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Study of the interaction of unaggregated and aggregated amyloid β protein (10-21) with outward potassium channel

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Science China Chemistry 2007年第5期50卷 683-691页

作者： ZHANG ChaoFeng FAN Li YANG Pin Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education Institute of Molecular Science Shanxi University Taiyuan 030006 China Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education Institute of Molecular Science Shanxi University Taiyuan 030006 China Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education Institute of Molecular Science Shanxi University Taiyuan 030006 China

Metal ion-induced aggregation of A beta into insoluble plaques is a centralfactor in Alzheimer's ***^(2+) is the only physiologically available transition metal ionresponsible for aggregating A beta at pH *** make it clear that the neurotoxicity ofZn^(2+)-induced aggregation of A beta on neurons is the key to understand A beta mechanism of *** this paper,we choose A/?(10-21) as the model fragment to research hippocampal CA1pyramidal *** the first time,we adopt the combination of spectral analysis with patch-clamptechnique for the preliminary study of the mutual relations of Zn^(2+),A beta and ion channel fromthe cell *** following expounds upon the effects and mode of action of two forms (unaggregatedand aggregated) of A beta(10-21) on hippocampus outward potassium channel three processes(activation,inactivation and reactivation).It also shows the molecular mechanics of AD from thechannel *** results are significant for the further study of A beta nosogenesis and thedevelopment of new types of target drugs for the treatment of AD.

关键词： potassium channel amyloid beta protein (10-21) Zn^(2+) alzheimer's disease

Permeation mechanism of a two-state potassium channel

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Frontiers in Biology 2007年第1期2卷 108-113页

作者： WANG Xiangqun ZHAO Tongjun SONG Yang ZHAN Yong School of Science Hebei University of TechnologyTianjin 300130China

A two-state hopping model was proposed to study the permeation of ion *** Nernst equation in equilibrium and the Michaelis-Menten relation in steady state were derived from the two-state kinetic *** currentvoltage relationship obtained in the symmetrical solutions case was linear when the applied potential was less than 100 mV,which met Ohm’s *** conductance-concentration relationship exhibited the saturation ***,the characteristic time reaching the steady state of the KcsA channel was also discussed.

关键词： potassium channel selectivity filter master equation

NONLINEAR　PROPERTY　MEMBRANE　RECTIFIER　potassium　channel　AND　INHIBITORY　EFFECTS　OF　OXYGEN　FREE　RADICAL

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Chinese Medical Sciences Journal 1996年第3期11卷 174-176页

作者：鲍光宏于德洁刘宇刘东梅 Institute of Basic Medical Sciences CAMS Beijing.

There are at least eight kinds of different potassium channels on cardiac cell *** paper presents a nonlinear property membrane outward current going rectifying potassium channel and the inhibitory effects of oxygen free radical on this *** current-voltage relation of this nonlinear-membrane can be defined by an equation I= 8a3/(0.01v2+ 4a2)2 and the maximum conductance of this channel is-75.3 PS.

关键词： potassium channel rectifier free radical

potassium channel blockers as an effective treatment to restore impulse conduction in injured axons

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Neuroscience Bulletin 2011年第1期27卷 36-44页

作者：史日异孙文婧普渡大学韦尔登生物医学工程学院兽医学院基础医学系

Most axons in the vertebral central nervous system are myelinated by *** protects and insulates neuronal processes,enabling the fast,saltatory conduction unique to myelinated *** disruption resulting from trauma and biochemical reaction is a common pathological event in spinal cord injury and chronic neurodegenerative *** damage-induced axonal conduction block is considered to be a significant contributor to the devastating neurological deficits resulting from trauma and *** channels are believed to play an important role in axonal conduction failure in spinal cord injury and multiple *** damage has been shown to unmask potassium channels,creating aberrant potassium currents that inhibit *** channel blockade reduces this ionic leakage and improves *** present review was mainly focused on the development of this technique of restoring axonal conduction and neurological function of demyelinated *** drug 4-aminopyridine has recently shown clinical success in treating multiple sclerosis *** translational research has also identified several novel potassium channel blockers that may prove effective in restoring axonal conduction.

