Bacteriophage gene 3 protein compositions and use as amyloid binding agents
The invention relates to agents and to pharmaceutical compositions for reducing the formation of amyloid and/or for promoting the disaggregation of amyloid proteins. The compositions may also be used to detect amyloid.
1. A nucleic acid encoding a fusion protein that consists essentially of an amyloid-binding polypeptide linked directly or through a short peptide linker to an immunoglobulin IgG constant region, wherein the amyloid-binding polypeptide comprises at least one of:
(a) a wild type gene 3 protein (g3p) or a mutant thereof that retains the ability to bind to amyloid, or
(b) an amyloid-binding fragment of wild type g3p, or a mutant thereof that retains the ability to bind to amyloid.
2. The nucleic acid according to claim 1 , wherein the encoded amyloid-binding polypeptide is at least 95% identical to SEQ ID NO:1 or an amyloid-binding fragment of SEQ ID NO:1.
3. The nucleic acid according to claim 1 , wherein the encoded amyloid-binding polypeptide is at least 95% identical to the N1-N2 fragment of SEQ ID NO:1.
4. A vector comprising the nucleic acid of claim 1 .
5. A host cell comprising the vector of claim 4 .
6. A method of making a fusion protein that consists essentially of an amyloid-binding polypeptide linked directly or through a short peptide linker to an immunoglobulin constant region, wherein the amyloid-binding polypeptide comprises at least one of:
(a) a wild type g3p or a mutant thereof that retains the ability to bind to amyloid, or
(b) an amyloid-binding fragment of wild type g3p or a mutant thereof that retains the ability to bind to amyloid
comprising providing a host cell transformed with the vector of claim 4 , expressing the fusion protein encoded by the nucleic acid in the vector, and isolating the expressed fusion protein.
7. The host cell of claim 5 , wherein the host cell is selected from an insect cell, a plant cell, a fungal cell, a bacterial cell, an animal cell line, and a transgenic animal cell.
8. The host cell of claim 5 , wherein the host cell is selected from the group consisting of a Spodoptera frugiperda cell, an E. coli cell, a CHO cell, a CHO-derived cell, a COS cell, and a HeLa cell.
9. The host cell of claim 8 , wherein the host cell is a CHO cell or a CHO-derived cell.
10. The method of claim 6 , wherein the host cell is selected from an insect cell, a plant cell, a fungal cell, a bacterial cell, an animal cell line, and a transgenic animal cell.
11. The method of claim 6 , wherein the host cell is selected from the group consisting of a Spodoptera frugiperda cell, an E. coli cell, a CHO cell, a CHO-derived cell, a COS cell, and a HeLa cell.
12. The method of claim 6 , wherein the host cell is a CHO cell or a CHO-derived cell.