【COVID-19新型冠狀病毒肺炎】新冠病毒S1蛋白、N蛋白、人ACE2蛋白，人源抗體、單域抗體

【新型冠狀病毒肺炎（COVID-19）】新冠病毒S1蛋白、N蛋白、人ACE2蛋白，人源抗體、單域抗體

冠狀病毒結構圖示

自2019年12月第一例新型冠狀病毒肺炎（COVID-19）報導以來，至2020年4月已造成全球超過百萬人的感染^[1]。與2003年非典型性肺炎（SARS）類似，COVID-19的致病病毒是SARS-COV-2，也是一種典型的RNA病毒，與SARS-COV同屬β冠狀病毒屬（Betacoronavirus）^[2]。SARS-COV-2病毒粒子外為一層脂肪膜，膜內為病毒核衣殼蛋白N蛋白（Nucleocapsid,N）；膜表面有三種糖蛋白：S蛋白（Spike protein）、E蛋白（Envelope protein）和M蛋白（Membrane protein）^[4]。其中的S蛋白決定了病毒的宿主範圍和特異性^[5]。目前COVID-19尚無特效療法^[6]。專注於治療和診斷性單克隆抗體技術的發展，為了幫助人們深入瞭解SARS-COV-2的特點和致病機制，研發針對性的檢測方法和治療方法，全系列新冠病毒相關蛋白和抗體試劑，包括新冠病毒的S1蛋白、N蛋白、人ACE2蛋白，以及針對這幾種蛋白的人源抗體、單域抗體等。這些蛋白使用真核表達體系，使用ELISA、FACS等多種方法進行活性驗證；而多組可以配對的S1單抗，更是為病毒的檢測提供了豐富選擇。

Since the first case of the SARS-COV-2 pneumonia (COVID-19) was reported in December 2019, more than one million people have been infected worldwide by April 2020^[1]. Similar to SARS in 2003, the pathogenic virus of COVID-19 is SARS-COV-2, also a typical RNA virus. It belongs to Betacoronavirus, the same as SARS-COV^[2].The SARS-COV-2 virus particle is covered with a lipid membrane layer, and this membrane contains N virus protein (Nucelocapsid, N).There are three types of glycoproteins on the membrane surface: S protein (Spike protein), E protein (Envelope protein) and M protein (Membrane protein)^[4]. The S protein determines the host coverage and specificity of the virus^[5].There is no specific treatment for COVID-19 at present.^[6] Focused on the development of therapeutic and diagnostic monoclonal antibody technologies, Sanyou Bio is dedicated to help researchers to understand the characteristics and pathogenic mechanisms of SARS-COV-2,and to develop detection and treatment methods.We have launched a full bundle of SARS-COV-2 proteins and antibodies, including the S1 protein, N protein, human ACE2 protein, as well as human antibodies and single-domain antibodies against these proteins. All of these proteins are expressed using eukaryotic expression system, and verified and validated using ELISA,comma after FACS and other activity test methods. Even more, we have discovered multiple sets of paired S1 monoclonal antibodies, which provides a powerful resource for virus detection.

重組蛋白

抗體

對照抗體

Fig.2 病毒膜表面糖蛋白S1與人ACE2蛋白的結合，是病毒感染人體細胞的基礎。使用ELISA方法，證明新冠病毒S1蛋白與人ACE2受體有優異的結合活性，親和力為1.07 nM。

Fig.3 阻斷S1蛋白和受體ACE2蛋白的結合，是當前進行抗新冠藥物研究的主要作用機制。抗S1-RBD人源抗體對SARS-COV-2病毒S1-RBD蛋白與受體ACE2結合展示出了良好的阻斷活性，阻斷活性為0.89 nM。

Fig.4 配對抗體是使用雙抗夾心法檢測抗原的關鍵材料^[7]。兩個抗S1-RBD人源單抗能同時與新冠S1-RBD蛋白的不同表位穩定結合，EC50值為0.23 nM。
參考文獻：

[1] WHO. COVID-19 cases and deaths[EB/OL]. https://who.sprinklr.com/.
[2] SHANG J, YE G, SHI K, et al. Structural basis of receptor recognition by SARS-CoV-2[J]. Nature, 2020.
[3] MACKAY I M, ARDEN K E. An Opportunistic Pathogen Afforded Ample Opportunities: Middle East Respiratory Syndrome Coronavirus[J]. Viruses, 2017,9(12).
[4] LAN J, GE J, YU J, et al. Structure of the SARS-CoV-2 spike receptor-binding domain bound to the ACE2 receptor[J]. Nature, 2020.
[5] WANG Q, ZHANG Y, WU L, et al. Structural and Functional Basis of SARS-CoV-2 Entry by Using Human ACE2[J]. Cell, 2020.
[6] AHN D G, SHIN H J, KIM M H, et al. Current Status of Epidemiology, Diagnosis, Therapeutics, and Vaccines for Novel Coronavirus Disease 2019 (COVID-19)[J]. J Microbiol Biotechnol, 2020,30(3): 313-324.
[7] KOHL T O, ASCOLI C A. Immunometric Double-Antibody Sandwich Enzyme-Linked Immunosorbent Assay[J]. Cold Spring Harb Protoc, 2017,2017(6): t93724.