Assessing anesthetic activity through modulation of the membrane dipole potential.

There is great individual variation in response to general anesthetics (GAs) leading to difficulties in optimal dosing and sometimes even accidental awareness during general anesthesia (AAGA). AAGA is a rare, but potentially devastating, complication affecting between 0.1% and 2% of patients undergoing surgery.

Aetiology of hospital-acquired pneumonia and trends in antimicrobial resistance.

Purpose Of Review: Hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) continue to present very significant diagnostic and management challenges. The development, introduction and use of a wider range of immunosuppressive therapies are leading to a broader spectrum of microorganisms causing HAP and VAP. The persistent clinical dilemma regarding their cause is that detection of a microorganism from a respiratory tract sample does not necessarily signify it is the causative agent of the pneumonia.

The respiratory complexes I from the mitochondria of two Pichia species.

NADH:ubiquinone oxidoreductase (complex I) is an entry point for electrons into the respiratory chain in many eukaryotes. It couples NADH oxidation and ubiquinone reduction to proton translocation across the mitochondrial inner membrane. Because complex I deficiencies occur in a wide range of neuromuscular diseases, including Parkinson's disease, there is a clear need for model eukaryotic systems to facilitate structural, functional and mutational studies.

Altering the ribosomal subunit ratio in yeast maximizes recombinant protein yield.

Background: The production of high yields of recombinant proteins is an enduring bottleneck in the post-genomic sciences that has yet to be addressed in a truly rational manner. Typically eukaryotic protein production experiments have relied on varying expression construct cassettes such as promoters and tags, or culture process parameters such as pH, temperature and aeration to enhance yields. These approaches require repeated rounds of trial-and-error optimization and cannot provide a mechanistic insight into the biology of recombinant protein production.

The Redox-Bohr group associated with iron-sulfur cluster N2 of complex I.

Proton pumping respiratory complex I (NADH:ubiquinone oxidoreductase) is a major component of the oxidative phosphorylation system in mitochondria and many bacteria. In mammalian cells it provides 40% of the proton motive force needed to make ATP. Defects in this giant and most complicated membrane-bound enzyme cause numerous human disorders.

Application of the yeast Yarrowia lipolytica as a model to analyse human pathogenic mutations in mitochondrial complex I (NADH:ubiquinone oxidoreductase).

While diagnosis and genetic analysis of mitochondrial disorders has made remarkable progress, we still do not understand how given molecular defects are correlated to specific patterns of symptoms and their severity. Towards resolving this dilemma for the largest and therefore most affected respiratory chain enzyme, we have established the yeast Yarrowia lipolytica as a eucaryotic model system to analyse respiratory chain complex I. For in vivo analysis, eYFP protein was attached to the 30-kDa subunit to visualize complex I and mitochondria.

Functional significance of conserved histidines and arginines in the 49-kDa subunit of mitochondrial complex I.

We have studied the ubiquinone-reducing catalytic core of NADH:ubiquinone oxidoreductase (complex I) from Yarrowia lipolytica by a series of point mutations replacing conserved histidines and arginines in the 49-kDa subunit. Our results show that histidine 226 and arginine 141 probably do not ligate iron-sulfur cluster N2 but that exchanging these residues specifically influences the properties of this redox center. Histidines 91 and 95 were found to be essential for ubiquinone reductase activity of complex I.