Patent ID: 7884190

Claim:
A recombinant dimeric protein obtainable by the following method: a) transfecting host cells with a vector allowing expression of a nucleotide sequence coding for a fusion polypeptide, said fusion polypeptide comprising at least one fragment of the β chain of the human C4BP protein as defined in SEQ ID NO: 1, or a functional variant of said fragment being selected from the group consisting of: (a1) a functional variant whose sequence is modified with respect to SEQ ID NO: 1 by deletion of one or more amino acids not essential to the dimerization function and/or by conservative substitution of one or more amino acids essential to dimerization, provided less than 25% of the amino acids of SEQ ID NO: 1 have been deleted and/or substituted; (a2) a functional variant according to (a1), wherein the cysteines located at positions 10 and 24 of SEQ ID NO: 1, and the at least 3 amino acids upstream and downstream of each cysteine have been conserved; (a3) a functional variant whose sequence is modified with respect to SEQ ID NO: 1 by substitution of one of the cysteines located at positions 10 and 24 by a neutral amino acid chosen among the amino acids A, V, F, P, M, I, L and W, and at the same time, by substitution of another amino acid by a cysteine; (a4) a functional variant whose sequence is modified with respect to SEQ ID NO: 1 by insertion of a heterologous sequence of the β chain between the cysteines located at positions 10 and 24 of SEQ ID NO: 1; and (a5) a functional variant whose sequence is modified with respect to SEQ ID NO: 1 by deletion of amino acid residue(s) between the cysteines located at positions 10 and 24 of SEQ ID NO: 1; said fusion polypeptide further comprising a polypeptide which is heterologous to said β chain; b) culturing the transfected host cells under conditions which are suitable for expressing the nucleotide sequence coding for the fusion polypeptide and the covalent association of two fusion polypeptides in vivo to form a dimeric protein; and c) recovering the dimeric proteins formed.