The ability of Helicobacter pylori to survive in the varying acidity of the stomach is considered to be linked to its ability to maintain a tolerable pH in its periplasmic space by acid dependent activation of internal urease activity. Whereas survival of H pylori can occur between a periplasmic pH of 4.0 to 8.0, growth can only occur between a periplasmic pH of 6.0 to 8.0. When urease activity...

O-glycosylation has been considered a limiting factor in protein secretion in filamentous fungi. Overexpression of the yeast DPM1 gene encoding dolichylphosphate mannose synthase (DPMS) in an Aspergillus nidulans mutant (BWB26A) deficient in O-glycosylation caused an increase in the number of secretory vesicles and changes in protein secretion. However, the secretory proteins, primarily O-manno...

The expected discounted penalty with downside jumps has been extensively studied in Gerber and Shiu(1998), Gerber and Landry(1998), Tsai and Wilmott(2002) and others. In this paper, we study the expected discounted penalty in a perturbed compound Poisson model with two sided jumps. We show that it is always twice continuously differentiable provided that the jump size distribution has a bounded...

FtsH is a membrane-bound and ATP-dependent protease of Escherichia coli, known to degrade SecY, a membrane protein for protein translocation, and CII, a soluble transcription factor for lysis/lysogeny decision of phage lambda. FtsH forms a homo-oligomeric complex as well as a hetero-oligomeric complex with HflKC, a putative modulator of FtsH. Although FtsH has a small periplasmic region, HflKC ...

Six independent secretion-defective mutations were found that result in failure to release protein from the membrane into the periplasmic space of Salmonella typhimurium after removal of the signal peptide. The mutant protein is found in a membrane-bound form accessible to trypsin added to intact spheroplasts. The phenotype of these mutations supports the existence in general of an intermediate...

Many workers on the subject of pteroylglutamic-acid (PGA) deficiency in the rat have obtained data about the requirement of the rat for this vitamin; but so far the emphasis has been on the therapeutic dose required to correct a given deficiency rather than on the amount necessary for maintenance. Figures for the normal requirement are needed as a guide in the preparation of certain purified di...

tumor necrosis factor-related apoptosis-inducing ligand (trail), a member of tnf family, is an interesting ligand which selectively induces apoptosis in tumor cells and, therefore, it has been developed for cancer therapy. this ligand has been produced by various hosts such as e.coli. however, protein expression in e.coli cytoplasm leads to problems such as incorrect folding, reduction in biolo...

High-pressure freezing of Escherichia coli K-12 and Pseudomonas aeruginosa PAO1 in the presence of cryoprotectants provided consistent vitrification of cells so that frozen-hydrated sections could be cut, providing approximately 2-nm resolution of structure. The size and shape of the bacteria, as well as their surface and cytoplasmic constituents, were nicely preserved and compared well with ot...

The 5'-nucleotidase of Escherichia coli was shown to be located at the cell wall surface by histochemical techniques utilizing the deposition of inorganic phosphate. Penetration of the 5'-nucleotidase in the periplasmic space was seen only in cells treated with ethylenediaminetetraacetic acid (EDTA)-tris(hydroxymethyl)aminomethane (Tris). The 3'-nucleotidase of E. coli was also found to have a ...