Patent ID: 8173397

Claim:
A recombinant method for the preparation of an unglycosylated, folded, C-terminal fragment of a vertebrate complement cascade multidomain serine protease selected from the group of multidomain serine proteases consisting of a MBL-Associated Serine Protease-1 (MASP-1), a MBL-Associated Serine Protease-2 (MASP-21, a C1r protease and a C1s protease, wherein the domain structure of the multidomain serine protease C-terminal fragment is either a Complement Control Protein 1-Complement Control Protein 2-Serine Protease (CCP1-CCP2-SP), a Complement Control Protein 2-Serine Protease (CCP2-SPI, or a Serine Protease (SP), the method comprising: preparing a bacterial expression vector for expressing a cDNA insert encoding the complement cascade multidomain serine protease C-terminal fragment, wherein the 5′-terminus of the cDNA insert is fused in frame to a nucleotide sequence encoding an initiation codon and a peptide tag sequence that consists of the amino acid sequence set forth in either SEQ ID NO:19 or SEQ ID NO:20, said vector further comprising a promoter in operable linkage with said cDNA insert for expressing the encoded C-terminal fragment in bacterial host cells, transforming bacterial host cells with the vector, culturing the transformed bacterial host cells under conditions suitable for expression of said C-terminal fragment, producing said C-terminal fragment in the bacterial host cells, obtaining said produced C-terminal fragment as isolated inclusion bodies from the bacterial host cells, and refolding said produced C-terminal fragment from the inclusion bodies.