Thermostable properties of the equine infectious anemia virus nucleocapsid protein NCp11
Thermostable properties of the equine infectious anemia virus nucleocapsid protein NCp11
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马传染性贫血病毒核衣壳蛋白 NCp11 的热稳定性
DOI：
10.1016/j.bbrc.2019.01.137
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发表时间：
2019
影响因子：
3.1
通讯作者：
Wang Ying
中科院分区：
文献类型：
--
作者：
Wang Jinzhong;Wang Qinghua;Hao Shasha;Guo Chao;An Jing;Zhang Qingmiao;Liang Ruonan;Wang Ying
逆转录病毒核衣壳（NC）蛋白是多功能的核酸结合蛋白，在病毒复制周期的基本上每一个步骤中起关键作用。作为一种小的碱性蛋白，NC含有一个或两个高度保守的锌指结构域，每个锌指结构域具有不变的CCHC基序，两侧是碱性残基。本研究首次报道了马传染性贫血病毒（EIAV）NCp 11的热稳定性。在100 °C孵育60 min后，约43%的纯化的NCp 11保持可溶性，并且热处理的NCp 11保持其与大肠杆菌RNA和EIAV包装信号序列结合的能力。在一个非常高的序列占有率，NCp 11抑制第一链cDNA合成催化的商业或纯化的EIAV逆转录酶，热处理的NCp 11仍然抑制第一链cDNA合成。我们还发现，蛋白质浓度在0.1至0.9 μg/μl的范围内，对NCp 11的热稳定性没有显著影响。然而，NCp 11在酸性pH下更耐热。我们的发现突出了NC蛋白的一个新特征。深入了解NC的性质和功能将有助于开发有效合理的逆转录病毒治疗策略。
Retroviral nucleocapsid (NC) proteins are multifunctional nucleic acid binding proteins, playing critical roles in essentially every step of the viral replication cycle. As a small, basic protein, NC contains one or two highly conserved zinc-finger domains, each having an invariant CCHC motif, flanked by basic residues. In this study, we report for the first time, to our knowledge, the thermostable property of equine infectious anemia virus (EIAV) NCp11. About 43% of purified NCp11 remained soluble after incubation at 100 °C for 60 min, and heat-treated NCp11 maintained its abilities to bind to theE. coliRNA and the EIAV packaging signal sequence. At a very high degree of sequence occupancy, NCp11 inhibited first-strand cDNA synthesis catalyzed by either a commercial or the purified EIAV reverse transcriptase, and heat-treated NCp11 still inhibited the first-strand cDNA synthesis. We also found that protein concentrations, at a range from 0.1 to 0.9 μg/μl, have not affected the NCp11 thermostability significantly. However, NCp11 at acidic pH was more thermostable. Our findings highlight a new feature of the NC protein. Detailed understanding of NC's properties and functions will facilitate the development of effective and rational therapeutic strategies against retroviruses.