| CHO | Chinese hamster ovary |
| K179A | Lys179 mutant of H1 receptor to alanine |
| K191A | Lys191 mutant of H1 receptor to alanine |
| K179A + K191A | Both Lys179 and Lys191 mutant of H1 receptor to alanine |
| WT | Wild-type H1 receptor |
| CHO | Chinese hamster ovary |
| K179A | Lys179 mutant of H1 receptor to alanine |
| K191A | Lys191 mutant of H1 receptor to alanine |
| K179A + K191A | Both Lys179 and Lys191 mutant of H1 receptor to alanine |
| WT | Wild-type H1 receptor |