Subject	Biochemistry and biophysics
Specific subject area	Membrane proteins, secondary structure determination and protein mobile fraction in lipidic cubic phase
Type of data	Figure and Table
How data were acquired	The purification and analytical size exclusion chromatography (SEC) was performed using a ÄKTA protein purification system. The CD spectra of thermal unfolding experiment and the secondary structure of nAChR-DC were acquired using Jasco CD J-1500 (Japan) equipped with a Julabo AWC100 temperature controller. Rectangular quartz cell with 1 mm pathlength (Jasco 0556) was used for the experiment. The FRAP data was obtained on a Zeiss Axio Observer LSM 800 confocal microscope with a Tokai hit microscope incubator temperature controller.
Data format	Raw, Filtered and Analyzed
Parameters for data collection	The nAChR-DC purification and analytical SEC elution profile was monitored at 280 nm. The nAChR-DC CD spectrometry for the secondary structure predictions were recorded in the wavelength range of 190-250 nm. The CD scale was 200 mdeg / 1.0 dOD with the digital integration time (D.I.T) of 4 seconds, a bandwidth of 1.00 nm and a data pitch of 0.1 nm. The scanning speed was 100 nm/min with 1 number of accumulations. Confocal microscopy was performed at 20°C with a 40X magnification objective. The laser bleaching intensity was set to 50% of the total power, followed by the scanning of a sequence of 568 images. Consequently, each sample was integrated within a three 14.0 μm region of interest (ROI) and one reference ROI without bleaching.
Description of data collection	The native nAChR was extracted from Topedo californica (Tc) electroplax tissue obtained from Aquatic Research Consultants, San Pedro CA, USA and purified using a sequential purification process according to our related research article [1]. The millidegrees values obtained from the CD instrument were converted into mean residue ellipticity using the cd capitol plotting tool program (https://capito.uni-jena.de) according to Wiedemann protocols [2]. Subsequently, the CD spectra were analyzed using the Beta Structure Selection (BeStSel) (http://bestsel.elte.hu/index.php) for the evaluation of secondary structural predictions according to Micsonai methods [3] FRAP data were collected 24 hrs. after plates were assembled. The average integrated intensity of bleached 14.0 μm ROI, was used to correct for photobleaching from irradiation during the image-acquisition sequence. Finally, the fractional fluorescence recovery, diffusion coefficient and ΔFFR value was calculated using the equations described by Padilla-Morales [4].
Data source location	Institution: University of Puerto Rico, San Juan, Puerto Rico
Data accessibility	Raw data can be retrieved from the Mendeley data repository: http://dx.doi.org/10.17632/hjmf3tgykz.1
Related research article	This data article is submitted as a companion paper to: Rafael Maldonado-Hernández, Orestes Quesada, José O. Colón-Sáez and José A. Lasalde-Dominicci, (2020) Sequential purification and characterization of Torpedo californica nAChR-DC supplemented with CHS for high-resolution crystallization studies, Analytical Biochemistry, 113887, https://doi.org/10.1016/j.ab.2020.113887.