Open AccessExpression of anticardiolipin cofactor, human β 2 ‐glycoprotein I, by a recombinant baculovirus/insect cell system
Author(s) -
IGARASHI M.,
MATSUURA E.,
IGARASHI Y.,
NAGAE H.,
MATSUURA Y.,
ICHIKAWA K.,
YASUDA T.,
VOELKER D. R.,
KOIKE T.
Publication year - 1993
Publication title -
clinical & experimental immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.329
H-Index - 135
eISSN - 1365-2249
pISSN - 0009-9104
DOI - 10.1111/j.1365-2249.1993.tb06491.x
Subject(s) - sf9 , recombinant dna , spodoptera , biology , microbiology and biotechnology , glycoprotein , affinity chromatography , complementary dna , baculoviridae , peptide sequence , biochemistry , gene , enzyme
SUMMARY A full‐length cDNA coding a human β 2 ‐glycoprotein I (β 2 ‐GPI) was introduced into the baculovirus genome to construct a recombinant baculovirus. Spodoptera frugiperda (Sf9) cells were infected with the recombinant baculovirus. A protein (mol. wt 43000) reactive with anti‐β 2 ‐GPI antisera was produced in the insect cells and secreted into the culture medium. The recombinant β 2 ‐GPI was purified from the culture supernatant by sequential cardiolipin (CL)‐affinity column chromatography and gel filtration. The N‐terminal amino acid sequence of the protein was identical to that of the native β 2 :‐GPI purified from human sera, and a putative signal peptide was cleaved from the secreted form of the recombinant protein. The purified recombinant protein had a cofactor activity which enhances CL binding of anticardiolipin antibodies (aCL) in systemic lupus erythematosus (SLE) patients, as well as the native β 2 ‐GPI. Thus, the β 2 ‐GPI expressed in insect cells is an immunologically active cofactor.