Goldstein R F
Computer Center, University of Illinois at Chicago 60612-7352.
Biophys J. 1994 May;66(5):1335-40. doi: 10.1016/S0006-3495(94)80923-3.
Folded proteins and spin glasses share various properties, such as seemingly random interactions between residues (spins), and one might presume that some generic behaviors of spin glasses would also be exhibited in a general way by proteins. But a comparison here shows that the side-chain conformation systems of apo-myoglobin and lysozyme are qualitatively different from specific closely related spin glass systems. This difference is manifest in the number of rotamers that can be identified as definitely not contributing to the global energy minimum. This identification is effected by using a significantly enhanced version of the Dead End Elimination theorem (Desmet, J., M. De Maeyer, B. Hazes, and I. Lasters. 1992. The dead-end elimination theorem and its use in protein side-chain positioning. Nature. 356:539-542), which is much more effective and efficient in eliminating rotamers. In several cases (for proteins, although not for spin glasses) this improved Dead End Elimination theorem succeeded in identifying the absolute global minimum of rotamer conformations, with no statistical uncertainty. The difference between protein and spin glass is due to correlations between the interactions of one residue pair with another pair, and probably will play an important role in the thermodynamic behavior of the protein system.
折叠蛋白与自旋玻璃具有多种共同特性，比如残基（自旋）之间看似随机的相互作用，因此有人可能会推测，自旋玻璃的某些一般行为在蛋白质中也会以一种普遍的方式表现出来。但此处的比较表明，脱辅基肌红蛋白和溶菌酶的侧链构象系统与特定的紧密相关自旋玻璃系统在性质上有所不同。这种差异体现在可确定对全局能量最小值无贡献的旋转异构体数量上。这种确定是通过使用死端消除定理（Desmet, J., M. De Maeyer, B. Hazes, and I. Lasters. 1992. The dead-end elimination theorem and its use in protein side-chain positioning. Nature. 356:539 - 542）的显著增强版本来实现的，该定理在消除旋转异构体方面更为有效和高效。在几种情况下（对于蛋白质而言，而非自旋玻璃），这种改进后的死端消除定理成功地确定了旋转异构体构象的绝对全局最小值，不存在统计上的不确定性。蛋白质与自旋玻璃的差异源于一个残基对与另一个残基对相互作用之间的相关性，并且可能会在蛋白质系统的热力学行为中发挥重要作用。
