Determinants of translocation and folding of TreF, a trehalase of Escherichia coli

One isoform of trehalase, TreF, is present in the cytoplasm and a second, TreA, in the periplasm. To study the questions of why one enzyme is exported efficiently and the other is not and whether these proteins can fold in their nonnative cellular compartment, we fused the signal sequence of periplasmic TreA to cytoplasmic TreF. Even though this TreF construct was exported efficiently to the periplasm, it was not active. It was insoluble and degraded by the periplasmic serine protease DegP. To determine why TreF was misfolded in the periplasm, we isolated and characterized Tre+ revertants of periplasmic TreF. To further characterize periplasmic TreF, we used a genetic selection to isolate functional TreA-TreF hybrids, which were analyzed with respect to solubility and function. These data suggested that a domain located between residues 255 and 350 of TreF is sufficient to cause folding problems in the periplasm. In contrast to TreF, periplasmic TreA could fold into the active conformation in its nonnative cellular compartment, the cytoplasm, after removal of its signal sequence

Clinical efficacy of a dry extract of five herbal drugs in acute viral rhinosinusitis

Objective: A herbal drug combination (Dry Extract BNO 1016) has been assessed for efficacy and tolerability in patients with acute viral rhinosinusitis. Methodology: In this randomised, controlled trial patients with symptom duration of days, mild to moderate facial pain and a Major Symptom Score (MSS) of >= 8 and <= 12 were treated for 15 days with BNO 1016 or placebo (coated tablets administered orally). Primary efficacy endpoint was mean MSS at end of treatment. Secondary outcome measures included treatment response and changes in paranasal sinuses assessed by ultrasonography. Results:Treatment resulted in clinically relevant, significant differences in mean MSS for BNO 1016 versus placebo. BNO 1016 provided symptom relief two days earlier than placebo. The number needed to treat for healing is 8. BNO 1016 was superior regarding responder rates at Day 10 and Day 14 and percentage of patients without signs of acute viral rhinosinusitis assessed by ultrasonography at end of treatment. BNO 1016 was well tolerated; no serious adverse events were reported. Conclusion: The herbal dry extract BNO 1016 is efficacious and well tolerated in patients with acute viral rhinosinusitis

Is the In Vitro Ejection of Bacteriophage DNA Quasistatic? A Bulk to Single Virus Study

Bacteriophage T5 DNA ejection is a complex process that occurs on several timescales in vitro. By using a combination of bulk and single phage measurements, we quantitatively study the three steps of the ejection—binding to the host receptor, channel-opening, and DNA release. Each step is separately addressed and its kinetics parameters evaluated. We reconstruct the bulk kinetics from the distribution of single phage events by following individual DNA molecules with unprecedented time resolution. We show that, at the single phage level, the ejection kinetics of the DNA happens by rapid transient bursts that are not correlated to any genome sequence defects. We speculate that these transient pauses are due to local phase transitions of the DNA inside the capsid. We predict that such pauses should be seen for other phages with similar DNA packing ratios