Nabil Abdul, Aleem Sidek, Adyani Azizah, A. Halim, H. Kadir, Saad Tayyab
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引用次数: 2
摘要
目的:研究商品无花果素(CF)在盐酸胍(GdnHCl)、尿素、乙醇和酸性pH条件下的构象稳定性,并与报道的纯化商品无花果素的主要组分(MFF)的构象稳定性进行比较。利用远紫外和近紫外CD光谱信号、本征荧光、丙烯酰胺猝灭和酶活性研究化学变性剂和酸性pH对CF的影响,如果需要,使用双态假设对数据进行分析。结果:GdnHCl使该蛋白的二级和三级结构完全丧失。在4 M GdnHCl下观察到所有酶活性的丧失。CF对9 M尿素和50%乙醇具有结构抗性。不同变性剂处理的CF和MFF在最大排放量、丙烯酰胺猝灭、变性转变和酶活性方面存在显著差异。CF在酸性pH下的稳定性优于MFF。结论:CF在结构上比MFF更耐化学和酸变性。
Structural stability of commercial ficin under different denaturing conditions
Aim: To study the conformational stability of commercial ficin (CF) in the presence of guanidine hydrochloride (GdnHCl), urea, ethanol or at acidic pH and compare it with that reported for the major ficin fraction (MFF) obtained by purification of CF. Methods: Far-UV and near-UV CD spectral signals, intrinsic fluorescence, acrylamide quenching and enzymatic activity were used to study the effects of chemical denaturants and acidic pH on CF. The data were analyzed using two-state hypothesis, if required. Results: GdnHCl produced complete loss of secondary and tertiary structures of the protein. Loss of all enzymatic activity was observed at 4 M GdnHCl. CF showed structural resistance against 9 M urea and 50 % ethanol. Significant differences in emission maximum, acrylamide quenching, denaturation transition and enzymatic activity were noted between CF and MFF treated with different denaturants. CF showed greater stability at acidic pH than MFF. Conclusion: We conclude that CF is more structurally resistant than MFF against chemical and acid denaturations.
期刊介绍:
Turkish Journal of Biochemistry (TJB), official journal of Turkish Biochemical Society, is issued electronically every 2 months. The main aim of the journal is to support the research and publishing culture by ensuring that every published manuscript has an added value and thus providing international acceptance of the “readability” of the manuscripts published in the journal.