High-field 19.6 T 27Al solid-state MAS NMR of in vitro aluminated brain tissue
The combination of 27Al high-field solid-state NMR (19.6 T) with rapid spinning speeds (17.8 kHz) is used to acquire 27Al NMR spectra of total RNA human brain temporal lobe tissues exposed to 0.10mM Al 3+ (as AlCl3) and of human retinal pigment epithelial cells (ARPE-19), grown in 0.10mM AlCl3. The spectra of these model systems show multiple Al3+ binding sites, good signal/ noise ratios and apparent chemical shift dispersions. A single broad peak (-3 to 11 ppm) is seen for the aluminated ARPE-19 cells, consistent with reported solution-state NMR chemical shifts of Al-transferrin. The aluminated brain tissue has a considerably different 27Al MAS NMR spectrum. In addition to the transferrin-type resonance, additional peaks are seen. Tentative assignments include: -9 to -3 ppm, octahedral AlO6 (phosphate and water); 9 ppm, condensed AlO6 units (Al-O-Al bridges); 24 ppm, tetrahedral AlO 3N and/or octahedral Al-carbonate; and 35 ppm, more N-substituted aluminum and /or tetrahedral Alo4. Thus, brain tissue is susceptible to a broad range of coordination by aluminum. Furthermore, the moderate 27Al CQ values (all less than 10 MHz) suggest future NMR studies may be performed at 9.4 T and a spin rate of 20kHz. © 2004 Elsevier Inc. All rights reserved.
Publication Source (Journal or Book title)
Journal of Magnetic Resonance
Bryant, P., Lukiw, W., Gan, Z., Hall, R., & Butler, L. (2004). High-field 19.6 T 27Al solid-state MAS NMR of in vitro aluminated brain tissue. Journal of Magnetic Resonance, 170 (2), 257-262. https://doi.org/10.1016/j.jmr.2003.12.013