Adsorption/Desorption Transition of RecombinantHumanNeurotrophin4: Physicochemical Characterization.
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Bulk physicochemical properties neurotrophin 4 (NT- 4 ) in the electrolyte solution and the adsorption / desorption on / from the mica surface has been studied by using dynamic scattering light (DLS), microelectrophoresis, depletion engineering solution (enzyme-linked immunosorbent assay, ELISA), and AFM imaging. Our study presents the determination of diffusion coefficients, hydrodynamic diameter, electrophoretic mobility and isoelectric point of NT- 4 under various ionic strength and pH conditions.
The size of NT- 4 homodimer to the ionic strength of 0.015 M is substantially independent of pH and equal to 5.1 nm. It has been found that the total cost of the electrokinetic per NT- 4 molecule is equal to zero for all ionic strengths studied at pH 8.1, which was identified as the isoelectric point (IEP). Protein adsorption / desorption on / from the mica surface was examined as a function of the ionic strength and pH. Kinetics neurotrophin the adsorption / desorption evaluated at pH 3.5, 7. 4 , and 11 by direct AFM imaging and ELISA techniques.
Increased monotonous in maximum coverage absorbed NT- 4 molecules with ionic strength (up to 5.5 mg / m2) was observed at pH 3.5. These results are interpreted in terms of theoretical models postulated an irreversible adsorption of proteins regulated by random sequential adsorption (RSA). Our measurements show the important role of the ionic strength, pH, and the composition of the electrolyte in the lateral electrostatic interactions between charged different NT- 4 molecule. The transition between the adsorption / desorption was found to area high pH and low surface concentration of adsorbed neurotrophin molecules at constant ionic strength.
In addition, the results presented in this work show that the adsorption behavior of neurotrophin molecules can be regulated by electrostatic interactions intrasolvent produce aggregation process. polyvalent understanding of neurotrophin interaction may affect the reversibility / irreversibility of the adsorption, and therefore they may be useful to obtain a protein coating that is ordered, targeting the future development of drug delivery systems to treat neurodegenerative diseases.
Adsorption/Desorption Transition of RecombinantHumanNeurotrophin4: Physicochemical Characterization.
Over-expression of neurotrophin 3 in human aortic valve calcification disease affected induce osteogenic response through Trk-Akt pathway.
Calcific aortic valve disease (CAVD) is a leading cardiovascular disorders in the elderly. While the aortic valve interstitial cells (AVICs) are master cells that express osteogenic mediator, the molecular mechanisms that mediate osteogenic response AVIC is not fully understood. The purpose of this study to identify the factors pro-osteogenic in human AVICs influenced by CAVD.
RESULTS Microarray analysis identified 11 genes up-regulated in diseased valve AVICs. Among these genes, mRNA levels of neurotrophin 3 (NT3) increased by 2-fold. a higher level of NT3 protein in diseased aortic valve and AVICs illness confirmed by immunofluorescent staining and immunoblotting, respectively. Exposure AVICs normal valve recombinant human NT3 (0.025-0.10μg / ml) up-regulated the production of Runx2, TGF-β1 and BMP-2 in a dose-dependent fashion.
NT3 also promote the formation of calcium deposits. Pro-osteogenic effect of the NT3 is not affected by the neutralization of the Toll-like receptor 2 or 4. Interestingly, mRNA that encodes nerve growth factor receptor (TrkA, TrkB, TrkC and p75 NTR) AVICs detected in humans.
Description: Neurotrophin-4 Human Recombinant produced in E.Coli is a noncovalently linked homodimer, non-glycosylated polypeptide chain containing 2 x 130 amino acids (81-210 amino acids) and having a total molecular mass of 28 kDa. ;The NT-4 is purified by proprietary chromatographic techniques.
Trk receptor inhibition markedly reduces the effect of NT3 on Runx2, TGF-β1 and the production of BMP-2, the formation of calcium deposits and Akt phosphorylation. Furthermore, inhibition of Akt also reduces pro-osteogenic effect of NT3.
