Resolution of Maximum Entropy Method-Derived Posterior Conformational Ensembles of a Flexible System Probed by FRET and Molecular Dynamics Simulations.

Maximum entropy methods (MEMs) determine posterior distributions by combining experimental data with prior information. MEMs are frequently used to reconstruct conformational ensembles of molecular systems for experimental information and initial molecular ensembles. We performed time-resolved Förster resonance energy transfer (FRET) experiments to probe the interdye distance distributions of the lipase-specific foldase Lif in the state, which likely has highly flexible, disordered, and/or ordered structural elements.

Combined nerve and vascular ultrasound in thoracic outlet syndrome: A sensitive method in identifying the site of neurovascular compression.

We investigated the diagnostic utility of combined nerve and vascular ultrasound in thoracic outlet syndrome (TOS) in a retrospective cohort study on two sites, involving 167 consecutive patients with the clinical symptoms suggestive of neurogenic and/or vascular TOS, and an age- and sex-matched control group. All patients and control subjects underwent nerve ultrasound of the supraclavicular brachial plexus to look for fibromuscular anomalies / compression of the brachial plexus in the scalenic region, and vascular ultrasound of the infraclavicular subclavian artery with the arm in neutral and abducted position, serving as an indicator for costoclavicular compression of the neurovascular bundle. Based on clinical symptoms, neurogenic TOS (81%) was the most frequent type of TOS, followed by combined neurogenic and arterial TOS (8%).

Structural and dynamic insights revealing how lipase binding domain MD1 of Pseudomonas aeruginosa foldase affects lipase activation.

Folding and cellular localization of many proteins of Gram-negative bacteria rely on a network of chaperones and secretion systems. Among them is the lipase-specific foldase Lif, a membrane-bound steric chaperone that tightly binds (K = 29 nM) and mediates folding of the lipase LipA, a virulence factor of the pathogenic bacterium P. aeruginosa.

The Membrane-Integrated Steric Chaperone Lif Facilitates Active Site Opening of Pseudomonas aeruginosa Lipase A.

Lipases are essential and widely used biocatalysts. Hence, the production of lipases requires a detailed understanding of the molecular mechanism of its folding and secretion. Lipase A from Pseudomonas aeruginosa, PaLipA, constitutes a prominent example that has additional relevance because of its role as a virulence factor in many diseases.

Directed evolution of Gloeobacter violaceus rhodopsin spectral properties.

Proton-pumping rhodopsins (PPRs) are photoactive retinal-binding proteins that transport ions across biological membranes in response to light. These proteins are interesting for light-harvesting applications in bioenergy production, in optogenetics applications in neuroscience, and as fluorescent sensors of membrane potential. Little is known, however, about how the protein sequence determines the considerable variation in spectral properties of PPRs from different biological niches or how to engineer these properties in a given PPR.