Aime S, Fasano M, Terreno E, Groombridge C J
Dipartimento di Chimica Inorganica, Universita' di Torino, Italy.
Pigment Cell Res. 1991 Dec;4(5-6):216-21. doi: 10.1111/j.1600-0749.1991.tb00443.x.
This paper deals with the nuclear magnetic resonance characterization of a soluble derivative (melanin free acid) of Sepia melanin obtained by a peroxidative treatment of the parent (insoluble) species. High resolution 13C and 15N solid state NMR spectroscopies allow the assessment of the chemical changes occurring in the macromolecule upon solubilization. 1H and 13C NMR solution spectra are discussed in light of the results obtained from the solid state spectra. Furthermore, the coordination properties of melanin have been investigated through 27Al NMR spectroscopy and proton relaxation enhancement studies of the paramagnetic gadolinium complex of melanin free acid. Through these experiments it has been possible to evaluate the molecular reorientational time tau R (and from it an estimated molecular weight close to 20 KDa) and the strength of the metal-macromolecule interaction.
本文论述了通过对母体（不溶性）乌贼墨黑色素进行过氧化处理而获得的一种可溶性衍生物（黑色素游离酸）的核磁共振表征。高分辨率的13C和15N固态核磁共振光谱法可用于评估大分子在溶解过程中发生的化学变化。根据固态光谱获得的结果对1H和13C核磁共振溶液光谱进行了讨论。此外，通过27Al核磁共振光谱法以及对黑色素游离酸的顺磁性钆配合物的质子弛豫增强研究，对黑色素的配位性质进行了研究。通过这些实验，得以评估分子重排时间τR（并由此估算出接近20 kDa的分子量）以及金属-大分子相互作用的强度。
