Berichtigung: Formation of pH‐Resistant Monodispersed Polymer—Lipid Bilayer Nanodiscs

The University of Michigan found through its internal investigation1 that Sudheer Kumar Ramadugu, one of the co-authors on the paper, had falsified data the 14N NMR spectrum in Figure 1b in this Communication. The experiments have been repeated and the correct 14N NMR spectrum (Fig. 4b) confirms the magnetic alignment of the sample. The quadrupolar coupling has been corrected from 14, 7.6, and 2.9 kHz to 8.6, and 0 kHz, respectively. The corrected Figure 4 and associated caption are as follows. SMA-QA nanodiscs exhibit magnetic alignment and remarkable tolerance to pH and divalent metal ions. a) 31P and b) 14N NMR spectra of magnetically aligned large-size (ca. 30 nm diameter) nanodiscs made from DMPC:SMA-QA (1:0.25 w/w). c) 31P and d) 14N) NMR spectra of isotropic nanodiscs (ca. 10 nm diameter) made from DMPC:SMA-QA (1:1.5 w/w). e) A nanodisc illustrating the orientations of the lipid headgroup and polymer in magnetically aligned nanodiscs. f), g) SLS profiles of DMPC:SMAQA (1:1 w/w) nanodiscs showing remarkable stability towards pH (f) and the presence of Mg2+ and Ca2+ ions(g). The new data have also resulted in a few minor changes to the text: On page 1357 the sentences should read: The 14N NMR spectra of SMA-QA nanodiscs (ca. 30 nm) show three peaks corresponding to quadrupolar coupling values of about 8.6, and 0 kHz (Figure 4b). The observed quadrupolar coupling magnitude of about 8.6 kHz arises from the choline group of DMPC. The observed 0 kHz quadrupolar coupling is likely to be from the quaternary ammonium group of the SMA-QA polymer. The SMA-QA polymer belt completely surrounds the lipid bilayer as shown in Figure 4e, which is similar to the orientations of detergent molecules in aligned bicelles.