Identification of prion proteins by tandem mass spectrometry
The amyloid identification procedure (TAPI) was performed on the isogenic yeast strain pair, 74D-694 [PSI+][RNQ+] and [psi-][rnq-]. The trypsin-treated fractions were analyzed using the in-house mass spectrometer (two left columns) or by commercial service (Keck Biotechnology Resource Laboratory at Yale University; two right columns). Samples with asterisks (*) were treated more thoroughly with SDS to remove the majority of ribosomal proteins (marked by italics). The hits are arranged by protein score. Bold type indicates known prion proteins.