Bs. Yan et al., TRUNCATING THE PUTATIVE MEMBRANE ASSOCIATION REGION CIRCUMVENTS THE DIFFICULTY OF EXPRESSING HEPATITIS-C VIRUS PROTEIN E1 IN ESCHERICHIA-COLI, Journal of virological methods, 49(3), 1994, pp. 343-351
The putative El of hepatitis C virus (HCV) was expressed in Escherichi
a coli using a glutathione-S-transferase (GST) fusion protein system.
The full length El protein is difficult to express. A series of El DNA
fragments was generated and used for expression vector construction.
Fusion proteins containing the El C-terminal region could not be expre
ssed. When this region was truncated, the fusion proteins were synthes
ized to high levels. The possibility of this C-terminal region hamperi
ng the production of fusion protein tvas further explored. A construct
with this segment directly fused to the C-terminus of GST indeed gene
rated no detectable recombinant protein. According to the predicted st
ructure of El, this region may have membrane-associating properties. T
he expression results suggest a general approach to facilitate the pro
duction of viral membrane proteins in prokaryotes. Furthermore, these
recombinant El proteins generated as antigens were used for Western bl
otting with sera from HCV-infected individuals. It was found that El i
s antigenic during HCV natural infection.