Profiling the chemistry- and confinement-controlled sensing capability of an octameric aerolysin-like protein.

Octameric Aep1 was employed, for the first time to the best of our knowledge, as a nanopore to expand applications. After investigating the optimized conditions of Aep1 for single-channel recording, the sensing features were characterized. Cyclic and linear molecules of varying sizes and charges were employed to probe the radius and chemical environment of the pore, providing deep insights for expected future endeavors at predicting the structure of octameric Aep1. γ-CD showed unique suitability as an 8-subunit adapter in octameric Aep1, enabling the discrimination of ß-nicotinamide mononucleotide.

3D Blockage Mapping for Identifying Familial Point Mutations in Single Amyloid-ß Peptides with a Nanopore.

Accurate discrimination of amyloid-ß (Aß) peptides containing familial point mutations would advance the knowledge of their roles in early-onset Alzheimer's disease. Herein, we simultaneously identified the mutant A21G, E22G, E22Q, and the wild-type (WT) Aß18-26 peptides with aerolysin nanopore using a 3D blockage mapping strategy. The standard deviation of current blockade fluctuations (σb ) was proposed as a new supplement to current blockage (Ib /I0 ) and duration time (tD ) to profile the blockage characteristics of single molecules. Although the WT and A21G Aß18-26 are indistinguishable in a traditional Ib /I0 -tD 2D description, ∼87 % of the blockade events can be accurately classified with half reduction of false identification using a combination of Ib /I0 , tD, and σb . This work offers an easy and reliable strategy to promote nanopore sensitivity of peptide mutants, leading to a more precise analysis of pathogenic mutations for developing effective diagnosis and treatment.

Full Width at Half Maximum of Nanopore Current Blockage Controlled by a Single-Biomolecule Interface.

A biological nanopore is one of the predominant single-molecule approaches as a result of its controllable single-biomolecule interface, which could reflect the "intrinsic" information on an individual molecule in a label-free way. Because the current blockage is normally treated as the most important parameter for nanopore identification of every single molecule, the fluctuation of current blockage for certain types of molecules, defined as full width at half maximum (fwhm) of current blockage, actually owns a dominant influence on nanopore resolution. Therefore, controlling the fwhm of current blockage of molecules is critical for the sensing capability of the nanopore. Here, taking an aerolysin nanopore as a model, by precisely controlling the functional group in this single-biomolecule interface, we could narrow the fwhm of nanopore current blockage for DNA identification and prolong the duration inside the nanopore. Moreover, a substantial correlation between fwhm of current blockage and duration is established, showing a non-monotonic variation. Besides, the mechanism is also clarified with studying the detailed current blockage events. This proposed correlation is further demonstrated to be applied uniformly across different mutant aerolysins for a certain DNA. This study proposes a new strategy for regulating molecular sensing from the duration of the analyte, which could guide the resolution of heterogeneity analysis using nanopores.

Pharmacokinetic and pharmacodynamic analysis of ferulic acid-puerarin-astragaloside in combination with neuroprotective in cerebral ischemia/reperfusion injury in rats

OBJECTIVE@#To investigate the effects of the active ingredients combined therapy on inflammatory factors interleukin 1 beta (IL-1β) and neuropeptide Y (NPY) based on pharmacodynamics in rats.@*METHODS@#The animal model was built by transient middle cerebral artery occlusion (MCAO). The method for evaluating the concentrations of the FA-Pr-Al components in rat plasma was established by using HPLC and the expression levels of IL-1β and NPY were determined by ELISA. A new mathematics method of the trend of percentage rate of change (PRC) was used to assess the correlation between pharmacokinetics (PK) and pharmacodynamics (PD).@*RESULTS@#FA-Pr-Al in combination reduced neurological deficits, decreased infarct volume and inhibited the expression levels of IL-1β and NPY (all P<0.05) compared with the model group. FA, Pr and Al all displayed two compartment open models in rats. Clockwise hysteresis loops were obtained by time-concentration-effect curves. IL-1β and NPY level changes in the plasma followed an opposite trend to the plasma concentration tendency after Cmax was reached. Astragaloside's PRC value was significantly higher than those of FA and puerarin between 120 to 180 min.@*CONCLUSIONS@#The pharmacokinetics of FA-Pr-Al in combination were closely related its pharmacodynamics in treating ischemia/reperfusion injury, and the components of FA-Pr-Al may have a synergistic pharmacological effect. Astragaloside may play a more pronounced role in regulating IL-1βand NPY levels compared with puerarin or FA.

Pharmacokinetic and pharmacodynamic analysis of ferulic acid-puerarin-astragaloside in combination with neuroprotective in cerebral ischemia/reperfusion injury in rats

Objective: To investigate the effects of the active ingredients combined therapy on inflammatory factors interleukin 1 beta (IL-1β) and neuropeptide Y (NPY) based on pharmacodynamics in rats. Methods: The animal model was built by transient middle cerebral artery occlusion (MCAO). The method for evaluating the concentrations of the FA-Pr-Al components in rat plasma was established by using HPLC and the expression levels of IL-1β and NPY were determined by ELISA. A new mathematics method of the trend of percentage rate of change (PRC) was used to assess the correlation between pharmacokinetics (PK) and pharmacodynamics (PD). Results: FA-Pr-Al in combination reduced neurological deficits, decreased infarct volume and inhibited the expression levels of IL-1β and NPY (all Pmax was reached. Astragaloside's PRC value was significantly higher than those of FA and puerarin between 120 to 180 min. Conclusions: The pharmacokinetics of FA-Pr-Al in combination were closely related its pharmacodynamics in treating ischemia/reperfusion injury, and the components of FA-Pr-Al may have a synergistic pharmacological effect. Astragaloside may play a more pronounced role in regulating IL-1βand NPY levels compared with puerarin or FA.

Study on transport of Yangyin Tongnao granules in main effective fractions / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the absorption characteristics and transportation mechanism Yangyin Tongnao granules in main effective fractions in Caco-2 cell model.</p><p><b>METHOD</b>The safety concentrations of Yangyin Tongnao granules in main effective fractions in Caco-2 cells. A Caco-2 cell model was established to study the transport situations after the compatibility of Yangyin Tongnao granules in main effective fractions, and the content was determined by high performance liquid chromatography (HPLC).</p><p><b>RESULT</b>P(app) of puerarin, ligustrazine and astragaloside were less than 1.0 x 10(-6) cm x s(-1), and their P(app) were hard to be close to atenolol. The oral absorption in descending order is shown as the following: puerarin, ligustrazine, astragaloside. After the compatibility between saponins and flavonoids, P(app) of astragaloside was improved obviously, which promoted the transport from apical (AP) to basolateral (BL); the compatibility of puerarin, ligustrazine and astragaloside showed a significant effect in the efflux of astragaloside and no change in the absorption transport of ligustrazine and puerarin at the same time. There is a great difference in bidirectional transport of representative component of each effective fraction, and P(app)(B --> A) was significantly greater than Papp(A --> B), which suggested that the efflux transport from BL side to AP side had an advantage in the three representative components of the three effective fractions in Caco-2 cell monolayer model.</p><p><b>CONCLUSION</b>Astragaloside, ligustrazine and puerarin may be malabsorptive compounds, and the three compounds may be discharged by the transport protein in small intestine membrane.</p>