无花果蛋白酶酸诱导类熔球态的表征

Characterization of acid-induced molten globule like state of ficin.

作者信息

Devaraj K B, Kumar Parigi Ramesh, Prakash V

机构信息

Department of Protein Chemistry and Technology, Central Food Technological Research Institute (A Constituent Laboratory of CSIR), Cheluvamba Mansion, KRS Road, Mysore 570020, India.

出版信息

Int J Biol Macromol. 2009 Oct 1;45(3):248-54. doi: 10.1016/j.ijbiomac.2009.05.008. Epub 2009 May 29.

DOI:10.1016/j.ijbiomac.2009.05.008

PMID:19482042

Abstract

Effect of pH on the conformational behaviour of ficin (EC 3.4.22.3), a cysteine protease from the latex of Ficus carica was monitored by circular dichroism, fluorescence spectroscopy, ANS binding and hydrodynamic studies. The results obtained from near- and far-UV CD, intrinsic fluorescence and ANS binding studies demonstrate that ficin exhibits the characteristic properties of molten globule at acidic conditions between pH 1.4 and 2.0. Ficin at pH 1.4 retained about approximately 74% secondary structure with a substantial loss of tertiary structure. The acid-induced state was found to have a compact shape as measured by Stokes radius on size exclusion chromatography.

摘要

通过圆二色性、荧光光谱、ANS结合和流体动力学研究监测了pH对无花果蛋白酶（EC 3.4.22.3）构象行为的影响，无花果蛋白酶是一种来自无花果乳胶的半胱氨酸蛋白酶。近紫外和远紫外圆二色性、内源荧光和ANS结合研究所得结果表明，无花果蛋白酶在pH 1.4至2.0的酸性条件下表现出熔球态的特征性质。pH 1.4时的无花果蛋白酶保留了约74%的二级结构，三级结构大量丧失。通过尺寸排阻色谱法测定的斯托克斯半径表明，酸诱导状态具有紧密的形状。