TABLE 1.
HCMV gB mutants utilized for study of the role of AD-1 in oligomerization
| gB mutant | Mutation | Phenotype
|
|||
|---|---|---|---|---|---|
| AD-1a | Mab 27-39b | Oligomerizationc | Cleavage | ||
| Wild type | None | + | + | + | + |
| ΔgB483 | Deletion of aa 484-907 | − | − | − | − |
| ΔgB781 | Deletion of aa 782-907 | + | + | + | + |
| ΔgB651 | Deletion of aa 652-907 | + | + | + | + |
| ΔgB642 | Deletion of aa 643-907 | + | +/− | + | NTe |
| ΔgB635 | Deletion of aa 636-907 | + | − | + | NT |
| ΔgB628 | Deletion of aa 629-907 | − | − | − | NT |
| ΔgBAD-1 | Deletion of aa 560-640 | − | − | − | NT |
| ΔgB55 | Deletion of aa 1-473d | + | − | − | NT |
| ΔgBc508s | Cys→Ser aa 508 | + | − | NT | − |
| ΔgBc550s | Cys→Ser aa 550 | + | − | NT | − |
| ΔgBc573s | Cys→Ser aa 573 | − | − | − | − |
| ΔgBc610s | Cys→Ser aa 610 | − | − | − | − |
Expression of AD-1 defined by reactivity with AD-1-specific Mabs, 7-17, 27-156, 27-180, and 27-78. gB expression was confirmed either by reactivity with the above antibodies, by Mab 58-15, which is directed at epitope in extreme C terminus, or by Mab 758, which is reactive with AD-2 in the amino terminus of gB.
Mab 27-39 has been shown to recognize a conformation-dependent binding site that is expressed on oligomeric forms of gB (14).
Oligomerization determined by sedimentation in sucrose gradients as described in Materials and Methods.
Although the ΔgB55 mutant was shown to be glycosylated, amino acid sequencing has not been carried out to determine if the authentic leader sequence of gB was cleaved during synthesis of this molecule.
NT, not tested.