Rapid and highly sensitive pathogen detection by real-time DNA monitoring using a nanogap impedimetric sensor with recombinase polymerase amplification.

Fast detection of pathogens is important for protecting our health and society. Herein, we present a high-performance nanogap impedimetric sensor for monitoring nucleic acid amplification in real time using isothermal recombinase polymerase amplification (RPA) for rapid pathogen detection. The nanogap electrode chip has two pairs of opposing gold electrodes with a 100 nm gap and was fixed to a PCB. Then, the nanogap impedimetric sensor was immersed in RPA reaction solution for the detection of E. coli O157:H7, and target DNA amplification was evaluated through bulk solution impedance changes using impedance spectroscopy every minute during RPA. In addition, target gene amplification in the sample solution during RPA was confirmed with a 2% DNA agarose gel. Our nanogap impedimetric sensor can detect down to a single copy of the eae A gene in gDNA extracted from E. coli O157:H7 as well as a single cell of pathogenic E. coli O157:H7 strain within 5 min during direct RPA, which was performed with the pathogen itself and without the extraction and purification of target gDNA. The miniaturized nanogap impedimetric sensor has potential as a cost-effective point-of-care device for fast and accurate portable pathogen detection via real-time nucleic acid analysis.

Identification of novel inhibitors of extracellular signal-regulated kinase 2 based on the structure-based virtual screening.

Extracellular signal-regulated kinase 2 (ERK2) has become an attractive target for the development of therapeutics for the treatment of cancer. We have been able to identify eight new inhibitors of ERK2 by means of a drug design protocol involving the virtual screening with docking simulations and in vitro enzyme assay. The newly discovered inhibitors can be categorized into three structural classes and reveal a significant potency with IC(50) values ranging from 1 to 30 microM. Therefore, all of the three inhibitor scaffolds deserve further development by structure-activity relationship or de novo design methods. Structural features relevant to the stabilizations of the newly identified inhibitors in the ATP-binding site of ERK2 are discussed in detail.