A novel member of extremely halophilic archaea, strain AJ2, was isolated from Ayakekum Lake located in Altun Mountain National Nature Reserve of Xinjiang Uygur Autonomous Region in China. The strain A J2 requires at l...A novel member of extremely halophilic archaea, strain AJ2, was isolated from Ayakekum Lake located in Altun Mountain National Nature Reserve of Xinjiang Uygur Autonomous Region in China. The strain A J2 requires at least 10% (w/v)NaCl and grows 10% to 30% (optimum at 20%). Phylogenetic analysis based on 16S rDNA sequence comparison revealed that strain A J2 clustered to three Natrinema species with less than 97.7% sequence similarities, suggesting A J2 is a novel member of Natrinema. A bacteriorhodopsin-encoding (bop) gene was subsequently detected in the A J2 genome using the polymerase chain reaction technique. The cloning and sequencing of a 401 base pairs fragment indicated the deduced amino acid sequence of bop from A J2 is different from that reported for bacteriorhodopsins. This is the first reported detection of a bop gene in Natrinema.展开更多
The Cu(Ⅱ) separation behaviors with polymer inclusion membranes(PIMs) are explored by modifying 2-aminomethylpyridine derivatives with hydrophobic alkyl chains, including 2-[N-(tert-butyloxycarbonylmethyl)-2-picolyam...The Cu(Ⅱ) separation behaviors with polymer inclusion membranes(PIMs) are explored by modifying 2-aminomethylpyridine derivatives with hydrophobic alkyl chains, including 2-[N-(tert-butyloxycarbonylmethyl)-2-picolyamino]acetate(AMB), N,N-dioctyl-2-aminomethylpyridine(AMD), tert-butyl 2-(N-octyl-2-picolyamino) acetate(AMC), and N,N-didecyl-2-aminomethylpyridine(AME). The transport flux and selectivity of Cu(Ⅱ) are determined by optimizing composition and structure of carriers and plasticizers. The results show that the hydrophobic modification of 2-aminomethylpyridine derivatives can boost the selective transport of copper ions in PIMs and membrane stability. In the optimum composition of 30 wt.% PVC, 30 wt.% AME, and 40 wt.% NPOE, the initial flux of Cu(Ⅱ) is 5.8×10^(−6) mol·m^(−2)·s^(−1). The FT-IR and XPS spectra identify that the alkyl amine functional groups of AME involve in the transport of copper chloride species. The SAXS analysis demonstrates that the generated micro-channels in PIMs induced by the hydrophobic modification of 2-aminomethylpyridine derivatives can contribute to the enhanced Cu(Ⅱ) flux.展开更多
This paper describes theoretical steps to develop an optical nanobiosensor using bacteriorhodopsin （BR） as the biomembrane and Single-Walled Carbon NanoTube （SWCNT） as the scaffold. Bacteriorhodopsin is a retinal ...This paper describes theoretical steps to develop an optical nanobiosensor using bacteriorhodopsin （BR） as the biomembrane and Single-Walled Carbon NanoTube （SWCNT） as the scaffold. Bacteriorhodopsin is a retinal protein used by archaea that come under the family of halobacteria. This retinal protein acts as a proton pump and resulting proton gradient is used to change the voltage that pass across the drain and source. The biosensor contains nano ISFET where the channel is made of a carbon nanotube for the conduction of current. The gate is replaced by bacteriorhodopsin biomembrane. Bacteriorhodopsin can be used as a molecular-level ultra fast bi-stable red / green photo switch for making 3D optical molecular memories that reliably store data with 10,000 molecules/bit. The molecules switch in femtoseconds. Biomembrane will sense 510 nm and 650 nm wavelength of light and the sensing voltage can be used to convert the data into digital signals. This molecular level memory device can be used for ‘Read-Write＇ operations. The sensor performance will also be ultra fast since it uses photons for the data storage, which are much faster than electrons used in normal memory devices, and the 3D storage capacity is much higher maximum of 10^13/cm^2.展开更多
The spatial distribution of extracellular polymeric substances （EPS） in a pilot-scale membrane bioreactor （MBR） was studied. The sampling points on top of and inside the membrane module were measured and analyzed ...The spatial distribution of extracellular polymeric substances （EPS） in a pilot-scale membrane bioreactor （MBR） was studied. The sampling points on top of and inside the membrane module were measured and analyzed by the experimental variant function. The content of EPS was spatially interpolated by ordinary Kriging method, and il- lustrated with SURFER software. A case study was carried out in an MBR with membrane aperture of 0.4 ~tm and handling capacity of 120 ma/d in Jizhuangzi sewage treatment plant, Tianjin. From the visualization of EPS distribu- tion, it is seen that on the horizontal plane, the content of EPS was the lowest at the center; and on the vertical plane, the content of EPS decreased with the increase of depth. The shearing force caused by aeration of perforated pipe and the influent mode are the main influencing factors for this distribution.展开更多
