Purification and characterization of two cysteine proteinase inhibitors from silkworm, Bombyx mori
Purification and characterization of two cysteine proteinase inhibitors from silkworm, Bombyx mori
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家蚕两种半胱氨酸蛋白酶抑制剂的纯化和表征
DOI：
10.1016/j.bbrc.2018.08.100
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发表时间：
2018
影响因子：
3.1
通讯作者：
Yong Hou
中科院分区：
文献类型：
--
作者：
Huan Yang;Jianwei Li;Qing Liu;Ziyu Zhang;Jing Gong;Yong Hou
家蚕半胱氨酸蛋白酶抑制剂是一种选择性的小分子抑制剂，通过调节组织蛋白酶L样半胱氨酸蛋白酶的活性，从而影响家蚕的变态。在先前的研究中，在家蚕基因组中鉴定了两种半胱氨酸蛋白酶抑制剂BCPI和BmCPI。为了表征这些抑制剂，我们在大肠杆菌中表达并纯化了它们，并分析了它们的结构和体外抑制活性。两种抑制剂均表现出较强的耐高温性。它们的圆二色性光谱表明，它们的二级结构可以通过温度的逐渐降低而恢复。与BCPI相比，BmCPI对组织蛋白酶L的抑制活性较弱。当其C-末端被截短时，BCPI活性显著降低，而当BCPI的C-末端尾部连接到BmCPI时，BmCPI活性显著增加。此外，如果R31突变为A31，则BCPI的抑制活性强烈降低。本研究对两种家蚕半胱氨酸蛋白酶抑制剂进行了表征，为进一步了解家蚕半胱氨酸蛋白酶及其抑制剂之间的相互作用机制奠定了基础。
Cysteine proteinase inhibitors from silkworm are selective inhibitors with low molecular weight and regulate cathepsin L-like cysteine proteinase activity, thus, affecting silkworm metamorphosis. In a previous study, two cysteine proteinase inhibitors, BCPI and BmCPI, were identified in the silkworm genome. To characterize these inhibitors, we expressed and purified them in anEscherichia colisystem and analyzed their structure and inhibitory activityin vitro. Both inhibitors showed strong tolerance to high temperature. Their CD spectra revealed that their secondary structures could be recovered by a gradual decrease in temperature. Compared to BCPI, BmCPI exhibited weak inhibitory activity toward cathepsin L. BCPI activity was significantly decreased when its C-terminus was truncated, whereas BmCPI activity increased considerably when the C-terminus tail of BCPI was attached to BmCPI. Additionally, the inhibitory activity of BCPI was strongly reduced if R31 was mutated to A31. In summary, two cysteine proteinase inhibitors from silkworm were characterized in the present study, which facilitates an understanding of the interaction mechanism between cysteine proteinase and its inhibitors in the silkworm.