Fusion proteins forming trimers
The present invention refers to fusion proteins comprising a neck region and carbohydrate recognition domain of a collectin trimerization domain, a linker element and an effector polypeptide. Further the invention refers to a nucleic acid encoding the said fusion protein. The fusion proteins, the nucleic acid, and the cell are suitable as pharmaceutical composition or for therapeutic, diagnostic and/or research applications as described herein.
1. A fusion protein comprising
(i) a collectin family trimerization domain consisting of the amino acid residues selected from the group consisting of: 217-375, 218-375, 219-375, 220-375, 221-375, 222-375, 223-375, 224-375, and 225-375 of SEQ ID NO: 21, optionally further consisting of an amino acid substitution at residue 355;
(ii) a linker element; and
(iii) CD27 ligand (CD27L) or a receptor binding domain thereof;
wherein said linker element has 25 or less amino acids.
2. The fusion protein claim 1 , wherein CD27L is located N-terminally of the collectin family neck region.
3. The fusion protein of claim 2 , wherein the linker element consists of amino acids glycine and serine.
4. The fusion protein of claim 3 , wherein (iii) comprises 51-193 or 56-193 SEQ ID NO: 7.
5. The fusion protein of claim 2 , wherein the linker has the amino acid sequence of SEQ ID NO: 33, which is (GSS)a(SSG)b(GSG)c, wherein a, b, c is each independently 0, 1, 2, 3, 4, 5 or 6 such that the linker has 25 or less amino acid.
6. The fusion protein of claim 2 , wherein the linker element has the amino acid sequence of SEQ ID NO: 56, which is GSSGSSGSSGSG.
7. The fusion protein of claim 2 , wherein the linker element has the amino acid sequence of SEQ ID NO: 34, which is GSSGSSGSSGS.
8. The fusion protein of claim 2 , further comprising an N-terminal signal peptide domain.
9. The fusion protein of claim 2 , further comprising a recognition/purification domain selected from the group consisting of a strep-tag domain and a poly-His domain.
10. The fusion protein of claim 2 , wherein (iii) is human CD27L having SEQ ID NO: 7.
11. The fusion protein of claim 2 , wherein the linker element has the amino acid sequence of SEQ ID NO: 35, which is GSS GSS GS.
12. The fusion protein of claim 1 , wherein the amino acid residue 355 in SEQ ID NO: 21 is optionally substituted to a polar amino acid selected from the group consisting of aspartic acid, glutamic acid, asparagine and glutamine.
13. A trimeric complex consisting of three identical fusion proteins of claim 1 .