Characterization of translucent segments observed in an smbA mutant of Escherichia coli

Abstract The smbA gene of Escherichia coli is essential for cell proliferation. The smbA2 mutant shows cold-sensitive colony formation at 22°C. A novel morphological phenotype, formation of a translucent segment at midcell or at a cell pole, was observed by phase-contrastt microscopy at a high frequency in the smbA2 mutant cells incubated in L medium lacking NaCl at 22°C, but not observed in L medium containing 1% NaCl or 20% sucrose at the same temperature. No translucent segment was observed in the wild-type cells in any of the media used. Electron microscopic observation revealed that the translucent segments resulted from the enlargement of a periplasmic space by separation of the inner membrane from the peptidoglycan layer and the outer membrane.     

Structural studies on the murine granulocyte colony-stimulating factor

Granulocyte-colony stimulating factor (G-CSF) is a glycoprotein hemopoietic growth factor which regulates the production of granulocytes and macrophages. Reversed-phase microbore high-performance liquid chromatography was employed to purify a number of tryptic and Staphylococcus aureus V8 proteinase peptides generated from approximately 400 pmol G-CSF purified from medium conditioned by lungs from mice previously injected with endotoxin. N-Terminal amino-acid sequence analyses were performed on the parent polypeptide and on four tryptic peptides and one Staphylococcus aureus V8 protease peptide, yielding 68 unique amino-acid assignments; this corresponds to approximately 38% of the molecule.