Yu Huang

Bio: Yu Huang is an academic researcher from Chinese Academy of Sciences. The author has contributed to research in topics: Medicine & Materials science. The author has an hindex of 136, co-authored 1492 publications receiving 89209 citations. Previous affiliations of Yu Huang include The Chinese University of Hong Kong & Samsung.

Conserved cysteine residues in the shaker k+ channel are not linked by a disulfide bond

Abstract: Many voltage-activated K+ channels contain two conserved cysteine residues in putative transmembrane segments S2 and S6. It has been proposed that these cysteines form an intrasubunit disulfide bond [Guy, H.R., & Conti, F. (1990) Trends Neurosci. 13, 201-206]. This proposal was tested using site-directed mutagenesis followed by electrophysiological and biochemical analysis of the Shaker B K+ channel. Each Shaker B subunit contains seven cysteine residues, including the conserved residues C286 and C462 and a less conserved cysteine, C245. Each cysteine in the Shaker B protein can be mutated individually without eliminating functional activity, indicating that the protein does not contain a disulfide bond that is essential for protein folding or the assembly of active channels. To determine whether there is a nonessential disulfide bond, Shaker B protein was subjected to limited proteolysis. Fragments were analyzed by electrophoresis under reducing and nonreducing conditions followed by immunoblotting. The results indicate that the two conserved residues C286 and C462 do not form a disulfide bond with each other or with C245. In addition, the subunits are not linked by disulfide bonds. In HEK293T cells, Shaker B protein is first made as an incompletely glycosylated precursor that is converted to the fully glycosylated mature protein. Glycosylation occurs at two positions in the S1-S2 loop.

Mechanisms of Elemental Mercury Transformation on α-Fe2O3(001) Surface from Experimental and Theoretical Study: Influences of HCl, O2, and SO2

Abstract: The reaction mechanisms of a mixture gas of HCl, O2, and SO2 in Hg0 adsorption on α-Fe2O3(001) surface are clarified by a group of adsorption experiments and theoretical calculations based on the density functional theory. The role of O2 in removing Hg0 is greatly influenced by the reaction temperature, meanwhile, the O atom coverage could affect the adsorption performance of Hg0. The dissociated O2 competes with the active sites of Cl species on Fe surface at low temperature, however, at medium temperature HCl and O2 could simultaneously facilitate the Hg0 transformation. Combined with the theoretical calculations, the role of SO2 and the probable pathways in removing Hg0 are discussed. Lower concentration of SO2 as well as HCl could dissociate on α-Fe2O3(001) surface, and the intermediates combine with gaseous Hg0, forming mercury–sulfur, mercury–chlorine compounds, and so forth. In addition, the different concentrations of SO2 are also discussed, and the corresponding X-ray photoelectron spectroscopy a...

Nitric oxide and protein kinase G act on TRPC1 to inhibit 11,12-EET-induced vascular relaxation

Abstract: Aims Vascular endothelial cells synthesize and release vasodilators such as nitric oxide (NO) and epoxyeicosatrienoic acids (EETs). NO is known to inhibit EET-induced smooth muscle hyperpolarization and relaxation. This study investigates the underlying mechanism of this inhibition. Methods and results Through measurements of membrane potential and arterial tension, we show that 11,12-EET induced membrane hyperpolarization and vascular relaxation in endothelium-denuded porcine coronary arteries. These responses were suppressed by S -nitroso- N -acetylpenicillamine (SNAP) and 8-Br-cGMP, an NO donor and a membrane-permeant analogue of cGMP, respectively. The inhibitory actions of SNAP and 8-Br-cGMP on 11,12-EET-induced membrane hyperpolarization and vascular relaxation were reversed by hydroxocobalamin, an NO scavenger; ODQ, a guanylyl cyclase inhibitor; and KT5823, a protein kinase G (PKG) inhibitor. The inhibitory actions of SNAP and 8-bromo cyclic GMP (8-Br-cGMP) on the EET responses were also abrogated by shielding TRPC1-PKG phosphorylation sites with an excessive supply of exogenous PKG substrates, TAT-TRPC1S172 and TAT-TRPC1T313. Furthermore, a phosphorylation assay demonstrated that PKG could directly phosphorylate TRPC1 at Ser172 and Thr313. In addition, 11,12-EET failed to induce membrane hyperpolarization and vascular relaxation when TRPV4, TRPC1, or KCa1.1 was selectively inhibited. Co-immunoprecipitation studies demonstrated that TRPV4, TRPC1, and KCa1.1 physically associated with each other in smooth muscle cells. Conclusion Our findings demonstrate a novel role of the NO-cGMP-PKG pathway in the inhibition of 11,12-EET-induced smooth muscle hyperpolarization and relaxation via PKG-mediated phosphorylation of TRPC1.

Mixed-solvent liquid exfoliated MoS2 NPs as peroxidase mimetics for colorimetric detection of H2O2 and glucose

Abstract: Ultra-small molybdenum disulfide nanoparticles (MoS2 NPs) were prepared by a facile liquid exfoliation method with ethanol/water as the solvent The produced MoS2 NPs were of high purity due to the easily removable ethanol/water solution The prepared MoS2 NPs exhibited an intrinsic peroxidase-like activity in analogy to that of horseradish peroxidase (HRP) A custom-made spectrometer was employed to investigate the peroxidase-like activity of MoS2 NPs in the presence of H2O2 and glucose The change in absorption detected from MoS2 NPs is proportional to the amount of target The calibration curve of H2O2 and glucose shows a good relationship between the concentration of target and the change in the absorption of MoS2 NPs The limit of detection of H2O2 and glucose achieved by this method could approach 125 μM and 7 μM respectively This method has been applied for the detection of glucose in serum from humans Therefore, these produced MoS2 NPs offer an alternative high-efficiency and economic way to detect diabetes

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Fast parallel algorithms for short-range molecular dynamics

Abstract: Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。