Identification and genomic localization of a pseudorabies glycoprotein via expression in Escherichia coli

A glycoprotein (gp-88) secreted by pseudorabies virus (PRV) infected cells was isolated and purified. Anti gp-88 antibodies were used to screen an expression library constructed in Escherichia coli using genomic PRV DNA. Two positive clones were identified and the cloned genetic information was used to localize the corresponding gene in the unique short region of the PRV genome. Antibodies to the glycoprotein were also used to identify the unglycosylated precursor as synthesized in an in vitro translation system. A major precursor of 65 kDa was detected. Although the glycoprotein described here was not found as a major structural glycoprotein of the virion, antibodies to gp-88 are able to neutralise viral activity in vitro. The possible relationship with known glycoproteins of PRV is discussed.