Rousseau D L, Argade P V
Proc Natl Acad Sci U S A. 1986 Mar;83(5):1310-4. doi: 10.1073/pnas.83.5.1310.
The photoproduct of carbon monoxide myoglobin generated at 4 K and lower has a resonance Raman spectrum characteristic of a high-spin heme but in which the high-frequency core size-sensitive lines are at lower frequency than those in the deoxy preparation. Such differences are not detected in the photoproduct generated at higher temperatures (50 K) or in that generated at room temperature with 10-nsec pulses. The data indicate that at the low temperature (4 K), the heme in the photoproduct is not fully relaxed, and from the data we conclude that the photoproduct has an expanded porphyrin core. We infer that the core size exceeds that in deoxymyoglobin because the rigid protein prevents the highspin iron atom from moving to its full out-of-plane displacement at the very low temperatures.
在4K及更低温度下生成的一氧化碳肌红蛋白光产物具有高自旋血红素的共振拉曼光谱特征，但其中高频核心尺寸敏感线的频率低于脱氧制剂中的频率。在较高温度（50K）下生成的光产物或在室温下用10纳秒脉冲生成的光产物中未检测到此类差异。数据表明，在低温（4K）下，光产物中的血红素没有完全弛豫，并且从数据中我们得出结论，光产物具有扩展的卟啉核心。我们推断核心尺寸超过了脱氧肌红蛋白中的核心尺寸，因为刚性蛋白质阻止了高自旋铁原子在非常低的温度下移动到其完全的平面外位移。
