The ongoing pneumonia outbreak in the city of Wuhan is caused by a newly identified coronavirus 2019-nCoV, named by the World Health Organization on January 12nd, 2020. This new virus belongs to the Betacoronavirus Genus, which also includes SARS CoV (2003) and MERS CoV (2012). The sequence similarity between 2019-nCoV and MERS-CoV is 40%, while that between 2019-nCoV and SARS-CoV is 70%.
What are Coronaviruses?
Coronaviruses are large, enveloped, positive-sense single- stranded RNA viruses. They have the largest genome among all RNA viruses, typically ranging from 27 to 32kb. The molecular weight is usually (5.5-6.1) x 106.
What are the Antigens of Coronavirus?
The genome of coronavirus encodes the spike protein, the envelope protein, the membrane protein, and the nucleocapsid protein.The spike protein is the most important surface protein. The main functions for the Spike protein is summarized below:
(1) The spike protein mediates receptor binding and membrane fusion. (2) The spike protein defines the range of the hosts and specificity of the virus. (3) The spike protein can be transmitted between different hosts through gene recombination or mutation of the receptor binding domain (RBD), leading to a higher mortality rate. (4) The spike protein is the main component to bind with the neutralizing antibody. (5) The spike protein is the key target for vaccine design.
Structure of the Spike Protein
The spike protein is a large type I transmembrane protein containing two subunits, S1 and S2. S1 mainly contains a receptor binding domain (RBD), which is responsible for recognizing the cell surface receptor. S2 contains basic elements needed for the membrane fusion. It’s been reported that 2019-nCoV can infect the human respiratory epithelial cells through interaction with the human ACE2 receptor.
Structure of the Nucleocapsid Protein
Nucleocapsid is an unit of viral structure, consisting of a capsid with the enclosed nucleic acid; it is generally inside the cytoplasm. The nucleocapsid may correspond to a naked core or be surrounded by a membranous envelope depending on the virus.
The nucleocapsid protein (N-protein) is the most abundant protein in coronavirus. The N-protein is a highly immunogenic phosphoprotein, and well conserved and is often used as a marker in diagnostic assays.
Dr Jayaraman D. Lead Scientist, leading CRO company
I have been working with a team from KRISHGEN on an assay development and customization before giving us. The project was complicated and needed technical expertise in immunology. I was very pleased with their technical competence and also mastering immunology and delivering a tough project to us on time. Their rigor, punctuality and expertise have been a recipe for the high standards, I would expect for such project from them. Kudos, Krishgen Team!!!
Mr Ramesh Sravanan, VP-Supply Chain
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consistently is the key to their success.
Dr Keith Stevens, visiting Scientist, Norfolk University, UK
To have a company understand science and work with them, is a pleasure. Krishgen
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Mellisa Karlowski, Lead Researcher, east coast US CRO
The company is good on understanding its customers, is transparent and
speaks science. This makes it easier for us to work with them.