Meneghini C, Morante S
Laboratori Nazionali di Frascati INFN, 00044 Frascati, Italy.
Biophys J. 1998 Oct;75(4):1953-63. doi: 10.1016/S0006-3495(98)77636-2.
A detailed study of the x-ray absorption spectrum of tetanus neurotoxin in the K-edge EXAFS region of the zinc absorber is presented that allows the complete identification of the amino acid residues coordinated to the zinc active site. A very satisfactory interpretation of the experimental data can be given if multiple scattering contributions are included in the analysis. Comparing the absorption spectrum of tetanus neurotoxin to that of two other structurally similar zinc-endopeptidases, thermolysin and astacin, in which the zinc coordination mode is known from crystallographic data, we conclude that in tetanus neurotoxin, besides a water molecule, zinc is coordinated to two histidines and a tyrosine.
本文对破伤风神经毒素在锌吸收体的K边扩展X射线吸收精细结构（EXAFS）区域的X射线吸收光谱进行了详细研究，该研究能够完整鉴定与锌活性位点配位的氨基酸残基。如果在分析中纳入多重散射贡献，就能对实验数据给出非常令人满意的解释。将破伤风神经毒素的吸收光谱与另外两种结构相似的锌内肽酶（嗜热菌蛋白酶和龙虾肌碱蛋白酶）的吸收光谱进行比较，已知这两种酶的锌配位模式可从晶体学数据获得，我们得出结论，在破伤风神经毒素中，除了一个水分子外，锌与两个组氨酸和一个酪氨酸配位。
