Ostuni A, Passarella S, Quagliariello E
Dipartimento di Biochimica e Biologia Molecolare, Università di Bari, Italy.
J Photochem Photobiol B. 1993 Oct;20(2-3):101-11. doi: 10.1016/1011-1344(93)80138-y.
To gain some insight into the mechanism by which red light-biosystem interaction occurs, an investigation was made of certain features of purified glutamate dehydrogenase from beef liver (E.C. 1.4.1.3.) irradiated with either an He-Ne laser (632.8 nm) or a red light-emitting diode (650 +/- 20 nm). In both cases the energy dose was 0.24 J cm-2. Significant changes in the glutamate dehydrogenase extinction coefficient measured at 275 nm, the capability of the enzyme to bind the reduced form of nicotinamide adenine dinucleotide (NADH), certain kinetic parameters, the pH and temperature dependence and the sensitivity to guanosine 5 triphosphate (GTP) and adenosine diphosphate (ADP) were found, probably due to the interaction of light with a protein domain containing a metal ion or ions. He-Ne laser and diode irradiation were found to differ with regard to their interaction with glutamate dehydrogenase. Interestingly, different effects were also found when an He-Ne laser and a non-coherent Xe-Hg lamp were used to irradiate glutamate dehydrogenase under the same experimental conditions. This confirms that non-coherent light at various power levels affects the isolated glutamate dehydrogenase.
为了深入了解红光与生物系统相互作用的机制，我们对用氦氖激光（632.8纳米）或红光发光二极管（650±20纳米）照射的牛肝纯化谷氨酸脱氢酶（E.C. 1.4.1.3.）的某些特性进行了研究。在这两种情况下，能量剂量均为0.24焦/平方厘米。发现在275纳米处测得的谷氨酸脱氢酶消光系数、酶结合烟酰胺腺嘌呤二核苷酸还原形式（NADH）的能力、某些动力学参数、pH和温度依赖性以及对鸟苷5-三磷酸（GTP）和二磷酸腺苷（ADP）的敏感性发生了显著变化，这可能是由于光与含有一个或多个金属离子的蛋白质结构域相互作用所致。发现氦氖激光和二极管照射在与谷氨酸脱氢酶的相互作用方面存在差异。有趣的是，在相同实验条件下，当用氦氖激光和非相干氙汞灯照射谷氨酸脱氢酶时，也发现了不同的效应。这证实了不同功率水平的非相干光会影响分离的谷氨酸脱氢酶。
