Fogolari Federico, Tosatto Silvio C E
Dipartimento di Scienze e Tecnologie Biomediche, Università di Udine, Piazzale Kolbe 4, 33100 Udine, Italy.
Protein Sci. 2005 Apr;14(4):889-901. doi: 10.1110/ps.041004105.
Accurate free energy estimation is needed in many predictive tasks. The molecular mechanics/Poisson-Boltzmann solvent accessible surface area (MM/PBSA) approach has proven to be accurate. However, the correlation between the estimated free energy and the distance (e.g., root mean square deviation [RMSD]) from the most stable conformation is hindered by the strong free energy dependence on minor conformational variations. In this paper, a protocol for MM/PBSA free energy estimation is designed and tested on several loop decoy sets. We show that further integration of MM/PBSA free energy estimator with the colony energy approach makes the correlation between the free energy and RMSD from the native structure apparent, for the test sets on which it could be applied. Our results suggest that (1) the MM/PBSA free energy estimator is able to detect native-like structures for most decoy sets, and (2) application of the colony energy approach greatly hampers the MM/energy strong dependence on minor conformational changes.
在许多预测任务中都需要精确的自由能估计。分子力学/泊松-玻尔兹曼溶剂可及表面积(MM/PBSA)方法已被证明是准确的。然而,由于自由能对微小构象变化的强烈依赖性,估计的自由能与距最稳定构象的距离(例如均方根偏差[RMSD])之间的相关性受到阻碍。本文设计了一种MM/PBSA自由能估计方案,并在几个环诱饵集上进行了测试。我们表明,对于可以应用的测试集,将MM/PBSA自由能估计器与群体能量方法进一步整合,使得自由能与距天然结构的RMSD之间的相关性变得明显。我们的结果表明:(1)MM/PBSA自由能估计器能够检测大多数诱饵集的类天然结构;(2)群体能量方法的应用极大地削弱了MM/能量对微小构象变化的强烈依赖性。