Browsing by Author "Ho, Yen-Peng"

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Alpha-bungarotoxin binding to target cell in a developing visual system by carboxylated nanodiamond
(2008-05-21)
Liu, Kuang-Kai
;
Mei-Fang Chen
;
Chen, Po-Yi
;
Lee, Tony J. F.
;
Cheng, Chia-Liang
Biological molecules conjugating with nanoparticles are valuable for applications including bio-imaging, bio-detection, and bio-sensing. Nanometer-sized diamond particles have excellent electronic and chemical properties for bio-conjugation. In this study, we manipulated the carboxyl group produced on the surface of nanodiamond (carboxylated nanodiamond, cND) for conjugating with alpha-bungarotoxin (alpha-BTX), a neurotoxin derived from Bungarus multicinctus with specific blockade of alpha7-nicotinic acetylcholine receptor (alpha 7-nAChR). The electrostatic binding of cND-alpha-BTX was mediated by the negative charge of the cND and the positive charge of the alpha-BTX in physiological pH conditions. Sodium dodecyl sulfate-polyacrylamide gel analysis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI/TOF-MS) spectra displayed that alpha-BTX proteins were conjugated with cND particles via non-covalent bindings. The green fluorescence of the cND particles combining with the red fluorescence of tetramethylrhodamine-labeled a-BTX presented a yellow color at the same location, which indicated that alpha-BTX proteins were conjugated with cND particles. Xenopus laevis's oocytes expressed the human alpha 7-nAChR proteins by microinjection with alpha 7-nAChR mRNA. The cND-alpha-BTX complexes were bound to alpha 7-nAChR locating on the cell membrane of oocytes and human lung A549 cancer cells analyzed by laser scanning confocal microscopy. The choline-evoked alpha 7-nAChR-mediated inward currents of the oocytes were blocked by cND-alpha-BTX complexes in a concentration-dependent manner using two-electrode voltage-clamp recording. Furthermore, the fluorescence intensity of cND-alpha-BTX binding on A549 cells could be quantified by flow cytometry. These results indicate that cND-conjugated alpha-BTX still preserves its biological activity in blocking the function of alpha 7-nAChR, and provide a visual system showing the binding of alpha-BTX to alpha 7-nAChR.
An unopened knot protein: YbeA
(2010-04-01)
Chang, Yu-Juan
;
Yeh, Yi-Chen
;
Ho, Yen-Peng
;
Chang, Chia-Ching
;
生物科技學系
Bio-imaging of alpha-bungarotoxin binding to target cell by carboxylated nanodiamond
(2008-04-01)
Chao, Jui-I
;
Liu, Kuang-Kai
;
Chen, Mei-Fang
;
Chen, Po-Yi
;
Lee, Tony J. F.
Laser induced popcornlike conformational transition of nanodiamond as a nanoknife
(2008-07-21)
Chang, Chia-Ching
;
Chen, Pei-Hsin
;
Chu, Hsueh-Liang
;
Lee, Tzu-Cheng
;
Chou, Ching-Chung
Nanodiamond (ND) is surrounded by layers of graphite on its surface. This unique structure feature creates unusual fluorescence spectra, which can be used as an indicator to monitor its surface modification. Meanwhile, the impurity, nitroso (C - N = O) inside the ND can be photolyzed by two-photon absorption, releasing NO to facilitate the formation of a sp(3) diamond structure in the core of ND and transforming it into a sp(2) graphite structure. Such a conformational transition enlarges the size of ND from 8 to 90 nm, resulting in a popcornlike structure. This transition reaction may be useful as nanoknives in biomedical application. (c) 2008 American Institute of Physics.
Nano-manipulation on cancer cells by protein-nanodiamond complex.
(2007-01-01)
Chang, Chia-Ching
;
Chao, Jui-I
;
Ho, Yen-Peng
;
Sun, Ken-Wen
;
Cheng, Chia-Liang