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W Boos

Publications and source records attributed to W Boos.

156 records · Page 9Linked to original sources

Regulation of the -methylgalactoside transport system and the galatose-binding protein by the cell cycle of Escherichia coli.

The synthesis of the periplasmic galactose-binding protein of E. coli is regulated by events occurring during its cell cycle, and proceeds in synchronized cells for only a short period after cell division is completed. Transport activity mediated by the beta-methylgalactoside transport system follows closely the synthesis pattern of the binding protein.A mutant, E. coli BUG-6, exhibits temperature-sensitive cell division [Reeve et al. (1970) J. Bacteriol. 104, 1052-1064], synthesizing galactose-binding protein at the permissive but not at the nonpermissive temperature. Galactose-binding protein synthesized at the permissive temperature is not degraded after the culture is shifted to the nonpermissive temperature. Polyacrylamide gel electrophoresis of the periplasmic proteins of BUG-6 grown at the permissive and nonpermissive temperatures suggests that several, but not all, periplasmic proteins are subject to the same regulatory control by the cell cycle as the galactose-binding protein.

Alanine↗

The OmpC protein of Yersinia enterocolitica: purification and properties.

OmpC, one of the major outer membrane proteins of Yersinia enterocolitica, was isolated and purified to homogeneity. When solubilized at room temperature, this protein appeared on SDS polyacrylamide gel electrophoresis as an oligomer. After heating to the temperature of boiling water, the apparent molecular weight of the monomer was 36,000. The incorporation of purified OmpC into black lipid membranes resulted in an increase in membrane conductance demonstrating pore-forming activity. The reconstituted pores exhibited the characteristics of general diffusion pores. They showed cation selectivity and had a single channel conductance of 1.3 nS in 1.0 M KCl. Assuming a constant diameter of the pore, a length of 6 nm (the width of the outer membrane) and the same ion conductivity inside and outside the pore, the diameter of the pore protein was estimated as 1.0 nm. Polyclonal antibodies were raised against the native, pore-forming protein preparation. These antibodies did not recognize the denatured form of the protein, but cross-reacted with native OmpC and OmpF of Escherichia coli. The regulation of OmpC expression in Y. enterocolitica was dependent on the osmolarity of the medium in the same way as in E. coli.

Bacterial Outer Membrane Proteins↗