Patent ID: 8062895

Claim:
An in vitro method for detecting a target protein having a predominantly β-sheet secondary structure, comprising: forming a mixture by adding a propagation catalyst to a sample suspected of containing a target protein having a predominantly β-sheet secondary structure, wherein the propagation catalyst is a peptide that: (i) has a predominantly alpha-helix and/or random coil secondary structure and interacts with protein having a predominantly β-sheet secondary structure; (ii) undergoes a conformational shift that results in a decrease in alpha-helix and/or random coil secondary structure and an increase in β-sheet secondary structure upon contact with protein having a predominantly β-sheet secondary structure or upon contact with another such propagation catalyst that has undergone such a conformational shift; and (iii) is labeled with an optically detectable moiety; allowing the propagation catalyst and any target protein present in the sample to interact; and detecting any increase in β-sheet secondary structure in the mixture by detecting the optically detectable moiety, the increase being due, at least in part, to an increase in β-sheet secondary structure of the propagation catalyst, wherein any such increase indicates the presence of target protein in the sample.