Use of a recombinant protein containing major epitopes of hnRNP G to detect anti-hnRNP G antibodies in dogs with systemic lupus erythematosus.
The objective of this study was to express major epitopes of heterogeneous nuclear ribonucleoprotein G (hnRNP G) for detecting anti-hnRNP G antibodies in dogs with systemic lupus erythematosus (SLE). HnRNP G cDNA clone was isolated from HEp-2 cells, and a DNA fragment encoding immunodominant region (residues 189-272) of hnRNP G (hnRNP Gi) was subcloned into pET32 vector to construct a prokaryotic expression plasmid named pEThnRNPGi. After induction, Escherichia coli carrying pEThnRNPGi expressed a recombinant protein of 28 kDa, comprising recombinant hnRNP Gi and fusion tag. Purified recombinant hnRNP Gi protein was further analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and its identity was confirmed. Western blot analysis showed that recombinant hnRNP Gi was specifically recognized by anti-hnRNP G positive sera of SLE dogs, and not by negative control sera. In conclusion, recombinant hnRNP Gi protein expressed in this study may serve as a useful reagent to assist in the immunological diagnosis of canine SLE.
Lin
T-Y
TY
Graduate Institute of Veterinary Microbiology, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 40227, Taiwan, ROC.
Chan
L-C
LC
Fan
Y-H
YH
Lin
C-H
CH
Chow
K-C
KC
Lin
S-L
SL
Lan
J-L
JL
Lin
F-J
FJ
Chiou
S-H
SH