Zanotti G, D'Auria G, Paolillo L, Trivellone E
Centro di Studio per la Chimica del Farmaco del CNR, University of Rome, Italy.
Int J Pept Protein Res. 1988 Jul;32(1):9-20.
Amatoxin analogues with D and L-Ala substitutions in position 5 have been studied by means of 1- and 2-dimensional n.m.r. spectroscopy at 500 MHz. The assignment of all resonances for both analogues has been carried out mostly with the use of COSY and NOESY type experiments. Temperature coefficients for the amide NH protons have been measured and the data compared to known amatoxin structures. The results obtained demonstrate that the rigidity of the bicyclic amatoxin framework is preserved in the D and L-Ala5 analogues, although the temperature coefficients point to intramolecular hydrogen bonds stronger in the case of the L-Ala analogue. The 10-fold decrease of biological activity is discussed in terms of structural features involving also the Trp4 indole accessibility.
已通过在500兆赫下的一维和二维核磁共振光谱法研究了在第5位具有D和L-丙氨酸取代的鹅膏毒素类似物。两种类似物所有共振峰的归属主要通过COSY和NOESY类型实验完成。已测量了酰胺NH质子的温度系数，并将数据与已知的鹅膏毒素结构进行了比较。所得结果表明，双环鹅膏毒素骨架的刚性在D和L-Ala5类似物中得以保留，尽管温度系数表明L-丙氨酸类似物中分子内氢键更强。从涉及色氨酸4吲哚可及性的结构特征方面讨论了生物活性降低10倍的情况。
