ANTIBODIES SPECIFIC FOR UNGULATE PrP
The present invention provides antibodies that specifically bind with a high degree of binding affinity to a native ungulate PrP C and/or a denatured ungulate PrP Sc , but not to a native ungulate PrP Sc . Preferred antibodies find native bovine PrP C and treated PrP Sc but not native bovine PrP Sc and can be used in an assay to determine if a sample is infected with infectious prions, i.e. PrP Sc .
1 .- 20 . (canceled)
21 . A method of detecting PrP Sc in a sample, comprising the steps of:
treating a sample obtained from an ungulate to denature PrP Sc in the sample;
contacting the sample with a labeled antibody characterized by its ability to bind to denatured ungulate PrP Sc and native ungulate PrP C with a binding affinity K a of 10 8 l/mol or more; and to native ungulate PrP Sc with a binding affinity K a of 10 6 l/mol or less; and further characterized by not binding to PrP C of a mammal other than an ungulate; and
detecting the labeled antibody bound to denatured ungulate PrP Sc .
22 . A method of detecting PrP Sc in a sample, comprising the steps of:
treating a sample obtained from an ungulate to denature PrP Sc in the sample;
contacting the sample with a labeled antibody characterized by its ability to bind to denatured bovine PrP Sc and native bovine PrP C with a binding affinity K a of 10 8 l/mol or more and to native ungulate PrP Sc with a binding affinity K a of 10 6 l/mol or less; and
detecting the labeled antibody bound to denatured ungulate PrP Sc .
23 . A method of detecting PrP Sc in a sample, comprising the steps of:
treating a sample obtained from an ungulate to denature PrP Sc in the sample;
contacting the sample with a labeled antibody characterized by its ability to bind to denatured bovine PrP Sc and native bovine PrP C with a binding affinity K a of 10 8 l/mol or more and to native bovine PrP Sc with a binding affinity K a of 10 6 l/mol or less and further characterized by not binding to PrP C of a mammal other than an ungulate; and
detecting the labeled antibody bound to denatured ungulate PrP Sc .
24 . A method of detecting PrP Sc in a sample, comprising the steps of:
treating a sample obtained from an ungulate to denature PrP Sc in the sample;
contacting the sample with a labeled antibody which specifically binds to native ungulate PrP C , said antibody produced by the process comprising the steps of: synthesizing a library of antibodies on phage; panning the library against a sample by bringing the phage into contact with a composition comprising ungulate PrP proteins; isolating phage which bind native ungulate PrP C wherein the antibody is characterized by its ability to bind to denatured ungulate PrP Sc and native ungulate PrP C with a binding affinity K a of 10 8 l/mol or more and to native ungulate PrP Sc with a binding affinity K a of 10 6 l/mol or less; and analyzing the isolated phage to determine a sequence encoding an amino acid sequence to which the PrP C binds.
25 . The method of claim 24 , wherein the library of antibodies on phage are prepared by: immunizing a host mammal with PrP protein to create an immune response; extracting cells from the host mammal which cells are responsible for production of antibodies; isolating RNA from the cells of the host mammal; reverse transcribing the RNA to produce cDNA; amplifying the cDNA using a primer; and inserting the cDNA into a phage display vector such that antibodies are expressed on the phage.
26 . The method of claim 24 , wherein the process further comprises: panning antibodies against an antigen dispersed in a liposome.
27 . The method of claim 26 , wherein the antigen dispersed in a liposome is a peptide encoding an epitope of PrP C that is not available on PrP Sc .
28 . The method of claim 26 , wherein the antigen dispersed in a liposome comprises bovine residues 90-120.
29 . An assay, comprising:
a support surface; and
antibody characterized by its ability to bind to denatured ungulate PrP Sc and native ungulate PrP C with a binding affinity K a of 10 8 l/mol or more; and to native ungulate PrP Sc with a binding affinity K a of 10 6 l/mol or less; and further characterized by not binding to PrP C of a mammal other than an ungulate.
30 . The assay of claim 29 , wherein the antibody is characterized by an ability to bind 50% or more denatured ungulate PrP Sc in a liquid flowable sample.
31 . The assay of claim 29 , wherein a plurality of different antibodies are bound to the support surface and each antibody has a K a of 10 7 l/mole or more relative to PrP Sc .
32 . An assay, comprising:
a support surface; and
antibody characterized by its ability to bind to denatured bovine PrP Sc and native bovine PrP C with a binding affinity K a of 10 8 l/mol or more and to native ungulate PrP Sc with a binding affinity K a of 10 6 l/mol or less.
33 . The assay of claim 32 , wherein the antibody is characterized by an ability to bind 50% or more denatured ungulate PrP Sc in a liquid flowable sample.
34 . The assay of claim 32 , wherein a plurality of different antibodies are bound to the support surface and each antibody has a K a of 10 7 l/mole or more relative to PrP Sc .
35 . An assay, comprising:
a support surface; and
antibody characterized by its ability to bind to denatured bovine PrP Sc and native bovine PrP C with a binding affinity K a of 10 8 l/mol or more and to native bovine PrP Sc with a binding affinity K a of 10 6 l/mol or less and further characterized by not binding to PrP C of a mammal other than an ungulate.
36 . The assay of claim 35 , wherein the antibody is characterized by an ability to bind 50% or more denatured ungulate PrP Sc in a liquid flowable sample.
37 . The assay of claim 35 , wherein a plurality of different antibodies are bound to the support surface and each antibody has a K a of 10 7 l/mole or more relative to PrP Sc .