Expression of anticardiolipin cofactor, human beta 2-glycoprotein I, by a recombinant baculovirus/insect cell system.
A full-length cDNA coding a human beta 2-glycoprotein I (beta 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 43,000) reactive with anti-beta 2-GPI antisera was produced in the insect cells and secreted into the culture medium. The recombinant beta 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 beta 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 beta 2-GPI. Thus, the beta 2-GPI expressed in insect cells is an immunologically active cofactor.
Igarashi
M
M
Microbiology Laboratory, Yamasa Corporation, Choshi, Japan.
Matsuura
E
E
Igarashi
Y
Y
Nagae
H
H
Matsuura
Y
Y
Ichikawa
K
K
Yasuda
T
T
Voelker
D R
DR
Koike
T
T
D000595:Amino Acid Sequence; D000818:Animals; D001053:Apolipoproteins / Q000235:genetics; D016367:Baculoviridae / Q000235:genetics*; D001483:Base Sequence; D002308:Cardiolipins / Q000276:immunology; D002460:Cell Line; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D015967:Gene Expression Regulation, Viral; D006023:Glycoproteins / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000276:immunology; D008969:Molecular Sequence Data; D009036:Moths; D021382:Protein Sorting Signals; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification*; D011995:Recombination, Genetic; D014162:Transfection; D053482:beta 2-Glycoprotein I
D001053:Apolipoproteins; D002308:Cardiolipins; D006023:Glycoproteins; D021382:Protein Sorting Signals; D011994:Recombinant Proteins; D053482:beta 2-Glycoprotein I