Palermo Nicholas Y, Csontos József, Murphy Richard F, Lovas Sándor
Department of Biomedical Sciences, Creighton University, Omaha, NE 68178, USA.
Int J Quantum Chem. 2008;108(4):814-819. doi: 10.1002/qua.21521.
Avian Pancreatic Polypeptide is a 36 residue protein that exhibits a tertiary fold. Results of previous experimental and computational studies indicate that the structure of aPP is stabilized more by non-bonded interactions than by the hydrophobic effect. Aromatic residues are known to participate in a variety of long range non-bonded interactions, with both backbone atoms and the atoms of other side-chains, which could be responsible, in part, for the stability of both the local secondary structure and the tertiary fold. The effect of these aromatic interactions on the stability of aPP was calculated using BHandHLYP/cc-pVTZ. Aromatic residues were shown to participate in multiple hydrogen bonded and weakly polar interactions in the secondary structure. The energies of the weakly polar interactions are comparable with those of hydrogen bonds. Aromatic residues were also shown to participate in multiple weakly polar interactions across the tertiary fold, again with energies similar to those of hydrogen bonds.
禽胰多肽是一种具有三级折叠结构的36个残基的蛋白质。先前的实验和计算研究结果表明，禽胰多肽的结构通过非键相互作用比通过疏水作用更稳定。已知芳香族残基参与多种长程非键相互作用，与主链原子以及其他侧链的原子相互作用，这可能部分地负责局部二级结构和三级折叠的稳定性。使用BHandHLYP/cc-pVTZ计算了这些芳香族相互作用对禽胰多肽稳定性的影响。结果表明，芳香族残基在二级结构中参与多个氢键和弱极性相互作用。弱极性相互作用的能量与氢键的能量相当。芳香族残基还被证明在三级折叠中参与多个弱极性相互作用，其能量同样与氢键的能量相似。
