scholarly journals Use of a purified and functional recombinant calcium-channel β4 subunit in surface-plasmon resonance studies

2002 ◽  
Vol 364 (1) ◽  
pp. 285-292 ◽  
Author(s):  
Sandrine GEIB ◽  
Guillaume SANDOZ ◽  
Kamel MABROUK ◽  
Alessandra MATAVEL ◽  
Pascale MARCHOT ◽  
...  

Native high-voltage-gated calcium channels are multi-subunit complexes comprising a pore-forming subunit Cav and at least two auxiliary subunits α2δ and β. The β subunit facilitates cell-surface expression of the channel and contributes significantly to its biophysical properties. In spite of its importance, detailed structural and functional studies are hampered by the limited availability of native β subunit. Here, we report the purification of a recombinant calcium-channel β4 subunit from bacterial extracts by using a polyhistidine tag. The purified protein is fully functional since it binds on the alpha1 interaction domain, its main Cav-binding site, and regulates the activity of P/Q calcium channel expressed in Xenopus oocytes in a similar way to the β4 subunit produced by cRNA injection. We took advantage of the functionality of the purified material to (i) develop an efficient surface-plasmon resonance assay of the interaction between two calcium channel subunits and (ii) measure, for the first time, the affinity of the recombinant His-β4 subunit for the full-length Cav2.1 channel. The availability of this purified material and the development of a surface-plasmon resonance assay opens two immediate research perspectives: (i) drug screening programmes applied to the Cav/β interaction and (ii) crystallographic studies of the calcium-channel β4 subunit.

2020 ◽  
pp. 44-49
Author(s):  
I. N. Pavlov

Two optical methods, namely surface plasmon resonance imaging and frustrated total internal reflection, are described in the paper in terms of comparing their sensitivity to change of refractive index of a thin boundary layer of an investigated medium. It is shown that, despite the fact that the theoretically calculated sensitivity is higher for the frustrated total internal reflection method, and the fact that usually in practice the surface plasmon resonance method, on the contrary, is considered more sensitive, under the same experimental conditions both methods show a similar result.


2010 ◽  
Vol 130 (7) ◽  
pp. 269-274 ◽  
Author(s):  
Takeshi Onodera ◽  
Takuzo Shimizu ◽  
Norio Miura ◽  
Kiyoshi Matsumoto ◽  
Kiyoshi Toko

PIERS Online ◽  
2008 ◽  
Vol 4 (7) ◽  
pp. 746-750 ◽  
Author(s):  
Bing-Hung Chen ◽  
Yih-Chau Wang ◽  
Jia-Hng Lin

2018 ◽  
Author(s):  
Yong Cao ◽  
Mark T. McDermott

<div> <div> <div> <p>Quantitative measurement of small-molecule metabolites is now emerging as an effective way to link the metabolite profile to disease state. Surface plasmon resonance (SPR) is a sensing platform that has demonstrated applicability for a large range of biomolecules. However, direct detection of small molecules with SPR challenges the refractive index based detection mechanism. Herein, we utilized an indirect detection format and developed an inhibition immunoassay for the quantitative measurement of 17β-estradiol (E2) using SPR. One competitor, BSA-E2 conjugate, was immobilized to the SPR chip via the reaction between the primary amino group of the conjugate and the succinimide group (NHS) introduced by the formation of a thiol-NHS monolayer on gold surface. Free E2 molecules compete with BSA-E2 on chip surface for binding sites provided by a monoclonal anti-E2 antibody. It was found the binding affinity of the antibody to BSA-E2 conjugate increases with decreasing surface coverage of BSA-E2 conjugate. Under optimal conditions, a sigmoidal calibration curve with a negative slope and a dynamic range from 10 pM to 2 nM was generated. The detection limit of the immunoassay is estimated to be 0.3 pM. Moreover, the immunoassay exhibits high specificity for E2 detection using estrone (E1) as a potential interference.</p></div></div></div>


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