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991.
The human leukocyte elastase (HLE), a neutrophil serine protease of the chymotrypsin superfamily, is a major therapeutic target for a number of inflammatory diseases, such as chronic obstructive pulmonary disease (COPD). In this work, we present a comparative explicit water molecular dynamics (MD) study on the free and inhibitor-bound HLE. Knowledge of the flexibility and conformational changes induced by this irreversible inhibitor, whether in a prebound stage or covalently bound at the enzyme binding site, encases fundamental biological interest and is particularly relevant to ongoing structure-based drug design studies. Our results suggest that HLE operates by an induced-fit mechanism with direct intervention of a surface loop which is open toward the solvent in the free enzyme and closed while in the presence of the ligand. MM-PBSA free energy calculations furthermore elucidate the energetic contributions to the distinct conformations adopted by this loop. Additionally, a survey of the major contributions to the inhibitor binding free energies was attained. Our findings enforce the need to account for HLE flexibility, whether through the use of MD-generated ensembles of HLE conformations as targets for molecular docking or via sophisticated flexible-docking algorithms. We anticipate that inclusion of the observed HLE dynamic behavior into future drug design methodologies will have a relevant impact in the development of novel, more efficient, inhibitors. 相似文献
992.
Surfactant-free gelatin/heptamolybdate (HM) hybrid nanoparticles are prepared by a simple and environmentally friendly approach utilizing the electrostatic interaction between anionic HM and the zwitterionic gelatin. The obtained nanoparticles have a tunable size and very high HM loading content up to about 70%. In vitro and in vivo experiments prove that the gelatin/HM hybrid nanoparticles exhibit significantly better antitumor activity than plain ammonium heptamolybdate solution. Therefore, the gelatin/HM hybrid nanoparticles reported here may serve as a prototype platform for polymer/polyoxometalate (POM) hybrid nanoparticles as cancer treatment agents and hence open up more opportunities to maximize the potential of POM-based pharmaceutical agents. 相似文献
993.
Chiono V Sartori S Rechichi A Tonda-Turo C Vozzi G Vozzi F D'Acunto M Salvadori C Dini F Barsotti G Carlucci F Burchielli S Nicolino S Audisio C Perroteau I Giusti P Ciardelli G 《Macromolecular bioscience》2011,11(2):245-256
A biocompatible and elastomeric PU was synthesized from low-molecular-weight PCL as macrodiol, CMD as chain extender and HDI as chain linker for applications in the field of peripheral nerve repair. PU cast films supported in vitro attachment and proliferation of NOBEC. The in vitro adhesion and proliferation of S5Y5 neuroblastoma cells on the inner surface of uncoated, gelatin- and PL-coated PU guides were compared. Due to their superior in vitro performance, PL-coated PU guides were tested in vivo for the repair of 1.8 cm-long defects in rat sciatic nerves. The progressive regeneration was confirmed by EMG and histological analysis showing the presence of regenerating fibers in the distal stumps. 相似文献
994.
Martins A Alves da Silva ML Faria S Marques AP Reis RL Neves NM 《Macromolecular bioscience》2011,11(7):978-987
A specially designed electroconductive collector enables the electrospinning of P-NFM composed of areas of parallel/uniaxially aligned fibers and areas of random/orthogonal nanofiber distribution. The biological relevance of P-NFM is demonstrated using hBMSCs as an autologous cell source. The structures induce cell orientation along the uniaxially aligned fibers, mainly during earlier culturing periods under basal and osteogenic differentiation conditions. The microtopography of the P-NFM also controls the deposition of mineralized extracellular matrix along the pre-defined fiber direction. Genotypic characterization confirms the successful differentiation into the osteogenic lineage. 相似文献
995.
von Vacano B Xu R Hirth S Herzenstiel I Rückel M Subkowski T Baus U 《Analytical and bioanalytical chemistry》2011,400(7):2031-2040
By combining several surface analytical tools, we show that an adsorbed layer of the protein H*Protein B prevents the adsorption
of secondary proteins bovine serum albumin, casein, or collagen at low-salinity conditions and at pH 8. H*Protein B is an
industrially producible fusion protein of the hydrophobin family, known for its high interfacial activity. While applications
of hydrophobin have been reported to facilitate adhesion of proteins under different pH conditions, careful analysis by quartz-crystal
microbalance and ellipsometry prove that no additional adsorption can be found on top of the H*Protein B layer in this study.
Surface analysis by X-ray photoelectron spectroscopy and secondary ion mass spectrometry proves that the hydrophobin layer
stays intact even after hours of exposure to solutions of the secondary proteins and that no exchange of proteins can be detected. 相似文献
996.
997.
A photopolymerizationable mimic mussel protein structure monomer, dopamine methacrylamide (DMA), was synthesized. The photopolymerization
of DMA was analysed by series real time near infrared spectroscopy (SRTIR). Dopamine methacrylamide/poly (ethylene oxide)
(DMA/PEO) nanofibers were successfully prepared by electrospinning of aqueous DMA/PEO solution. Biocompatible nanofibrous
membrane with good adhesion was produced by photocuring from the DMA/PEO nanofibers. The surface characterization and structure
of the composite nanofibrous membrane were characterized by a scanning electron microscopy (SEM) and contact angle measurements.
For identifying the potential crystalline of curing, a XRD method was used through comparing diffraction data. In the cell
adhesion test we utilized the mouse fibroblast (L929) to exam the various use of the nanofibrous membrane as scaffolding materials
for skin regeneration. 相似文献
998.
By applying a method due to Saint Raymond, we prove the existence of infinitely many weak solutions for a quasilinear elliptic
partial differential equation, involving the p-Laplacian operator, coupled with a nonlinear boundary condition. Our main assumption is a suitable oscillatory behaviour
of the nonlinearity either at infinity or at zero. 相似文献
999.
Unbounded stochastic control problems may lead to Hamilton-Jacobi-Bellman equations whose Hamiltonians are not always defined,
especially when the diffusion term is unbounded with respect to the control. We obtain existence and uniqueness of viscosity
solutions growing at most like o(1+|x|
p
) at infinity for such HJB equations and more generally for degenerate parabolic equations with a superlinear convex gradient
nonlinearity. If the corresponding control problem has a bounded diffusion with respect to the control, then our results apply
to a larger class of solutions, namely those growing like O(1+|x|
p
) at infinity. This latter case encompasses some equations related to backward stochastic differential equations. 相似文献
1000.
Mohammad El SmailyFrançois Hamel Rui Huang 《Nonlinear Analysis: Theory, Methods & Applications》2011,74(17):6469-6486
This paper is devoted to the study of traveling fronts of reaction-diffusion equations with periodic advection in the whole plane R2. We are interested in curved fronts satisfying some “conical” conditions at infinity. We prove that there is a minimal speed c∗ such that curved fronts with speed c exist if and only if c≥c∗. Moreover, we show that such curved fronts are decreasing in the direction of propagation, that is, they are increasing in time. We also give some results about the asymptotic behaviors of the speed with respect to the advection, diffusion and reaction coefficients. 相似文献