Objective ： To detect 3-dimensional images of anti-N-methyl-D-aspartate receptor Nrl （ NMDAr1 ） polycolonal lgG affixed on mica in physiological environment. Methods： The images and data were obtained from a cont...Objective ： To detect 3-dimensional images of anti-N-methyl-D-aspartate receptor Nrl （ NMDAr1 ） polycolonal lgG affixed on mica in physiological environment. Methods： The images and data were obtained from a contact mode and commercial Si3N4 probed tip by using atomic force microscope （ AFM ）. Results： The anti-NMDArl polycolonal IgG has a characteristic structure described as an ellipse spherical shape of 136.4 A × 62.8 A × 26.1 A. On the section of theellipse edge there were two peaks about 13nm in width. Conclusions ： Using AFM to investigate biomacromolecule can make us deeply understand the structure of IgG, which will instruct us to detect the membrane receptor protein as a labelling agent.展开更多
Motivated by several long-lasting mechanistic questions for biomolecular proton pumps,we have engaged in developing hybrid quantum mechanical/molecular mechanical(QM/MM) methods that allow an efficient and reliable de...Motivated by several long-lasting mechanistic questions for biomolecular proton pumps,we have engaged in developing hybrid quantum mechanical/molecular mechanical(QM/MM) methods that allow an efficient and reliable description of long-range proton transport in transmembrane proteins.In this review,we briefly discuss several relevant issues:the need to develop a "multi-scale" generalized solvent boundary potential(GSBP) for the analysis of chemical events in large trans-membrane proteins,approaches to validate such a protocol,and the importance of improving the flexibility of QM/MM Hamiltonian.Several recent studies of model and realistic protein systems are also discussed to help put the discussions into context.Collectively,these studies suggest that the QM/MM-GSBP framework based on an approximate density functional theory(SCC-DFTB) as QM holds the promise to strike the proper balance between computational efficiency,accuracy and generality.With additional improvements in the methodology and recent developments by others,especially powerful sampling techniques,this "multi-scale" framework will be able to help unlock the secrets of proton pumps and other biomolecular machines.展开更多
文摘A novel member of extremely halophilic archaea, strain AJ2, was isolated from Ayakekum Lake located in Altun Mountain National Nature Reserve of Xinjiang Uygur Autonomous Region in China. The strain A J2 requires at least 10% (w/v)NaCl and grows 10% to 30% (optimum at 20%). Phylogenetic analysis based on 16S rDNA sequence comparison revealed that strain A J2 clustered to three Natrinema species with less than 97.7% sequence similarities, suggesting A J2 is a novel member of Natrinema. A bacteriorhodopsin-encoding (bop) gene was subsequently detected in the A J2 genome using the polymerase chain reaction technique. The cloning and sequencing of a 401 base pairs fragment indicated the deduced amino acid sequence of bop from A J2 is different from that reported for bacteriorhodopsins. This is the first reported detection of a bop gene in Natrinema.
基金financial supports from the National Key R&D Program of China(No.2019YFC1907801)National Natural Science Foundation of China(No.52174286)+1 种基金Hunan Provincial Science and Technology Plan Project,China(No.2019JJ30031)InnovationDriven of Central South University,China(No.2020CX007)。
文摘The Cu(Ⅱ) separation behaviors with polymer inclusion membranes(PIMs) are explored by modifying 2-aminomethylpyridine derivatives with hydrophobic alkyl chains, including 2-[N-(tert-butyloxycarbonylmethyl)-2-picolyamino]acetate(AMB), N,N-dioctyl-2-aminomethylpyridine(AMD), tert-butyl 2-(N-octyl-2-picolyamino) acetate(AMC), and N,N-didecyl-2-aminomethylpyridine(AME). The transport flux and selectivity of Cu(Ⅱ) are determined by optimizing composition and structure of carriers and plasticizers. The results show that the hydrophobic modification of 2-aminomethylpyridine derivatives can boost the selective transport of copper ions in PIMs and membrane stability. In the optimum composition of 30 wt.% PVC, 30 wt.% AME, and 40 wt.% NPOE, the initial flux of Cu(Ⅱ) is 5.8×10^(−6) mol·m^(−2)·s^(−1). The FT-IR and XPS spectra identify that the alkyl amine functional groups of AME involve in the transport of copper chloride species. The SAXS analysis demonstrates that the generated micro-channels in PIMs induced by the hydrophobic modification of 2-aminomethylpyridine derivatives can contribute to the enhanced Cu(Ⅱ) flux.
