Most swimming bacteria produce thrust by rotating helical filaments called flagella. Typically, the flagella stick out into the external fluid environment; however, in the spirochetes, a unique group that includes some highly pathogenic species of bacteria, the flagella are internalized, being incased in the periplasmic space; i.e., between the outer membrane and the cell wall. This coupling be...

Bacterial expression systems provide economic and logistic advantages in manufacturing proteins for human therapeutic purposes. However, most such proteins accumulate in insoluble biologicaIIy inactive form when overexpressed in bacterial cells. This is the case while attempting to produce recombinant human granulocyte-macrophage colony stimulating factor (hGM-CSF) in E. coli. In this repor...

The Escherichia coli TolC protein is central to toxin export and drug efflux across the inner and outer cell membranes and the intervening periplasmic space. The crystal structure has revealed that TolC assembles into a remarkable α-helical trans-periplasmic cylinder (tunnel) embedded in the outer membrane by a contiguous β-barrel (channel), so providing a large duct open to the outside environ...

The locations of cytochrome cd1 nitrite reductases in Pseudomonas aeruginosa and Pseudomonas fluorescens and copper nitrite reductases in Achromobacter cycloclastes and Achromobacter xylosoxidans were identified. Immunogold labeling with colloidal-gold probes showed that the nitrite reductases were synthesized exclusively in anaerobically grown (denitrifying) cells. Little immunogold label occu...

In Escherichia coli cells carrying wild-type ovalbumin cDNA, some of the recombinant protein was secreted into the periplasmic space. In contrast, a signal-region mutant form of ovalbumin (deletion, Gly1 to Ala39) was not detected in the periplasm despite being synthesized at the same level as the wild-type protein. Chemical and spectroscopic analyses showed that periplasmic ovalbumin assumes a...

A self-regulated high-copy number plasmid containing chloramphenicol resistant gene, for the production of recombinant proteins under the regulation of bacteriophage λpL promoter, was constructed. The designed 5024 base pair expression plasmid contained a heat sensitive repressor cI857 coding gene to regulate the function of λpL promoter under heat shock induction. Using the constructed vector,...

Histochemical techniques applied at the ultrastructural level have clearly established the periplasmic space as the site of alkaline phosphatase activity in Plectonema boryanum. Considerable enzyme activity is found after the organism is placed in a phosphate-free medium for 5 days. This activity is found only in the cellular fraction of the culture with no activity present in the culture mediu...

Under conditions that permitted continued protein synthesis, spheroplasts of Escherichia coli were unable to form active alkaline phosphatase, although they synthesized protein that was antigenically related to alkaline phosphatase subunits. This cross-reacting protein was primarily detected in the medium of the spheroplast culture, and it had properties that closely resembled those of the alka...

The bdellovibrios are extremely small bacteria with the unique property of being parasites of other (gram-negative) bacteria. In the presence of viable and susceptible bacteria a Bdellovibrio cell physically 'attacks' an individual host cell, attaches to its surface, penetrates the cell wall, and multiples within the periplasmic (intramural) space of its prey. The invading Bdellovibrio and its ...

During the conversion of yeast cells to protoplasts, about half of the yeast chitinase was liberated into the medium, an indication that this portion of the enzyme is located in the periplasmic space. At least part of the remaining chitinase appears to be enclosed in vacuoles or in vesicle that co-purify with them, as indicated by a 14-fold enrichment of the enzymatic activity in a vacuole frac...