Abstract:Abstract: Bacterioferritin (BFR) from Escherichia coli is composed of 24 subunits that assemble into a large spherical cage with octahedral symmetry, with one heme molecule located at each C2 symmetry interface. To study the effect of heme on the protein stability and self-assembly, heme molecules were removed through site-directed mutagenesis. The mutant protein M52A was expressed, purified and characterized using size exclusion chromatography, transmission electron microscopy, UV-Vis spectroscopy and circular dichroism. Results indicated that although little effect was observed on the self-assembly of protein structure, removal of heme showed great impact on its thermostability. The melting temperature (Tm) of mutant M52A was 54.3 ℃, which was much lower than that of its wild type 69.9 ℃. Interestingly, when mutant M52A was incubated with hemin chloride, the melting temperature was restored to 67.7 ℃. Hence, heme molecules located at C2 symmetry interfaces in the bacterioferritin has a regulatory effect and plays a key role in the protein thermostability.
引用本文:
张 瑜, 周金花, 周亦琛, 李 迅, 王 飞. 血红素对大肠杆菌铁蛋白稳定性及自组装的影响[J]. 生命科学研究, 2017, 21(4): 283-288.
ZHANG Yu, ZHOU Jin-hua, ZHOU Yi-chen, LI Xun, WANG Fei. Effect of Heme on the Stability and Self-assembly of Escherichia coli Bacterioferritin. Life Science Research, 2017, 21(4): 283-288.