关键词： axon conduction potassium channel injury demyelination 4-aminopyridine

Bisoprolol reverses down-regulation of potassium channel proteins in ventricular tissues of rabbits with heart failure

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The Journal of Biomedical Research 2011年第4期25卷 274-279页

作者： Xi Li Tingzhong Wang Ke Han Xiaozhen Zhuo Qun Lu Aiqun Ma Department of Cardiovascular Medicine the First Affiliated Hospital of Medical School Xi＇an Jiaotong University Xi ＇an Shaanxi 710061 China Key Laboratory of Molecular Cardiology of Shaanxi Province Xi ＇an Shaanxi 710061 China Key Laboratory of Enwronment and Genes Related to Diseases Xi＇an Jiaotong University Xi＇an Shaanxi 710061 China Department of Cardiovascular Medicine the Second Affiliated Hospital of Medical School Ningxia Medical University Yinehuan Ningxia Hui Autonomous Region 750001 China

Remodeling of ion channels is an important mechanism of arrhythmia induced by heart failure （HF）. We investigated the expression of potassium channel encoding genes in the ventricles of rabbit established by volumeoverload operation followed with pressure-overload. The reversible effect of these changes with bisoprolol was also evaluated. The HF group exhibited left ventricular enlargement, systolic dysfunction, prolongation of corrected QT interval （QTc）, and increased plasma brain natriuretic peptide levels in the HF rabbits. Several potassium channel subunit encoding genes were consistently down-regulated in the HF rabbits. After bisoprolol treatment, heart function was improved significantly and QTc was shortened. Additionally, the mRNA expression of potassium channel subunit genes could be partially reversed. The down-regulated expression of potassium channel subunits Kv4.3, Kv1.4, KvLQT1, minK and Kir 2.1 may contribute to the prolongation of action potential duration in the heart of rabbits induced by volume combined with pressure overload HF. Bisoprolol could partially reverse these down-regulations and improve heart function.

关键词： heart failure potassium channel down-regulation animal models

potassium channel of oligodendrocyte precursor cells during perinatal hypoxia-ischemia

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Potassium channel of oligodendrocyte precursor cells during ...

Screening of potassium channel mutations in patients with atrial fibrillation

中国神经科学学会第九届全国学术会议暨第五次会员代表大会

作者： Peng-Hui CHEN,Wen-Qin CAI~* Department of Neurobiology,Chongqing Key Laboratory of Neurobiology,Third Military Medical University, Chongqing 400038,China

＜正＞Objective Oligodendrocyte precursor cells（OPC）are particularly susceptible to perinatal hypoxia-ischemia resulting in decreased myelination and infant cerebral *** precise mechanism remains *** recordings from these cells have revealed that they possess unique potassium channel properties,which are distinct from the traditional class of glial cell and *** study is to explore whether rectified potassium channel of OPC is involved in hypoxia ischemic brain *** Whole cell voltage dependent ion channels were recorded by patch clamp technology in acute brain slices of postnatal 7 days rats after hypoxia-ischemia 2 *** recorded cell,which was injected intracellular Lucifer yellow,was identified with the marker NG2 by fluorescent ***（1）Sodium to potassium conductance ratio was decreased,owing to the increase of inward sodium current amplitude.（2）Outward rectified potassium channel exhibited rectify fall off.（3）There was no significant difference in variable rectified potassium channel and inward rectified potassium channel.（4）Tail current and activation voltage were all raised,which reduced activation and inactivation of potassium *** Outward rectified potassium channel and tail current of potassium channel play more important role in OPC susceptible to hypoxia ischemia.

关键词： oligodendrocyte precursor cell(OPC) patch clamp hypoxia-ischemia potassium channel rectify

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Screening of potassium channel mutations in patients with at...

Molecular basis for toxin resistance of Mesobuthus martensii voltage-gated potassium channel:insights into potassium channel evolution

中国生理学会第24届全国会员代表大会暨生理学学术大会

作者： Tao Li Lu-Ping Zhou Gui-Lan Chen Li Huang Xiao-Rong Zeng Bo Zeng 泸州医学院忠山校区心研所

