We present the use of H-2 magic-angle spinning (MAS) NMR on methyl-deuterated a-amino isobutyric acid (Aib) as a new method to obtain fast and accurate structural constraints on peptailbols in membrane-bound environments. Using nonoriented vesicle-reconstituted samples we avoid the delicate preparation of oriented samples, and the use of MAS ensures high sensitivity and thereby very fast acquisition of experimental spectra. Furthermore, given the high content (similar to 40%) of Aib in peptaibols and the fact that the amino acid Aib may be synthesized from cheap starting materials, even in the case of H-2, C-13, or N-15 labeling, this method is ideally suited for studies of the membrane-bound conformation of peptailbols.