CRP Binding Kinetics Enhancement Using Local Narrowing into a Bent Channel: Finite Element Analysis

Binding kinetics enhancement of a microfluidic biosensor into a micro-channel through the application of a supplementary mechanism has received tremendous attention because of the obtained significant enhancement factor. However, biosensor’s performance enhancement using only simple channel engineering is still rarely realized. Herein, we present a novel design of a complex reactive protein (CRP) biosensor into a U-shaped channel with a sensitive membrane located in the middle of the bent zone. Various critical factors affecting the equilibrium binding time are numerically investigated. The turn geometry is then optimized when the arc length along the inner and outer radii is almost the same, which leads to locally minimizing the channel height overhead the reaction surface and improves the analyte transport towards the sensing area. The numerical studies reveal that applying a local narrowing above the reaction surface can notably enhance the trapping and the surface formation of complex antibody-antigen, thus upgrading the biosensor performance. This work puts a significant advance towards microfluidic channel engineering and the exploration of micro-flow injection experimental studies.

Study on the Interaction between Human Serum Albumins and Methyl Pheophorbide-a-Gd

The binding reaction between methyl pheophorbide-a-Gd (MPA-Gd) and Human Serum Albumins (HSA) was studied by fluorescence and UV-Vis absorption spectra. The results indicated that the binding reaction of them was a single static quenching process, MPA-Gd strongly bound HSA, the binding equilibrium constant K0=2.298×105 L·mol-1 at 25 ℃. The shortest binding distance(r) and energy transfer efficiency(E) between donor (HSA) and acceptor (MPA-Gd) was obtained by Frster′s nonradiative energy transfer mechanism as follows: r=4.03 nm, E=0.12. The enthalpy change (ΔH) and entropy change (ΔS) were calculated at 25 and 37 ℃. The results indicated that the hydrogen bonds played major role in the reaction. Furthermore, the displacement experiments indicated that MPA-Gd could bind to the site Ⅱof HSA.

Voltammetric Determination of Heparin Based on Its Interaction with Brilliant Cresyl Blue

Heparin is a polysaccharide of glycosaminoglycan class, which consists of repeating disaccharide units of iduronic/glucuronic acid and glucosamine residues with many biological functions. Many methods have been proposed for the detection of heparin, including UV-Vis spectrophotometry, the light scattering technique, HPLC and electro phoresis and flow injection analysis, etc.. But there are few reports about the detection of heparin by means of an electrochemical method. Electroanalytical methods are useful tools in bioanalytical chemistry because of their advantages, such as their instrumental simplicity, moderate cost and portability. The binding reactions of organic molecules with biomolecules such as DNA and proteins have been widely studied. In acidic solution, heparin is highly negatively charged due to the dissociation of the sulfate and carboxyl groups in its molecule, which can easily interact with cationic dyes. Based on this principle, in this work, a new electrochemical method for the determination of heparin was developed based on the interaction of heparin with brilliant cresyl blue（BCB）.

High expression of RbAp46 gene in patients with acute leukemia or chronic myelogenous leukemia in blast crisis

The retinoblastoma （Rb） suppressor associated protein 46 （ RbAp46 ） also named retinoblastoma binding protein 7 （RBBP7） was first identified as a protein in HeLa cells that binds to an Rb affinity column. RbAp46 has been shown to be a core component of the mSin3 histone deacetylase （HDAC） complex and NuRD （ a multi-subunit complex containing chromosome-remodeling activity）. 2 RbAp46 is also known as the histone acetyltransferase （HAT） type B subunit