Cashikar A G, Rao N M
Centre for Cellular and Molecular Biology, Hyderabad, India.
Biochim Biophys Acta. 1996 Aug 15;1296(1):76-84. doi: 10.1016/0167-4838(96)00055-6.
Quantitative equilibrium denaturation studies on oligomeric proteins have the potential to provide information on the role of subunit interactions in protein function and structure. We studied the equilibrium denaturation of red kidney bean purple acid phosphatase (KBPAP), a homodimer with a single disulfide bond between the two subunits, with an objective to understand the role of the intersubunit disulfide bond in KBPAP structure. Binding of 8-anilino-1-naphthalenesulfonic acid, enzymatic activity, size-exclusion chromatography, tryptophan fluorescence and circular dichroism studies revealed that the protein undergoes unfolding through at least three intermediates. Susceptibility of KBPAP for denaturation increases on reduction of the disulfide and aggregation was the predominant product of denaturation. In terms of stability, an intersubunit disulfide bond contributes to 25% of the overall stability of the dimer.
对寡聚蛋白进行定量平衡变性研究，有潜力提供关于亚基相互作用在蛋白质功能和结构中作用的信息。我们研究了红芸豆紫色酸性磷酸酶（KBPAP）的平衡变性，它是一种同型二聚体，两个亚基之间有一个二硫键，目的是了解亚基间二硫键在KBPAP结构中的作用。8-苯胺基-1-萘磺酸结合、酶活性、尺寸排阻色谱、色氨酸荧光和圆二色性研究表明，该蛋白至少通过三种中间体进行解折叠。二硫键还原后，KBPAP对变性的敏感性增加，聚集是变性的主要产物。就稳定性而言，亚基间二硫键对二聚体整体稳定性的贡献为25%。
