本文用紫外差光谱和圆二色性光谱法对红曲霉葡萄糖淀粉酶的两个主要分子型E_3和E_4的构象作了初步探讨。发现竞争性抑制剂麦芽糖醇引起的酶的紫外差光谱主要是由色氨酸残基贡献的,E_3和E_4分子中的色氨酸残基对溶剂有不同程度的暴露,E_3分子中有31％暴露于乙二醇,21％暴露于聚乙二醇;E_4分子中有47％暴露于乙二醇,19％暴露于聚乙二醇。由远紫外CD光谱计算出E_3和E_4分子中的α-螺旋含量分别为22.8和15.3％,E_3子比E_4分子有较为紧密的构象。 In this paper, UV spectroscopy and circular dichroism spectroscopy of Monascus glucoamylase two main molecular conformation E_3 and E_4 made a preliminary study. It was found that UV-Vis spectra of the competitive inhibitor maltitol were mainly contributed by tryptophan residues, tryptophan residues in E_3 and E_4 molecules exposed to different degrees of solvent, 31% Exposure to ethylene glycol, 21% exposure to polyethylene glycol; 47% of the E_4 molecules were exposed to ethylene glycol and 19% to polyethylene glycol. The α-helix contents of E_3 and E_4 were 22.8% and 15.3%, respectively, from the far-UV CD spectrum, and the E_3 was more conformational than the E_4.