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Namba K, Mutai H, Kaneko H, Hashimoto S, Matsunaga T. In silico modeling of the pore region of a KCNQ4 missense mutant from a patient with hearing loss. BMC Res Notes 2012; 5:145. [PMID: 22420747 PMCID: PMC3374714 DOI: 10.1186/1756-0500-5-145] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Accepted: 03/15/2012] [Indexed: 11/16/2022] Open
Abstract
Background Mutation of the voltage-gated potassium channel KCNQ4 causes DFNA2-type nonsyndromic autosomal dominant sensorineural hearing loss. KCNQ4 is expressed predominantly in the auditory sensory outer hair cells, which are critical for sound amplification. Results We sequenced KCNQ4 from Japanese patients with sensorineural hearing loss, and identified a novel missense mutation encoding a Tyr270His located at the N-terminus of the highly conserved pore helix sequence. As this patient was not accessible to us and information about them was limited, we used molecular modeling to investigate whether this novel mutation is hypothetically pathogenic. A careful examination of an in silico structural model of the KCNQ4 pore region revealed that the Tyr270His mutation caused an alteration in the electrostatic surface potential of the pore helix. Conclusion We propose two possible means by which the Tyr270His mutation causes hearing loss: a positively charged His270 side chain might enhance the helix dipole moment of the pore helix, thereby destabilizing the helix and/or the pore region, or it might disturb transport of K+ through the channel by electrostatic repulsion.
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Affiliation(s)
- Kazunori Namba
- Laboratory of Auditory Disorders, National Institute of Sensory Organs, National Tokyo Medical Center, Tokyo, Japan
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Shi X, Meng X, Sun L, Liu J, Zheng J, Gai H, Yang R, Yeung ES. Observing photophysical properties of quantum dots in air at the single molecule level: advantages in microarray applications. LAB ON A CHIP 2010; 10:2844-2847. [PMID: 20714508 DOI: 10.1039/c005258b] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Quantum dots (QDs) are promising fluorescent tags for microarrays. Because most microarrays are analyzed under dry conditions, it is necessary to examine the photo properties of QDs in air. We demonstrate that the photophysical characteristics of individual quantum dots are different at the liquid/solid interface compared with QDs at the air/solid interface by observing them through a wide-field fluorescence microscope. QDs in air show higher photo-stability, higher fluorescence signal, slower spectral blue shift rate, less blinking and shorter bulk fluorescence lifetime than those in solution. These beneficial properties indicate QDs are good alternative fluorescent probes for microarrays.
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Affiliation(s)
- Xingbo Shi
- Biological College, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, Hunan 410082, China
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Stauber J, El Ayed M, Wisztorski M, Day R, Fournier I, Salzet M. Polymerase Chain Reaction and Immunoassay−Matrix Assisted Laser Desorption Mass Spectrometry Using Tag-Mass Technology: New Tools to Break Down Quantification Limits and Multiplexes. Anal Chem 2009; 81:9512-21. [DOI: 10.1021/ac901416s] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- J. Stauber
- University de Lille1, CNRS, MALDI Imaging Team, Laboratoire de Neuroimmunologie des Annélides, Villeneuve d’Ascq F-59655, France, and Université de Sherbrooke, Département de Pharmacologie, Faculté de médecine, Sherbrooke, Québec, J1H 5N4, Canada
| | - M. El Ayed
- University de Lille1, CNRS, MALDI Imaging Team, Laboratoire de Neuroimmunologie des Annélides, Villeneuve d’Ascq F-59655, France, and Université de Sherbrooke, Département de Pharmacologie, Faculté de médecine, Sherbrooke, Québec, J1H 5N4, Canada
| | - M. Wisztorski
- University de Lille1, CNRS, MALDI Imaging Team, Laboratoire de Neuroimmunologie des Annélides, Villeneuve d’Ascq F-59655, France, and Université de Sherbrooke, Département de Pharmacologie, Faculté de médecine, Sherbrooke, Québec, J1H 5N4, Canada
| | - R. Day
- University de Lille1, CNRS, MALDI Imaging Team, Laboratoire de Neuroimmunologie des Annélides, Villeneuve d’Ascq F-59655, France, and Université de Sherbrooke, Département de Pharmacologie, Faculté de médecine, Sherbrooke, Québec, J1H 5N4, Canada
| | - I. Fournier
- University de Lille1, CNRS, MALDI Imaging Team, Laboratoire de Neuroimmunologie des Annélides, Villeneuve d’Ascq F-59655, France, and Université de Sherbrooke, Département de Pharmacologie, Faculté de médecine, Sherbrooke, Québec, J1H 5N4, Canada
| | - M. Salzet
- University de Lille1, CNRS, MALDI Imaging Team, Laboratoire de Neuroimmunologie des Annélides, Villeneuve d’Ascq F-59655, France, and Université de Sherbrooke, Département de Pharmacologie, Faculté de médecine, Sherbrooke, Québec, J1H 5N4, Canada
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