Aim:To identify gene mutations of potassium channels that contributed to the pathogenesis of atrial ***:Genomic DNA was extracted from the peripheral blood of 124 patients with atrial *** coding regions of genes including KCNE1（min K）,KCNE1L（KCNE5）,KCNE2（Mi RP1）,KCNE4（Mi RP3）,KCNJ2（Kir2.1）and KCNJ4（Kir2.3）were amplified from the genomic DNA and sequenced with corresponding *** obtained sequences were aligned with reference sequences from Gen *** found in the alignments were confirmed by manual check on the original sequencing ***:Mutations leading to changes of amino acids and corresponding mutation rates were found:KCNE1,S37R（0.8%）,S38G（92.7%）,D85N（0.8%）;KCNE1L,Y81H（0.16%）;KCNE2,none;KCNE4,M109V（0.8%）,D196E（91.1%）;KCNJ2,V93I（0.8%）;KCNJ4,***:Genetic mutations on potassium channels are important pathogenetic factors of atrial *** the six genes screened KCNE1 and KCNE4 showed highest mutation *** electrophysiological functionality of these mutants needs to be examined in the future to understand their impacts to the cardiac action potential.

关键词： potassium channel atrial fibrillation mutation

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Molecular basis for toxin resistance of Mesobuthus martensii...

potassium channelS ON CARDIOMYOCYTES OF SELENIUM IODINE DEFICIENCY RATS AND IODINE DEFICIENCY RATS

第12届生物毒素研究及医药应用学术大会

作者： Chuangeng Zhang Zili Xie Xinxin Li Jing Chen Yange Lang Wenxin Li Zhijian Cao Yingliang Wu State Key Laboratory of Virology College of Life SciencesWuhan University Center for BioDrug Research Wuhan University

It remains unclear why scorpions are immune to own venoms containing various neurotoxins specific for the mammalian or insect ion *** functional characterization of scorpion ion channels can uncovers such resistance *** on the functional potassium channel MmKv1 from Mesobuthus martensii genome,the channel kinetic experiments showed MmKv1 was a classical voltage-gated potassium channel with a voltage-dependent fast activation and then a voltage-dependent slow inactivation *** comparison with both venom and toxin sensitive human Kv1.3 channel,the MmKv1 channel showed the remarkable resistance to both scorpion venom and *** chimeric channel in which the extracellular pore region of MmKv1 channel was replaced by equivalent region from Kv1.3 channel revealed that both the channel turret and filter region domains were critical for the toxin *** on the chimeric channel,the mutagenesis experiments further indicated that two basic residues Arg399 and Lys403 in the MmKv1 channel turret and Arg425 in the MmKv1 channel filter region significantly affected toxin *** these three basic residues of MmKv1 channel were simultaneously substituted by the corresponding polar or weak basic residues from Kv1.3 channel,the resulted MmKv1-R399T/K403S/R425 H channel exhibited similar sensitivity towards both scorpion venom and toxin to that of Kv1.3 channel,which revealed the determinative role of basic residues Arg399,Lys403 and Arg425 in the toxin resistance of MmKv1 *** addition,sequence alignment showed these three basic residues are conserved in the Shaker-like channels of invertebrate venomous animals,which further suggested their convergent evolution to resist their own venoms.

关键词： scorpion toxin resistance potassium channel molecular mechanism convergent evolution

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Chinese Medical Sciences Journal 1997年第1期12卷 57-59页

作者：鲍光宏吴晖云于德洁刘东梅王洪全 Institute of Basic Medical Sciences CAMS & PUMC Beijing 100730.

Uging diet control method to feed the weaning male Wistar rats with selenium and iodine deficiency Keshan endemic area food for 8 weeks to set up animal model. Singal channel recortling in cell attached model was used to measure cardiac cell membrane potassium channel conductances. which coincide with the cardiac cell membrane potassium channel conductances in normal Wistar *** potassium channel conductance on selenlum and lodine cleficiency rat cardiac cell membrane is showing current-voltage increasing lineally in the range of clamping volatge 0±30 mV with channel conductance of 43.4 pS. The channel current does not increase depending on the clamping voltage that is showing the rectifying characteristic and the channel current amplitude can be augmented by added KIOa 5 mmol/L in bath solution. A kind of inward rectiyfing potassium channel activity was recorded, but this channel activity disappeared affer lasting 6～ 10 minutes only. Then an inward rectifying potassium channel with the conductance of 11. 2 PS was activated by KIOa 5 mmol/L, introduced to bath solution. Both conductances are less than that of normal Wistar rats.

关键词： cardiomyocytes selenium iodine potassium channel