Table 2.
Antibody epitope mapping of SARS-CoV N protein with mAbs.1
| mAb2 | Flow cytometry results3 | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Full-length N (1–422) | NND14 (1–213) | NND13 (1–120) | NNDC1 (68–213) | NT1 (1–69) | NT2 (68–120) | NT3 (119–213) | NNDC2 (214–422) | NT4 (212–341) | NT5 (337–422) | ||||||||||
| M1 | + + | + + + | − | + + | − | − | + | − | − | − | |||||||||
| M2 | − | − | − | − | − | − | − | + + | − | − | |||||||||
| M3 | + + + | + + + | + + + | − | + + + | − | − | − | − | − | |||||||||
| M4 | + + | + + + | − | + + | − | − | − | − | − | − | |||||||||
| M5 | + + | + + + | − | + + | − | − | − | − | − | − | |||||||||
| M6 | + + | + + + | − | + + | − | − | + | − | − | − | |||||||||
| M7 | + + | + + + | − | + + | − | − | + | − | − | − | |||||||||
| M8 | − | − | − | − | − | − | − | + + | − | − | |||||||||
| M9 | + + + | + + + | + + + | − | + + + | − | − | − | − | − | |||||||||
| M10 | − | − | − | − | − | − | − | + + + | − | + + + | |||||||||
| M11 | − | − | − | − | − | − | − | + + + | − | + + + | |||||||||
| M12 | − | − | − | − | − | − | − | + + | − | − | |||||||||
| M13 | − | − | − | − | − | − | − | + + + | + + + | − | |||||||||
| M14 | − | − | − | − | − | − | − | + + + | − | − | |||||||||
Ten variable fragments distributed on the N protein were displayed on the EBY100 yeast cell surface to measure binding with the mAbs. The numbers in parentheses represent the amino acid numbers of the start and stop positions on the N protein.
The 14 mAbs produced in this study were used in this assay.
The fluorescence intensities of the various yeast-displayed fusion proteins binding to the 14 mAbs determined by flow cytometry were calculated by dividing the fluorescence intensity obtained for the individual fusion proteins by the fluorescence intensity obtained for the yeast expressing empty vector pYD1. Values with a ratio ≥2 were considered positive: −, negative result (ratio <2); +, weak but detectable positive signal (ratio 2–5); + +, intermediate positive signal (ratio 5–10); + + +, strong positive signal (ratio >10).