Metal-dependent allosteric activation and inhibition on the same molecular scaffold: the copper sensor CopY from .

Resistance to copper (Cu) toxicity in the respiratory pathogen is regulated by the Cu-specific metallosensor CopY. CopY is structurally related to the antibiotic-resistance regulatory proteins MecI and BlaI from , but is otherwise poorly characterized. Here we employ a multi-pronged experimental strategy to define the CopY coordination chemistry and the unique mechanism of allosteric activation by Zn(ii) and allosteric inhibition by Cu(i) of promoter DNA binding.

Cooperative Formation of Icosahedral Proline Clusters from Dimers.

Ion mobility spectrometry-mass spectrometry and Fourier transform infrared spectroscopy (FTIR) techniques were combined with quantum chemical calculations to examine the origin of icosahedral clusters of the amino acid proline. When enantiopure proline solutions are electrosprayed (using nanospray) from 100 mM ammonium acetate, only three peaks are observed in the mass spectrum across a concentration range of five orders of magnitude: a monomer [Pro+H] species, favored from 0.001 to 0.

Word2Vec inversion and traditional text classifiers for phenotyping lupus.

Background: Identifying patients with certain clinical criteria based on manual chart review of doctors' notes is a daunting task given the massive amounts of text notes in the electronic health records (EHR). This task can be automated using text classifiers based on Natural Language Processing (NLP) techniques along with pattern recognition machine learning (ML) algorithms. The aim of this research is to evaluate the performance of traditional classifiers for identifying patients with Systemic Lupus Erythematosus (SLE) in comparison with a newer Bayesian word vector method.

Resolution of Stepwise Cooperativities of Copper Binding by the Homotetrameric Copper-Sensitive Operon Repressor (CsoR): Impact on Structure and Stability.

The cooperativity of ligand binding is central to biological regulation and new approaches are needed to quantify these allosteric relationships. Herein, we exploit a suite of mass spectrometry (MS) experiments to provide novel insights into homotropic Cu-binding cooperativity, gas-phase stabilities and conformational ensembles of the D2 -symmetric, homotetrameric copper-sensitive operon repressor (CsoR) as a function of Cu(I) ligation state. Cu(I) binding is overall positively cooperative, but is characterized by distinct ligation state-specific cooperativities.

Detection of the Duquenois-Levine chromophore in a marijuana sample.

The Duquenois-Levine test for tetrahydrocannabinol (THC) has been used in the forensic science community for over 80 years. This three-part color test is one of many tests used to confirm the presence of THC. In recent years, there have been accusations that this test is not specific enough to use as the sole means of conviction and there is no proof the color produced is from the presence of THC.