Gayda J P, Bertrand P, Deville A, More C, Roger G, Gibson J F, Cammack R
Biochim Biophys Acta. 1979 Nov 23;581(1):15-26. doi: 10.1016/0005-2795(79)90216-2.
The ferredoxins are characterized by a strong temperature dependence of the electronic spin-lattice relaxation time T1. The measurement of this dependence above the liquid nitrogen temperature has been presented in earlier work [1] for the 2-iron-2-sulfur ferredoxin of the blue green alga Spirulina maxima. The different relaxation mechanisms which could be efficient in this range were briefly discussed. In the present paper, we extend the measurement of the temperature dependence of T1 to the low temperature range 1.25 to 30 K. From 1.25 K to 13 K, T1 is obtained by the saturating pulse method, whereas the continuous saturation method is used from 8 K to 30 K. The experimental conditions concerning these methods are discussed. The analysis of the temperature dependence curve over the whole range 1.25 K to 133 K shows clearly that different regions must be distinguished. For each region the possible relaxation processes and the corresponding vibrational modes are discussed.
铁氧化还原蛋白的特点是电子自旋 - 晶格弛豫时间T1对温度有强烈依赖性。在早期的工作[1]中，已经给出了液氮温度以上这种依赖性的测量结果，该测量针对蓝藻极大螺旋藻的2-铁-2-硫铁氧化还原蛋白。简要讨论了在此温度范围内可能有效的不同弛豫机制。在本文中，我们将T1对温度依赖性的测量扩展到1.25至30K的低温范围。从1.25K到13K，通过饱和脉冲法获得T1，而从8K到30K则使用连续饱和法。讨论了与这些方法相关的实验条件。对1.25K至133K整个温度范围的温度依赖性曲线分析清楚地表明，必须区分不同区域。针对每个区域讨论了可能的弛豫过程和相应的振动模式。