文摘This paper describes theoretical steps to develop an optical nanobiosensor using bacteriorhodopsin （BR） as the biomembrane and Single-Walled Carbon NanoTube （SWCNT） as the scaffold. Bacteriorhodopsin is a retinal protein used by archaea that come under the family of halobacteria. This retinal protein acts as a proton pump and resulting proton gradient is used to change the voltage that pass across the drain and source. The biosensor contains nano ISFET where the channel is made of a carbon nanotube for the conduction of current. The gate is replaced by bacteriorhodopsin biomembrane. Bacteriorhodopsin can be used as a molecular-level ultra fast bi-stable red / green photo switch for making 3D optical molecular memories that reliably store data with 10,000 molecules/bit. The molecules switch in femtoseconds. Biomembrane will sense 510 nm and 650 nm wavelength of light and the sensing voltage can be used to convert the data into digital signals. This molecular level memory device can be used for ‘Read-Write＇ operations. The sensor performance will also be ultra fast since it uses photons for the data storage, which are much faster than electrons used in normal memory devices, and the 3D storage capacity is much higher maximum of 10^13/cm^2.
基金Supported by Special Fund Project for Technology Innovation of Tianjin (No.06FZZDSH00900)
文摘The spatial distribution of extracellular polymeric substances （EPS） in a pilot-scale membrane bioreactor （MBR） was studied. The sampling points on top of and inside the membrane module were measured and analyzed by the experimental variant function. The content of EPS was spatially interpolated by ordinary Kriging method, and il- lustrated with SURFER software. A case study was carried out in an MBR with membrane aperture of 0.4 ~tm and handling capacity of 120 ma/d in Jizhuangzi sewage treatment plant, Tianjin. From the visualization of EPS distribu- tion, it is seen that on the horizontal plane, the content of EPS was the lowest at the center; and on the vertical plane, the content of EPS decreased with the increase of depth. The shearing force caused by aeration of perforated pipe and the influent mode are the main influencing factors for this distribution.
文摘Objective ： To detect 3-dimensional images of anti-N-methyl-D-aspartate receptor Nrl （ NMDAr1 ） polycolonal lgG affixed on mica in physiological environment. Methods： The images and data were obtained from a contact mode and commercial Si3N4 probed tip by using atomic force microscope （ AFM ）. Results： The anti-NMDArl polycolonal IgG has a characteristic structure described as an ellipse spherical shape of 136.4 A × 62.8 A × 26.1 A. On the section of theellipse edge there were two peaks about 13nm in width. Conclusions ： Using AFM to investigate biomacromolecule can make us deeply understand the structure of IgG, which will instruct us to detect the membrane receptor protein as a labelling agent.
基金supported in part by NIH grant R01-GM084028NSF grant CHE-0957285+1 种基金U.S.Department of Energy Genomics:GTL and Sci-DAC Programs (DEFG02-04ER25627)supported in part by the National Science Foundation through a major instrumentation grant (CHE-0840494)
文摘Motivated by several long-lasting mechanistic questions for biomolecular proton pumps,we have engaged in developing hybrid quantum mechanical/molecular mechanical(QM/MM) methods that allow an efficient and reliable description of long-range proton transport in transmembrane proteins.In this review,we briefly discuss several relevant issues:the need to develop a "multi-scale" generalized solvent boundary potential(GSBP) for the analysis of chemical events in large trans-membrane proteins,approaches to validate such a protocol,and the importance of improving the flexibility of QM/MM Hamiltonian.Several recent studies of model and realistic protein systems are also discussed to help put the discussions into context.Collectively,these studies suggest that the QM/MM-GSBP framework based on an approximate density functional theory(SCC-DFTB) as QM holds the promise to strike the proper balance between computational efficiency,accuracy and generality.With additional improvements in the methodology and recent developments by others,especially powerful sampling techniques,this "multi-scale" framework will be able to help unlock the secrets of proton pumps and other biomolecular machines.
