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胆碱脱氢酶（ＣＤＨ）蛋白质部分内源荧光发射峰在３３５ｎｍ，并不受底物的影响，但底物可改变辅基ＦＡＤ部分的内源荧光光谱。应用ＦＴＩＲ技术研究了增溶ＣＤＨ的二级结构，其结果如下：５３．４％α－螺旋，２４．５％β－片层，１３．９％３１０－螺旋及０．５％β－回折。在ＣＤＨ处于非底物结合状态时，分子内部结构表现为α－螺旋以及β－片层优势构象，呈现出球状蛋白样的空间结构特征。在与底物作用过程中，３１０－螺旋的比例逐渐上升至４２％左右，与此同时α－螺旋结构则降低到３５％。提示了底物诱导ＣＤＨ分子内部发生了蛋白分子的重新折叠。
Choline dehydrogenase (CDH) protein partial endogenous fluorescence emission peak at 335nm, is not affected by the substrate, but the substrate can change the endogenous fluorescence of the prosthetic FAD part of the spectrum. Secondary structure of solubilized CDH was studied using FTIR technique with the following results: 53.4% α-helix, 24.5% β-sheet, 13.9% 310-helix and 0.5% β-sheet. When CDH was in the non-substrate binding state, the internal structure of the molecule showed the predominant conformation of α-helix and β-sheet, presenting a globular protein-like spatial structure. During the interaction with the substrate, the proportion of 310-helix gradually increased to about 42%, while the α-helical structure decreased to 35%. Suggesting that substrates induce the refolding of protein molecules within the CDH molecule.