We present ¹⁹F longitudinal and transverse relaxation studies for four differently fluorosubstituted l-tryptophans, which carry single F atoms in the indole ring, both in the context of the free amino acid and when located in the cyclophilin A protein. For the free 4F-, 5F-, 6F-, 7F-l-Trp, satisfactory agreement between experimentally measured and calculated relaxation rates was obtained, suggesting that the parameters used for calculating the rates for the indole frame are sufficiently accurate. We also measured and calculated relaxation rates for four differently ¹⁹F-tryptophan labeled cyclophilin A proteins, transferring the parameters from the free amino acid to the protein-bound moiety. Our results suggest that ¹⁹F relaxation data of the large and rigid indole ring in Trp are only moderately affected by protein motions and provide critical reference points for evaluating fluorine NMR relaxation in the future, especially in fluorotryptophan labeled proteins.

我们本¹⁹四个不同氟取代的F的经度和横向弛豫研究升-tryptophans，其携带在吲哚环的单F原子，无论是在游离氨基酸的上下文中，并且在亲环素A蛋白时。对于自由4F-，5F-，6F-，7F-升-Trp，令人满意的协议之间实验测得的，得到计算出的弛豫速率，这表明用于计算价格的吲哚帧的参数是足够精确的。我们还测量并计算了四种不同的¹⁹ F-色氨酸标记的亲环蛋白A蛋白的弛豫率，将参数从游离氨基酸转移到蛋白结合部分。我们的结果表明¹⁹Trp中大而刚性的吲哚环的F弛豫数据仅受到蛋白质运动的适度影响，并为评估未来的氟NMR弛豫提供了关键参考点，尤其是在氟色氨酸标记的蛋白质中。