FIG. 1.

Schematic representation of truncated HSV gD produced by baculovirus-infected insect cells (33, 36). The protein has the honeybee melittin signal peptide (hatched box) in place of the wild-type gD signal for efficient translocation into the lumen of the endoplasmic reticulum, two extra amino acids (D and P) at the N terminus, and a histidine tag at the C terminus (33, 36, 44). The protein was truncated prior to the transmembrane region and has three N-CHO (balloons). The disulfide bonds are indicated by dashed lines. The functional regions of gD encompass the following amino acids: 27 to 43 for region I, 126 to 131 for region II, 225 to 246 for region III, and 277 to 300 for region IV (5).