Exchange behavior of PrP(89–143, P101L) fibrils observed with NMR. A, shows the assigned 1H,15N HSQC spectrum of PrP(89–143, P101L) under the conditions of a typical 0-h time point, dissolving fibrils that had not been exposed to deuterium in DMSO containing 5% D2O and 0.03% TFA-D, pH* 5. The four ambiguous glycine residues are denoted with an asterisk. B, summary of the exchange behavior of PrP(89–143, P101L) fibrils.