Table 3. Calculated Thermochemical Quantities of Methylated H+KPGG Tautomers and Total Hydrogen-Bond Potential Energy Densitiesa.
| K Me | species | theory CCS | ΔE0 (%) | ΔH (%) | ΔG (%) | V(r) |
|---|---|---|---|---|---|---|
| 0 | K-trans-1 | 118.1 | 1.48 (8.3%) | 2.13 (2.7%) | 0 (100%) | –0.0807 |
| 0 | Nt-cis-1 | 114.3 | 0 (100%) | 0 (100%) | 0.72 (29.9%) | –0.1502 |
| 1 | K-trans-1 | 118.3 | 0 (100%) | 0 (100%) | 0 (100%) | –0.1095 |
| 1 | Nt-cis-1 | 116.6 | 2.54 (1.4%) | 2.07 (3.1%) | 3.19 (0.5%) | –0.1812 |
| 2 | K-trans-1 | 121.2 | 2.20 (2.5%) | 2.38 (1.8%) | 1.96 (3.7%) | –0.1425 |
| 2 | Nt-cis-1 | 119.4 | 0 (100%) | 0 (100%) | 0 (100%) | –0.1780 |
a
Leftmost column enumerates methyl groups attached to the lysine side-chain amino group. Theoretical cross sections averaged over 100 random number seeds, thermochemical quantities in kcal/mol and relative to lowest, with normalized Boltzmann populations in parentheses, calculated as described in Section 2. Total potential energy density summed over all hydrogen bonds, in a.u.; QTAIM data for all hydrogen bonds can be found in the Supporting Information CCS in Å2.