Method for detection of specific antibodies using ubiquitin fusion proteins
Disclosed are epitope-containing heat shock fusion proteins, DNA constructs encoding such fusion proteins, and methods of use. More specifically, disclosed are ubiquitin fusion proteins comprising ubiquitin fused to a plurality of identical or non-identical epitopes at specified locations.
1. A method for detecting the presence of specific antibodies in experimental or clinical samples, comprising:
a) providing a ubiquitin fusion protein selected from the group consisting of i) a ubiquitin fusion protein comprising ubiquitin fused to a single epitope-containing segment, the epitope-containing segment comprising two or more identical epitopes, ii) a ubiquitin fusion protein comprising ubiquitin fused to two or more non-contiguous epitope-containing segments, each epitope-containing segment comprising one or more identical epitopes, iii) a ubiquitin fusion protein comprising ubiquitin fused to a single epitope-containing segment comprising two or more identical epitopes, the epitope-containing segment being fused to the ubiquitin at fusion sites selected from the group consisting of the C-terminus of the ubiquitin protein wherein said fusion site is non-cleavable, the N-terminus of the ubiquitin protein or an internal fusion site of the ubiquitin protein and, iv) a ubiquitin fusion protein comprising ubiquitin fused to a single epitope-containing segment comprising two or more identical epitopes, the epitope-containing segment being fused to ubiquitin at the C-terminus wherein said fusion site is non-cleavable or the N-terminus of the ubiquitin protein, wherein one or more epitopes of steps (a)(i)-(a)(iv) are recognized by the antibody to be detected;
b) providing a sample suspected of comprising antibodies reactive with one or more epitopes of the ubiquitin fusion protein, said sample acquired from an experimental or clinical source;
c) forming an incubation mixture comprising the ubiquitin fusion protein of step a) and the sample of step b); and
d) detecting antibodies in the sample of step b) that bind to the epitope or epitopes of the ubiquitin fusion protein of step a) and wherein said epitopes of step a) are selected from the group consisting of HIV gp 120 V3 loop epitopes, GnRH epitopes and Growth Hormone epitopes.
2. The method of claim 1 , wherein said epitopes are HIV gp 120 V3 loop epitopes.
3. The method of claim 1 , wherein said epitopes are GnRH epitopes.
4. The method of claim 1 , wherein said epitopes are Growth Hormone epitopes.