Table 1.
Energetic analysis of 48G7 antibody–hapten complex formations
| Germ line | Mature | |
|---|---|---|
| 〈ΔEelec〉 | −304.9 (2.5) | −349.1 (1.5) |
| 〈ΔEvdw〉 | −35.9 (0.5) | −35.5 (0.4) |
| 〈ΔEmm〉 | −340.8 (2.4) | −384.6 (1.4) |
| ΔGnp | −4.4 (0.0) | −4.2 (0.1) |
| ΔGPB | 317.6 (2.2) | 354.0 (1.2) |
| ΔGsolv | 313.3 (2.2) | 349.6 (1.2) |
| ΔGelec,tot | 12.7 (0.9) | 4.8 (0.5) |
| ΔGtot | −27.5 (0.6) | −35.0 (0.5) |
| −TΔS | 18.4 | 19.3 |
| ΔGbind | −9.1 | −15.7 |
Values in parentheses are SEM.
Results are mean energies (in kcal/mol) and SEM from 50 equally spaced “snapshot” configurations of a 500-ps MD simulation 〈ΔEmm〉. Each snapshot contains only the solute, which consists of all antibody and hapten atoms, including hydrogens. Definitions of the remaining energetic components are as follows: 〈ΔEelec〉 = electrostatic molecular-mechanical energy; 〈ΔEvdW〉 = van der Waals molecular-mechanical energy; 〈ΔEmm〉 = total molecular-mechanical energy (〈ΔEelec〉 + 〈ΔEvdW〉 + 〈ΔEint〉); ΔGnp = nonpolar contribution to the solvation energy; ΔGPB = electrostatic contribution to the solvation energy calculated by the PB approach; ΔGsolv = total solvation energy (ΔGPB + ΔGnp), ΔGelec,tot = total electrostatic energy (〈ΔEelec〉 + ΔGPB); ΔGtot = total energy without solute entropic contribution (〈ΔEmm〉 + ΔGsolv); − TΔS = solute entropic contribution, where T = temperature and S = sum of translational, rotational, and vibrational entropies; and ΔGbind = total energy with solute entropic contribution (ΔGtot − TΔS). Energetic contributions for the unbound antibody, unbound hapten, and antibody-hapten complex states in both the germ line and mature systems are shown in Tables 5 and 6, respectively, of supplementary material (see www.pnas.org).