Serikyaku S, Ishitani R
Group of Neuropharmacology, Josai University, Saitama, Japan.
Life Sci. 1988;42(2):207-14. doi: 10.1016/0024-3205(88)90684-4.
The effect of glutaraldehyde (and Azure A) on temperature-sensitive high-affinity [3H]tryptamine binding was investigated in rat brain synaptic plasma membranes. In the 0.01-0.1% concentration range, the glutaraldehyde pretreatment preferentially inhibited only the above-mentioned portion of the binding, whereas the posttreatment of this reagent had no effect. On the other hand, in cases of pretreatment or posttreatment, a concentration of glutaraldehyde as high as 0.1% was inactive on the basal [3H]ligand binding capacity of the membranes (i.e., temperature-independent binding). Furthermore, it was revealed that the Scatchard plot of [3H]tryptamine binding in membranes pretreated with glutaraldehyde (0.05%) conformed to a straight line, as did a similar plot of temperature-independent binding. And, it was interesting to find that the binding parameters (KD and Bmax values) of both samples corresponded closely to each other. On the contrary, in all concentrations, Azure A affected nonspecifically both the temperature-dependent and the independent [3H]tryptamine binding to the same degree, regardless of whether or not there was pretreatment or posttreatment. All these observations clearly demonstrate that an appropriate concentration (0.01-0.1%) of glutaraldehyde pretreatment specifically blocks the temperature-induced allosteric modifications of high-affinity [3H]tryptamine binding sites.
在大鼠脑突触质膜中研究了戊二醛（和天青A）对温度敏感的高亲和力[3H]色胺结合的影响。在0.01 - 0.1%的浓度范围内，戊二醛预处理仅优先抑制上述结合部分，而该试剂的后处理则无作用。另一方面，在预处理或后处理的情况下，高达0.1%的戊二醛浓度对膜的基础[3H]配体结合能力（即温度不依赖结合）无活性。此外，还发现用戊二醛（0.05%）预处理的膜中[3H]色胺结合的Scatchard图符合一条直线，与温度不依赖结合的类似图相同。而且，有趣的是发现两个样品的结合参数（KD和Bmax值）彼此非常接近。相反，在所有浓度下，天青A对温度依赖和不依赖的[3H]色胺结合均有非特异性影响，无论是否有预处理或后处理。所有这些观察结果清楚地表明，适当浓度（0.01 - 0.1%）的戊二醛预处理特异性地阻断了温度诱导的高亲和力[3H]色胺结合位点的变构修饰。
