FORS1 antigen expression after DNA transfection of a variety of expression constructs into COS1(B3GALNT1) cells analyzed by immunoperoxidase staining procedure
| . | . | . | Adjusted FORS1 antigen-positive cell % . | |||
|---|---|---|---|---|---|---|
| Gene name . | Tripeptide sequence . | Other amino acid substitutions . | Exp 1 . | Exp 2 . | Exp 3 . | FS activity . |
| M_GBGT1 | GlyGlyAla | — | 100 | 100 | 100 | +++++ |
| M_ABO-AB | GlyGlyAla | — | 68 | 29 | 66 | ++++ |
| H_ABO-A | LeuGlyGly | — | 0 | 0 | 0 | − |
| Met1Thr | 0 | 0 | 0 | − | ||
| Met20Thr | 0 | 0 | 0 | − | ||
| Met26Thr | 0 | 0 | 0 | − | ||
| Met43Thr | 0 | 0 | 0 | − | ||
| Met53Thr | 0 | 0 | 0 | − | ||
| Met69Thr | 1 | 1 | 7 | ++ | ||
| Met142Thr | 0 | 0 | 0 | − | ||
| Met1,69Thr | 0 | 0 | 2 | + | ||
| Met20,26Thr | 0 | 0 | 0 | − | ||
| Met1,20,26Thr | 0 | 0 | 0 | − | ||
| Met1,20,26,43,69Thr | 2 | 0 | 2 | + | ||
| Met1,20,26,53,69Thr | 3 | 2 | 2 | ++ | ||
| Met1,20,26,43,53,69Thr | 2 | 0 | 4 | + | ||
| Met69Ser | 1 | 0 | 5 | + | ||
| GlyGlyAla | — | 2 | 0 | 3 | + | |
| Met69Thr | 56 | 119 | 100 | +++++ | ||
| MetGlyAla | — | 0 | 0 | 0 | − | |
| Met69Thr | 0 | 0 | 0 | − | ||
| . | . | . | Adjusted FORS1 antigen-positive cell % . | |||
|---|---|---|---|---|---|---|
| Gene name . | Tripeptide sequence . | Other amino acid substitutions . | Exp 1 . | Exp 2 . | Exp 3 . | FS activity . |
| M_GBGT1 | GlyGlyAla | — | 100 | 100 | 100 | +++++ |
| M_ABO-AB | GlyGlyAla | — | 68 | 29 | 66 | ++++ |
| H_ABO-A | LeuGlyGly | — | 0 | 0 | 0 | − |
| Met1Thr | 0 | 0 | 0 | − | ||
| Met20Thr | 0 | 0 | 0 | − | ||
| Met26Thr | 0 | 0 | 0 | − | ||
| Met43Thr | 0 | 0 | 0 | − | ||
| Met53Thr | 0 | 0 | 0 | − | ||
| Met69Thr | 1 | 1 | 7 | ++ | ||
| Met142Thr | 0 | 0 | 0 | − | ||
| Met1,69Thr | 0 | 0 | 2 | + | ||
| Met20,26Thr | 0 | 0 | 0 | − | ||
| Met1,20,26Thr | 0 | 0 | 0 | − | ||
| Met1,20,26,43,69Thr | 2 | 0 | 2 | + | ||
| Met1,20,26,53,69Thr | 3 | 2 | 2 | ++ | ||
| Met1,20,26,43,53,69Thr | 2 | 0 | 4 | + | ||
| Met69Ser | 1 | 0 | 5 | + | ||
| GlyGlyAla | — | 2 | 0 | 3 | + | |
| Met69Thr | 56 | 119 | 100 | +++++ | ||
| MetGlyAla | — | 0 | 0 | 0 | − | |
| Met69Thr | 0 | 0 | 0 | − | ||
The experiments (Exp) were performed in triplicate. The original gene names are listed in the leftmost column. M_GBGT1, M_ABO-AB, and H_ABO-A are the mouse GBGT1 gene, mouse ABO gene, and the A allele of the human ABO gene, respectively. The tripeptide sequences at the codons corresponding to codons 266 to 268 of human AT/BT and the amino acid substitutions introduced are shown in the next 2 columns. The adjusted FORS1-positive cell percentages observed in the triplicate experiments (1-3) are shown in the next 3 columns. The numbers of cells positive with GFP, whose expression vector was cotransfected, were used to normalize FORS1 antigen positivity. The values are shown in percentage of the expression of the original mouse FS construct. The deduced FS activity is shown semiquantitatively in the rightmost column (−, no; +, very weak; ++, weak; +++, moderate; ++++, strong; +++++, very strong activity).