TABLE 1.
Cldns with the chimeric second loop
The chimeric Cldns were expressed in HEK293 cells and examined for sensitivity to CPE, which was classified into three categories: highly sensitive (High), EC50 < 1 μg/ml; slightly sensitive (Low), 1 μg/ml ≤ EC50 < 30 μg/ml; and insensitive, 30 μg/ml ≤ EC50. The Cldn1 and Cldn4 genes used in these experiments were derived from human and monkey, respectively. The underlining in the sequences indicates the second extracellular loop predicted by Sosui. The CPE-SR is indicated by bold type. The EC50 values are the means ± S.D. (μg/ml) calculated from three independent experiments.
| Claudin | Amino acid sequence | EC50 | Sensitivity |
|---|---|---|---|
| Wild type | |||
| huCldn1 | 139WYGNRIVQEFYDPMTPVNARYEFGQALFTGW169 | 4.32 ± 2.94 | Low |
| mkCldn4 | 138WTAHNIIQDFYNPLVASGQKREMGASLYVGW168 | 0.18 ± 0.09 | High |
| Chimera | |||
| Cldn4-1(A) | WTAHNIIQDFYNPLVASGQKREFGQALFTGW | >30 | Insensitive |
| Cldn4-1(B) | WTAHNIIQDFYNPLVASGQKREMGQALFTGW | 0.50 ± 0.28 | High |
| Cldn4-1(C) | WTAHNIIQDFYNPLVASGQKREMGAALFTGW | 0.11 ± 0.01 | High |
| Cldn1-4-1(A) | WYGNRIVQEFYNPLVASGQKREMGASLYVGW | 0.65 ± 0.23 | High |
| Cldn1-4-1(B) | WYGNRIVQEFYNPLVASGQKREMGAALFTGW | 0.46 ± 0.29 | High |
| Cldn1-4-1(C) | WYGNRIVQEFYDPLVASGQKREMGAALFTGW | 3.42 ± 0.93 | Low |
| Cldn1-4-1(D) | WYGNRIVQEFYDPMVASGQKREMGAALFTGW | 2.08 ± 0.39 | Low |