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 is the 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.
The Structure of 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.
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
The expertise and command on the logistics chain including the regulatory
guidelines from Krishgen is something we admire. As they often indicate, let us
do the supplies, and let your team focus on science … is really something the
company works on. Delivering consistently, with less than 1% error or delay
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
not only sells but understands what it sells in terms of the complex cutting
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.