Zetta L, Hore P J, Kaptein R
Eur J Biochem. 1983 Aug 1;134(2):371-6. doi: 10.1111/j.1432-1033.1983.tb07577.x.
The photochemically-induced dynamic nuclear polarization technique has been used to investigate the access of a photoexcited flavin dye to tyrosyl and histidyl residues in [Met]enkephalin and human and camel beta-endorphins, both alone and in the presence of n-dodecylphosphorylcholine micelles. The results indicate that the mode of binding of Tyr-1, but not of residue 27, is similar in the two endorphins and differs from that of Tyr-1 in [Met]enkephalin. In human beta-endorphin, accessibility and mobility of Tyr-27 are strongly reduced in the presence of lipid at physiological pH, whereas in camel beta-endorphin His-27 becomes immobilized only at high pH. Moreover, nuclear Overhauser enhancement experiments suggest a rigidifying influence of the peptide on the polar head groups of the micelles.
光化学诱导动态核极化技术已被用于研究光激发的黄素染料对[甲硫氨酸]脑啡肽、人β-内啡肽和骆驼β-内啡肽中酪氨酸和组氨酸残基的接近情况，这些研究分别在单独存在以及存在正十二烷基磷酰胆碱胶束的条件下进行。结果表明，在两种内啡肽中，Tyr-1（而非第27位残基）的结合模式相似，且与[甲硫氨酸]脑啡肽中Tyr-1的结合模式不同。在人β-内啡肽中，在生理pH值下存在脂质时，Tyr-27的可及性和流动性会大幅降低，而在骆驼β-内啡肽中，His-27仅在高pH值时才会固定化。此外，核Overhauser增强实验表明该肽对胶束的极性头部基团有刚性化影响。
