Cooper A
Proc Natl Acad Sci U S A. 1981 Jun;78(6):3551-3. doi: 10.1073/pnas.78.6.3551.
Temperature-dependent dynamic processes in biological macromolecules can produce sharp and reversible transitions in spectroscopic properties that might be misinterpreted as evidence for thermally induced conformational changes. This provides a rational explanation for the paradoxical case of D-amino acid oxidase [D-amino-acid:oxygen oxidoreductase (deaminating), EC 1.4.3.3], for which a sharp fluorescence transition at 14 degrees C, not observed by sensitive calorimetry [Sturtevant, J. M. & Mateo, P. L. (1978) Proc. Natl. Acad. Sci. USA 75, 2584-2587], could be due to a dynamic quenching process of large activation energy, rather than a change in conformational state of the protein. Similar interpretations may be valid in other systems studied by experimental techniques that depend, directly or indirectly, on molecular relaxation processes.
生物大分子中与温度相关的动态过程可在光谱特性上产生尖锐且可逆的转变，而这些转变可能会被误解为热诱导构象变化的证据。这为D-氨基酸氧化酶[D-氨基酸：氧氧化还原酶（脱氨基），EC 1.4.3.3]这一矛盾案例提供了合理的解释，对于该酶，在14摄氏度时出现的尖锐荧光转变（灵敏量热法未观察到[斯特蒂文特，J. M. & 马特奥，P. L.（1978年）美国国家科学院院刊75，2584 - 2587]）可能是由于具有大活化能的动态猝灭过程，而非蛋白质构象状态的改变。类似的解释可能适用于其他通过直接或间接依赖分子弛豫过程的实验技术所研究的系统。
