Ikura T, Go N, Inagaki F
Department of Chemistry, Faculty of Science, Kyoto University, Japan.
Proteins. 1991;9(2):81-9. doi: 10.1002/prot.340090202.
In our previous paper we reported the conformation of melittin bound to perdeuterated dodecylphosphocholine micelles as studied by 1H NMR experiment and distance geometry calculation. No hydrogen bonds were taken into consideration explicitly in the calculation. However, mostly alpha-helical conformations were obtained as results of the calculation even with no explicitly assumed hydrogen bonds. In the present paper we refined the distance geometry calculation by incorporating hydrogen bonds suggested by the previous calculation. As a result, we obtained the conformation of melittin, which was consistent with both NMR data and the additional hydrogen bonding data. The alpha-helical rod in the refined conformation also has a kink at Thr-11 and Gly-12, but its bent angle is now a bit narrowly distributed in 135 degrees +/- 15 degrees. In the present study another distortion at Trp-19 and IIe-20 becomes conspicuous. The average root-mean-square displacement of atoms is now much smaller and is 1.5 A for all backbone atoms. In the present paper side chain conformations are also analyzed.
在我们之前的论文中，我们报道了通过¹H NMR实验和距离几何计算研究的蜂毒素与全氘代十二烷基磷酸胆碱胶束结合的构象。在计算中没有明确考虑氢键。然而，即使没有明确假设氢键，计算结果大多仍为α-螺旋构象。在本文中，我们通过纳入先前计算所建议的氢键来改进距离几何计算。结果，我们得到了与NMR数据和额外氢键数据均一致的蜂毒素构象。精细构象中的α-螺旋杆在Thr-11和Gly-12处也有一个扭结，但其弯曲角度现在在135°±15°范围内分布得更窄一些。在本研究中，Trp-19和Ile-20处的另一种扭曲变得明显。现在所有主链原子的平均均方根位移要小得多，为1.5 Å。在本文中还对侧链构象进行了分析。
