NMR Spectra of Prions (IMAGE) Wiley Caption The molecular basis for prion infectivity is not yet understood. The NMR spectra of noninfectious and infectious amyloids of the prion-forming domain 218-289 of the fungal prion HET-s are clearly different (see picture) but are indicative for a cross-beta arrangement in both cases. The fibrils formed at pH 3 are not infectious because their molecular structure apparently differs substantially from that formed at physiological pH. Credit (C) Wiley-VCH 2008 Usage Restrictions Permission to use with appropriate credit and link to http://dx.doi.org/10.1002/anie.200704896 License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.