Table 1.
Tyrosine in HCA II interactions, H bonds, and distance to active-site Zn
| Tyr no. (distance from Zn, Å) | pH 6 holo (this work, 4y0j) | pH 7.8 holo (PDB ID code 3tmj) | pH 10 holo (PDB ID code 3kkx) | pH 7.5 apo (this work, 4q49) |
| 7 (7) | Neutral (HBD and HBA to 2 waters) | Neutral (bifurcated HBD to 2 waters) | Deprotonated/charged (HBA to water) | Neutral (HBD and HBA to 2 waters) |
| 40 (28) | Neutral (HBD to water) | Unchanged | Unchanged | Unchanged |
| 51 (14) | Neutral (*HBA to protonated His122) | Neutral (HBA to protonated His122) | Neutral (HBA to protonated His122) | Neutral (HBD to neutral His122) |
| 88 (17) | Neutral (HBD to –CO Asp139, HBA to 2 waters) | Neutral (HBD to –CO of Asp139, HBA to 2 waters) | Neutral (HBD to water) | Neutral (HBD and HBA to 2 waters) |
| 114 (18) | Neutral (HBD and HBA to 2 waters) | Unchanged | Unchanged | Unchanged |
| 128 (21) | Neutral (HBD to Asp139) | Unchanged | Unchanged | Unchanged |
| 191 (20) | Neutral (HBD to –CO of Lys45) | Unchanged | Unchanged | Unchanged |
| 194 (10) | Neutral (HBA to protonated His107, HBD to Ser29) | Neutral (HBA to protonated His107, HBD to Ser29) | Neutral (HBA to protonated His107, HBD to Ser29) | Neutral (HBD to neutral His107, HBA to Ser29) |