μNS and σNS belong to non-structctural proteins in avian reovirus. It has been reported that they are an important roles in replication of geneome or packaging of avian virion and are essential to consist of viroplasm. In avian reovirus infected cell, μNS is able to recruit proteins and makes up the viroplasm. σNS binds to single stranded nucleotides and is led into the viroplasm. In this study, we attempted to study structures and characters of these proteins in order to understand the viroplasm. First, we used E. coli expressed system to acquire large protein. Size exclusion chromatography proved that σNS forms heterooligomer with single stranded nucleotides and homooligomer made up by 2-3 units. Trp325 and Trp349 in σNS were assumed to affect ssDNA binding activeity by intrinsic fluorescence quenching assay. In addition, the results indicated that μNS possesses protease activity that enabled the protein to hydrolyze gelatin. The secondary structure of σNS shows mixture of α-helix and β-strand, with small changes induced by ssDNA and is influenced by low- pH value and high temperature. μNS likes also an α/ β secondary structure protein. In aspect of crystallization, we acquired at least three crystal growth conditions of σNS. Our results might be useful to realize the ARV viroplasm that is significantly relation with μNS and σNS in biological structure.

μNS 和σNS二個屬於家禽里奧病毒非結構性蛋白質。在很多文獻指出這二個蛋白質在家禽里奧病毒的基因體上的複製或是病毒顆粒的組裝上扮演著重要的角色。同時，也是病毒形成包涵體不可缺少的分子。μNS 有能力去募集組裝病毒顆粒的蛋白質和構成包涵體。而σNS具有單股核苷酸結合的活性，並將單股的單股核苷酸帶入包涵體中。在這個硏究中，我們為了更了解包涵體，因此針對與包涵體相關的μNS 和σNS在結構性和特性上進行硏究。首先，我們以大腸桿菌表現蛋白質系統取得大量的蛋白質。以體積排除層析法証明σNS與單股核苷酸形成異源性的聚合物，而σNS也會由二到三個σNS形成同源性的聚合物。在內源性的螢光相消實驗中，推估σNS中胺基酸序列的325和349色胺酸與單股核苷酸結合有明顯的關係。此外，μNS被証明像蛋白酶一樣可以水解明膠。在蛋白質的二級結構上，σNS呈現出α-螺旋和β-摺板混合的結構。當配位體結合或環境改變時，σNS的二級結構都會受影響。而μNS的二級結構也呈現出α-螺旋和β-摺板混合。最後，在蛋白質結晶方面，我們也獲得至少三個σNS結晶的可能條件。因此，我們研究的結果可能有助於更了解家禽里奧病毒病包涵體的結構特徵。

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