Thompson R E, Morrical S W, Campbell D P, Carper W R
Biochim Biophys Acta. 1983 Jun 29;745(3):279-84. doi: 10.1016/0167-4838(83)90059-6.
The conformational changes in glucose dehydrogenase are studied as a function of temperature and guanidinium chloride (GdmCl) concentration. The data were analyzed assuming a two-conformer model which gave similar results using either circular dichroism or enzyme activity. The free energy of denaturation was 0.94 kcal/mol from specific activity and 1.64 kcal/mol from circular dichroism measurements. The mid-point of the denaturation curve was 0.65 or 0.63 M GdmCl, as determined by specific activity or circular dichroism, respectively. The transition temperature, 6.4 degrees C, is close to that of a microsomal membrane phase change, a result that is consistent with the fact that glucose dehydrogenase contains lipid materials when isolated with a non-ionic detergent such as Triton X-114. As the temperature increased, the amount of beta-pleated sheet increased, and the alpha-helical content decreased, suggested that glucose dehydrogenase contains a stable core of beta-pleated sheet.
研究了葡萄糖脱氢酶的构象变化与温度和氯化胍（GdmCl）浓度的关系。假设采用双构象模型对数据进行分析，使用圆二色性或酶活性得到了相似的结果。根据比活性测定，变性自由能为0.94千卡/摩尔，根据圆二色性测量为1.64千卡/摩尔。变性曲线的中点分别由比活性或圆二色性测定为0.65或0.63 M GdmCl。转变温度为6.4℃，与微粒体膜相变温度相近，这一结果与用非离子去污剂如Triton X-114分离时葡萄糖脱氢酶含有脂质物质的事实一致。随着温度升高，β-折叠片的量增加，α-螺旋含量减少，表明葡萄糖脱氢酶含有稳定的β-折叠片核心。
