bound proteolytic activity on various substrates.

The electrical conductivity of the caly fraction of three variable charge soils in 10(-4) N HCl or H2SO4 or 10(-4) M H3PO4 was measured with alternating current of frequencies ranging from 300 Hz to 1.7 MHz. It increased beyond a threshold frequency, reached a plateau region, and then increased again as the frequency was increased. This threshold freqency was of the order phosphate > sulfate > chloride. The relative conductivity, i.e., the conductivity of the suspension minus that of the equilibrium solution at a given frequency to that at 300 Hz, was larger for chloride than that for sulfate and phosphate at the plateau region but was of the reversed order at 1.7 MHz. We suggest that the increased conductivity at the former frequency was caused by anions at a lower bonding energy level and that at 1.7 MHz by anions at a higher bonding energy level. Ferralsol showed distinctly stronger bonding for anions, particularly for phosphate, than Ferric luvisol and Acrisol.