检索结果-南通市图书馆

维普期刊数据库

Two Potent α3/5 Conotoxins from Piscivorous Conus achatinus

在线全文

学校读者我要写书评

暂无评论

Acta Biochimica et Biophysica Sinica 2007年第6期39卷 438-444页

作者： Geoffrey CHEW Edward HAWROT Department of Molecular Pharmacology Physiology and Biotechnology Brown University Providence Rhode Island 02903 USA

Every cone snail produces a mixture of different conotoxins and secretes them to immobilize their prey and predators. α3/5 Conotoxins, isolated from fish-hunting cone snails, target muscle nicotinic acetylcholine receptors. The structure and function of α3/5 conotoxin from the piscivorous Conus achatinus have not been studied. We synthesized two pentadecamer peptides, Ac 1.1 a and Ac 1.1 b, with appropriate disulfide bonding, based on cDNA sequences of α3/5 conotoxins from C. achatinus. Ac 1.1 a and Ac 1.1 b differ by only one amino acid residue. They have similar potency on blocking recombinant mouse muscle acetylcholine receptor expressed in Xenopus laevis oocytes, with IC50values of 36 nM and 26 nM, respectively. For Ac 1.1b, deletion of the first three N-terminal amino acids did not change its activity, indicating that the Nterminus is not involved in the interaction with its receptor. Furthermore, our experiments indicate that both toxins strongly prefer the α1-δ subunit interface instead of the α1-γ binding site on the mouse muscle nicotinic acetylcholine receptor. These peptides provide additional tools for the study of the structure and function of nicotinic receptor.

关键词： cone snail α3/5 conotoxin disulfide bond nicotinic acetylcholine receptor

Effects of L-arginine and N~ω-nitro-L-arginine methylester on learning and memory and α7 nAChR expression in the prefrontal cortex and hippocampus of rats

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neuroscience Bulletin 2013年第3期29卷 303-310页

作者： Xiao-Ming Wei Wei Yang Li-Xia Liu Wen-Xiu Qi Shanxi Medical University Department of Physiology Nanyang Medical College of Henan Department of Physiology Fenyang College of Shanxi Medical University

Nitric oxide （NO） is a novel type of neurotransmitter that is closely associated with synaptic plasticity, learning and memory. In the present study, we assessed the effects of Larginine and NnitroL arginine methylester （LNAME, a nitric oxide synthase inhibitor） on learning and memory. Rats were assigned to three groups receiving intracerebroventricular injections of LArg （the NO precursor）, LNAME, or 0.9% NaCI （control）, once daily for seven con secutive days. Twelve hours after the last injection, they underwent an electric shockpaired Y maze test. Twentyfour hours later, the rats＇ memory of the safe illuminated arm was tested. After that, the levels of NO and a7 nicotinic acetylcholine receptor （a7 nAChR） in the prefrontal cortex and hippocampus were assessed using an NO assay kit, and immunohistochemistry and Western blots, respectively. We found that, compared to controls, LArgtreated rats received fewer foot shocks and made fewer errors to reach the learning criterion, and made fewer errors during the memorytesting session. In contrast, LNAMEtreated rats received more foot shocks and made more errors than controls to reach the learning criterion, and made more errors during the memorytesting session. In parallel, NO content in the prefrontal cortex and hippocampus was higher in LArgtreated rats and lower inLNAME rats, compared to controls. Similarly, （]7 nAChR immunoreactivity and protein expression in the prefrontal cortex and hippocampus were higher in LArgtreated rats and lower in LNAME rats, compared to controls. These results suggest that the modulation of NO content in the brain correlates with a7 nAChR distribution and expression in the prefrontal cortex and hippocampus, as well as with learning and memory performance in the Ymaze.

