An approximation to the identification of contexts, experiences, and profiles of victims of drug-facilitated sexual assaults

This study advances on overcoming a bias limiting the forensic cases studies of drug-facilitated sexual assaults: a narrow study focus, restricted to assaults affecting young women in leisure contexts related to nightlife, party culture, and dating. A new working framework is applied to analyse data from cases received in the National Institute of Toxicology and Forensic Sciences (Madrid, Spain) over the six years between 2012 and 2017. The work throws light on non-previously described contexts, experiences, and profiles of victims, including domestic cohabitation, labour, education, healthcare, women trafficking, and the daily life of people with intellectual disabilities.Ministerio de Sanidad (Delegación del Gobierno para el Plan Nacional sobre Drogas) e Instituto Universitario de Investigación en Ciencias Policiales (UAH, IUICP

Helix propensities of conformationally restricted amino acids. Non-natural substitutes for helix breaking proline and helix forming alanine

Alpha helices are useful scaffolds to build biologically active peptides. The intrinsic stability of an alpha-helix is a key feature that can be successfully designed, and it is governed by the constituting amino acid residues. Their individual contributions to helix stability are given, according to Lifson–Roig theory, by their w parameters, which are known for all proteinogenic amino acids, but not for non-natural ones. On the other hand, non-natural, conformationally-restricted amino acids can be used to impart biochemical stability to peptides intended for in vivo administration. Efficient design of peptides based on these amino acids requires the previous determination of their w parameters. We begin here this task by determining the w parameters of two restricted analogs of alanine: (α-methyl)alanine and 1-aminocyclopropanecarboxylic acid. According to their w values (α-methyl)alanine is almost as good a helix forming residue as alanine, while 1-aminocyclopropanecarboxylic acid is, similarly to proline, a helix breaker.We acknowledge financial support from grants: BFU2007- 61476/BMC and CTQ2007-62245 (Spain); PM048/2004 and PI078/08 (Gobierno de Aragón, Spain).Peer Reviewe

Optimization of a rapid method for screening drugs in blood by liquid chromatography tandem mass spectrometry

In the recent years, liquid chromatography with tandem mass spectrometry has gained popularity in laboratories. This technique has a higher specificity, detects different analytes from a single specimen, measures analytes in distinct matrices, and substantially reduce analytical interference, with respect to immunoassay. The processing and preparation of biological samples are crucial in chromatography. Interferences in blood testing are usually caused by the presence of phospholipids and proteins. The main objective of this study was to improve analytical processes for drug screening by LC-MS/MS using a novel blood sample preparation method based on protein precipitation and removal of phospholipids

Optimización de un método de cribado rápido de fármacos en sangre mediante la técnica de cromatografía de líquidos acoplada a espectrometría de masas

La cromatografía líquida acoplada a la espectrometría de masas ha ganado en popularidad en los laboratorios en los últimos años debido a una mayor especificidad de la técnica, la posibilidad de determinar múltiples analitos en una sola inyección de la muestra, la medición de analitos en una variedad de matrices diferentes y a una drástica reducción de las interferencias analíticas en comparación con el inmunoensayo. El tratamiento y preparación de las muestras biológicas es un proceso esencial cuando éstas han de ser analizadas mediante sistemas cromatográficos. Los principales interferentes en el análisis de las muestras de sangre son los fosfolípidos y las proteínas. El objetivo principal de este estudio es mejorar la sistemática analítica toxicológica en el cribado general de fármacos mediante la técnica LC-MS/MS a través de un nuevo método de preparación de muestras en sangre basado en la precipitación de proteínas y eliminación de fosfolípidos

Difining the Nature of Thermal Intermediate in 3 State Folding Proteins: Apoflavodoxin, a Study Case

The early stages of the thermal unfolding of apoflavodoxin have been determined by using atomistic multi microsecond-scale molecular dynamics (MD) simulations complemented with a variety of experimental techniques. Results strongly suggest that the intermediate is reached very early in the thermal unfolding process and that it has the properties of an"activated" form of the native state, where thermal fluctuations in the loops break loop-loop contacts. The unrestrained loops gain then kinetic energy corrupting short secondary structure elements without corrupting the core of the protein. The MD-derived ensembles agree with experimental observables and draw a picture of the intermediate state inconsistent with a well-defined structure and characteristic of a typical partially disordered protein. Our results allow us to speculate that proteins with a well packed core connected by long loops might behave as partially disordered proteins under native conditions, or alternatively behave as three state folders. Small details in the sequence, easily tunable by evolution, can yield to one or the other type of proteins

Major clusters obtained (cluster radii 2.5 Å; see Methods) from the meta-trajectory of apoflavodoxin at room temperature.

<p>The typical secondary structure content of each of cluster is shown, with the X-ray structure as reference.</p

Cross-root mean square deviation plot for the 2 µsec unfolding simulation of apoflavodoxin at 368 K (RMSd color code is in Å).

<p>The central structure of the different clusters (cluster radii 4.6 Å) sampled during the trajectories are projected into the cross RMSd plot. The typical secondary structure content of the structures in the different clusters is shown with a reference to X-Ray structure (PDB code 1FTG).</p

B-factors profile (Å) for apoflavodoxin obtained from simulations:

<p>i) the control meta-trajectory at 300 K, ii) the large unfolding trajectory at 368 K, iii) the meta-trajectory at 368 K and iv) the profile reported in the crystal structure (PDB code 1FTG).</p

Evolution of different metrics along the 2 µsec unfolding simulation of apoflavodoxin at 368 K.

<p>TOP/LEFT: All atoms root mean square deviation and TM-score from crystal structure (both in Å). TOP/RIGHT: Radii of gyration (in Å). BOTTOM/LEFT: content of secondary structure. BOTTOM/RIGHT Solvent accessible surface (total, hydrophobic and hydrophilic, all in Ų). Reference lines represent always the values found in the crystal structure (PDB code 1FTG).</p

Histogram representation of the distributions of “experimental observables” obtained from the different clusters.

<p>From TOP to BOTTOM: fitting to SAXs curve, Φ-value error and Trp solvent accessible surface (see text and <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1002647#pcbi-1002647-g006" target="_blank">Figure 6</a> for details).</p