BLOIS M S, ZAHLAN A B, MALING J E
Biophys J. 1964 Nov;4(6):471-90. doi: 10.1016/s0006-3495(64)86797-7.
Electron spin resonance (e.s.r.) observations of squid melanin have been conducted over the temperature range 500 degrees K to 4.2 degrees K, and the effect of various chemical treatments of the melanin upon the e.s.r. spectrum has been studied. The findings have shown that the paramagnetism of this melanin follows the Curie Law from 500 degrees K to 4.2 degrees K, that the spin signal can be eliminated by the addition of Cu(++) to the melanin, and that the optical and e.s.r. absorptions of melanin are independent since either can be reduced or eliminated without affecting the other. Similar studies on synthetic melanins produced by autoxidation or by enzymatic oxidation of a number of biphenols were carried out. It was found that the e.s.r. signals of these synthetic melanins were strikingly similar (with respect to line width, line shape, and g-value) with those of squid melanin. It is concluded that the unpaired electrons observed are associated with trapped free radicals in the melanin polymer, that the biosynthesis of melanin may involve a free radical mechanism, and that these physical data are in accord with the concept of Nicolaus that melanin is a highly irregular, three-dimensional, polymer.
已在500开尔文至4.2开尔文的温度范围内对鱿鱼黑色素进行了电子自旋共振（e.s.r.）观测，并研究了黑色素的各种化学处理对e.s.r.光谱的影响。研究结果表明，这种黑色素的顺磁性在500开尔文至4.2开尔文范围内遵循居里定律，向黑色素中添加Cu(++)可消除自旋信号，并且黑色素的光学吸收和e.s.r.吸收相互独立，因为其中任何一种吸收都可以在不影响另一种吸收的情况下降低或消除。对通过多种双酚的自氧化或酶氧化产生的合成黑色素进行了类似研究。发现这些合成黑色素的e.s.r.信号（在线宽、线形和g值方面）与鱿鱼黑色素的信号极为相似。得出的结论是，观察到的未成对电子与黑色素聚合物中捕获的自由基有关，黑色素的生物合成可能涉及自由基机制，并且这些物理数据与尼古劳斯的观点一致，即黑色素是一种高度不规则的三维聚合物。
