Misfolded protein sensor method in body fluids

Abstract

A catalytic conformational sensor method for detecting abnormal proteins and proteinaceous particles. The method is based on the interaction of a peptide fragment or probe with an abnormal proteinaceous particle. The interaction catalyzes transformation of the probe to a predominately beta sheet conformation and allows the probe to bind to the abnormal proteinaceous particle. This in turn, catalyzes propagation of a signal associated with the test sample-bound probe. As a result signals can be propagated even from samples containing very low concentrations of abnormal proteinaceous particles as is the case in many body-fluid derived samples.

Description

BACKGROUND [0001] 1. Field of the Invention [0002] This invention relates generally to a catalytic conformational sensor method and application of such method for detecting proteins and proteinaceous particles; and more particularly to detecting misfolded or disease-associated proteins and proteinaceous particles. [0003] 2. Related Art [0004] This document claims priority of U.S. provisional patent applications, Ser. No. 60 / 295,456 filed on May 31, 2001; which is hereby wholly incorporated by reference. [0005] The present invention is not limited to the detection of proteins or peptides in infectious samples. It also includes detection of proteinaceous particles such as prions. Prions are small proteinaceous particles with no nucleic acids, thus are resistant to most nucleic-acid modifying procedures and proteases. They are infectious particles that play key roles in the transmission of several diseases such as Creutzfeldt-Jakob syndrome, transmissible spongiform encephalopathy (TSE...

AI Technical Summary

Benefits of technology

[0014] This invention overcomes many of the problems of prior art by using catalytic propagation to exploit conformational changes in proteins associated with a particular disease process, such as transmissible spongiform encephalopathy (TSE). Catalytic propagation basically amplifies the number of existing protein fragments causing aggregates to form. The aggregates of conformationally changed protein fragments are then easily detected using common analytical techniques. As a result, the present invention allows testing to be done using rapid and cost-effective analytical techniques, even on, heretofore difficult to detect, small sample sizes and is widely applicable to tissues and body fluids other than those found in brain. The invention is also relatively noninvasive in that it does not need to be performed post-mortem.

[0015] Moreover, results can easily and immediately interpreted using familiar analytical instrumentation. Additionally, the present invention can amplify a weak signal, thus can be successfully applied to small or weak samples such as those associated with body fluids; thereby opening the door to analysis of tissues and fluids for the elusive diseases discussed above.

Problems solved by technology

Drawbacks of tissue sampling include belated detection that is possible only after symptoms appear, necessary slaughter of affected animals, and results that takes days to weeks to complete.

This test is as reliable as the immunochemistry technique and is more rapid, yielding results in six to seven hours, but shares the drawbacks of the six-month lag time between PrPs accumulation (responsible for the gross morphology changes) in the brain and the display of clinical symptoms, along with the need for slaughter of the animal to obtain a sample.

All of these techniques require a large amount of infectious sample, and have the disadvantage of requiring off-site testing or a large financial investment in equipment.

The difficulty with all of the presently approved tests is that they are time consuming and are performed POST-MORTEM.

As can now be seen, the related art remains subject to significant problems, and the efforts outlined above—although praiseworthy—have left room for considerable refinement.

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