S of bution with the former, which distinctive buffers. We identified that dMagR-his bound to magIMAC-purified dMagR-his in probably final results from dMagR-bound iron in BL21-dMagR cells. IMAC show absorption at 280 nm (black line), absorption at 320 nm for iron ulfur cluster proteins As anticipated, this paramagnetic contribution increases with decreasing temperature, as netic beads line) and relative concentration of elution buffer B NaCl line). M (NH4)2SO4 (Sup(red dashed in between pH 51 in the presence of as much as two M (blue or 1 found for BL21-dMagR cells at 3.six only hindered at pH 12. our results clearly show plementary Figure S2). Binding was K (Figure 2c). Nonetheless,Depending on these final results, we that Tianeptine sodium salt custom synthesis overexpression robust Magnetize Bacterial be not hypothesize veryof intracellular dMagR to Cells explanation for MagR binding, rathermagnetic 2.2. Possible of MagR to ionic interactions does the exhibit a sufficiently robust than precise magnetic interactions. diamagnetic character with the E. coli cell, even at only 3.six K. contribution to overcome the3 ofFor magnetization studies, we overexpressed the Fe protein dMagR without having histag to about 17 of total soluble protein in E. coli (Figures 2a and S3). This higher intracellular content was also visible as a black rown coloration of BL21-dMagR cell biomass and its supernatant after cell disruption (Figure 2b). Quantification by SDS-PAGE densitometry (non-MagR impurities at Bomedemstat MedChemExpress around 14 kDa were excluded based on a respective unfavorable control) yielded an approximate intracellular, soluble dMagR concentration of 54 mg g-1 dry cell weight (DCW) or five.12 pg cell-1 (1 cell 9.5 10-13 g DCW ) equivalent to two.20 106 dMagR molecules cell-1. Having said that, putting a strong neodymium magnet (50 50 12.5 mm) near the BL21-dMagR biomass suspension at room temperature resulted in no observable movement of cells towards the magnet. We additional analyzed magnetization behavior with lyophilized cells by superconducting quantum interference device (SQUID) magnetometry. Determined by the vague expertise about MagR and its applicability in cells to interact with magnetic fields at ambient circumstances [8,9], we hypothesized that measurements at low temperatures of only 3.6, 20 and 120 K 1. Evaluation of clearer indication on aacomplex matrix. (a) SDS-PAGE evaluation of is due to Figure would give a MagR purification from a potential applicability in cells. That magnetic Figure 1. Evaluation ofMagR purification from complex matrix. (a) SDS-PAGE evaluation ofmagthe known temperature-dependent and clMagR-hisfrom cell disruption supernatant. White The netic bead purificationBlank, dMagR-his magnetic susceptibility disruption supernatant. White bead purification of of Blank, dMagR-his and clMagR-his from cell of magnetic materials. field-dependent isothermal magnetization measurements Equivalent a dominant of sample rectangles show respective target proteins in in the applied cell pellet. Equivalent volumes diamagrectangles show respective target proteins the applied cell pellet. revealed volumes of sample have been response of respective lane (1). The followingcells in a static are samples per lane external magnetic field for target neticapplied for eachBL21-Blanklane (1). The following samples per lane seenseeneacheach target have been applied for each and every respective and BL21-dMagR are for (emu/g lane L: protein ladder; lane 1 (3 ): solubilized cell pellet; lane emu ):=cell-free supernatant = electromagnetic unit per gram DCW; emu = 10-3 Am2; two (10 g-1 Am2 kg-1).