关键词： nitric oxide L-arginine N-nitro-L-arginine methylester learning and memory nicotinic acetylcholine receptor cerebral cortex andhippocampus Y-maze

维普期刊数据库

Putative Mode of Action of the Monoterpenoids Linalool, Methyl Eugenol, Estragole, and Citronellal on Ligand-Gated Ion Channels

在线全文

学校读者我要写书评

暂无评论

Engineering 2020年第5期6卷 541-545页

作者： Amy SLi Akimasa Iijima Junhao Huang Qing XLi Yongli Chen College of Natural and Computational Sciences Hawaii Pacific UniversityKaneoheHI 96744USA Department of Molecular Biosciences and Bioengineering University of Hawaii at ManoaHonoluluHI 96822USA Department of Internal Medicine University of Colorado School of MedicineAuroraCO 80045USA

Essential oil has been used as sedatives,anticonvulsants,and local anesthetics in traditional medical remedies;as preservatives for food,fruit,vegetable,and grain storage;and as bio-pesticides for food ***(LL),along with a few other major components such as methyl eugenol(ME),estragole(EG),and citronellal,are the active chemicals in many essential oils such as basil *** oil and the aforementioned monoterpenoids are potent against insect ***,the molecular mechanism of action of these chemical constituents is not well *** is well-known that the c-aminobutyric acid type A receptors(GABAARs)and nicotinic acetylcholine receptor(nAChR)are primary molecular targets of the synthetic insecticides used in the market ***,the GABAAR-targeted therapeutics have been used in clinics for many decades,including barbiturates and benzodiazepines,to name just a *** this research,we studied the electrophysiological effects of LL,ME,EG,and citronellal on GABAAR and nAChR to further understand their versatility as therapeutic agents in traditional remedies and as *** results revealed that LL inhibits both GABAAR and nAChR,which may explain its insecticidal *** is a concentration-dependent,noncompetitive inhibitor on GABAAR,as the half-maximal effective concentration(EC50)values of c-aminobutyric acid(GABA)for the rat a1b3c2L GABAAR were not affected by LL:(36.2±7.9)lmol-1 and(36.1±23.8)μmol·L-1 in the absence and presence of 5 mmol·L-1 LL,*** half-maximal inhibitory concentration(IC50)of LL on GABAAR was approximately 3.2 mmol·*** that multiple monoterpenoids are found within the same essential oil,it is likely that LL has a synergistic effect with ME,which has been previously characterized as both a GABAAR agonist and a positive allosteric modulator,and with other monoterpenoids,which offers a possible explanation for the sedative and anticonvulsant effects and the insecticidal activi

关键词： Essential oil c-Aminobutyric acid type A receptor Linalool Monoterpenoid nicotinic acetylcholine receptor

维普期刊数据库

Determination of the Binding Modes ofα-Conotoxins

在线全文

学校读者我要写书评

暂无评论

Determination of the Binding Modes ofα-Conotoxins

Oxidative stress induced by beta-amyloid peptide1-42is involved in the altered composition of cellular membrane lipids and the decreased expression of nicotinic receptors in human SH-SY5Y neuroblastoma cells

第十二届海洋药物学术年会

作者： R YU N TABASSUM H CUNY DJ Adams T JIANG Key Laboratory of Marine Drugs Chinese Ministry of EducationSchool of Medicine and PharmacyOcean University of China Health Innovations Research Institute School of Medical SciencesRMIT University

Conotoxins are peptide toxins extracted from the venom ofcarnivorous marine cone snail[1,2]Members of theα-conotoxin subfamily potently block nicotinic acetylcholine receptors（nAChRs）,which are involved in signal transmission[3].nAChRs are important pharmacological targets due to their involvement in the transmission of pain stimuli and also in numerous neurological diseases and *** potency and specificity ofα-conotoxins have led to their development as drug leads[4],and also to their use in the investigation of the role of nAChRs in various physiological processes[3]This review presents published[5-7]and unpublished results from our group on study of the binding modes of theα-*** results suggest that it is efficient to combine computational modeling,and eletrophysiological data to investigate the binding modes of theα-conotoxins and based which for design novelα-conotoxin analogues for therapeutic applications

关键词： Conotoxins molecular dynamics simulation peptide nicotinic acetylcholine receptor

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Oxidative stress induced by beta-amyloid peptide1-42is invol...