Gabellieri E, Strambini G B, Gualtieri P
C.N.R., Istituto di Biofisica, Pisa, Italy.
Biophys Chem. 1988 May;30(1):61-7. doi: 10.1016/0301-4622(88)85004-x.
Information on the effects of crystallization upon the structure of liver alcohol dehydrogenase from horse is obtained from a comparison of the phosphorescence properties of its tryptophan residues in solution and in the crystalline state. In the crystalline state the red shift in the phosphorescence spectrum of the solvent-exposed Trp-15 attests to a decreased polarity of its environment consistent with its shielding away from the aqueous solvent probably through its involvement in an intermolecular contact. On the other hand, the triplet-state lifetime of Trp-314 which is buried deeply in the coenzyme-binding domain demonstrates that the flexibility of this region of the macromolecule is unaffected by crystallization; a conclusion supported also by the similarity in the rate of oxygen quenching of its phosphorescence. Given that lattice constraints strongly inhibit large-scale conformational changes these results allow us to identify the average solution structure with the 'open' conformer determined crystallographically.
通过比较马肝醇脱氢酶溶液状态和晶体状态下色氨酸残基的磷光特性，获得了有关结晶对其结构影响的信息。在晶体状态下，溶剂暴露的Trp-15磷光光谱中的红移证明其环境极性降低，这与其可能通过参与分子间接触而远离水性溶剂相一致。另一方面，深埋在辅酶结合域中的Trp-314的三重态寿命表明，大分子该区域的灵活性不受结晶影响；其磷光氧猝灭速率的相似性也支持了这一结论。鉴于晶格限制强烈抑制大规模构象变化，这些结果使我们能够将平均溶液结构与晶体学确定的“开放”构象体进行识别。
