NEC Corporation and NEC Solution Innovators have announced the successful development of artificial DNA aptamers using SELEX technology that bind to the novel coronavirus (SARS-CoV-2). This breakthrough stems from the NEC Group’s efforts to promote spatial monitoring business using aptamers, including the development of new bio-sensing systems, such as measuring equipment that can monitor spaces where various viruses, including SARS-CoV-2 and influenza viruses, are present.
Overview of Aptamers
SARS-CoV-2 enters into human cells when the spike protein, Receptor-Binding Domain, on the surface of the virus binds to the ACE2 receptors on the surface of human cells.
The aptamer developed by NEC Solution Innovators targets RBD, which is the key to infection, then traps the virus by recognizing the three-dimensional structure of the RBD and binding very strongly to it, a dissociation constant indicating the strength of the binding between molecules is less than 1nM). This aptamer uses a new modified base called Base appended Base, Patent No. 6763551, which was developed by NEC Solution Innovators and Gunma University from 2014-2017 supported by a grant for “Adaptable and Seamless Technology Transfer Program through Target-driven R&D” (A-STEP) from the Japan Science and Technology Agency (JST).
Three variants of SARS-CoV-2, including the original strain (WK521 Wuhan strain) and two mutant strains (TY7-501 Brazilian and QK002 UK strains) are being studied by academic laboratories in collaboration with the NEC Group. The binding assessment tests with aptamers were conducted in a bio-safety level 3 (*6, BSL3) laboratory, which is allowed to handle SARS-CoV-2.
Binding assessment tests were conducted using the Direct ELAA method (*7), in which viruses were adsorbed onto plates and detected with enzyme-labeled aptamers. As a result, a strong binding of aptamers to SARS-CoV-2 was observed in all three strains.
The NEC group is developing a measuring device that enables spatial monitoring of SARS-CoV-2 by combining MSSs , Membrane-type Surface Stress Sensor and an aptamer that binds to SARS-CoV-2. This measuring device is designed to be used in spaces where people gather and spend time in close proximity, such as public facilities, restaurants, lodging facilities, event venues and offices. In fiscal 2021, NEC expects to provide a prototype of a fixed-type spatial monitoring measuring device for companies, universities and other research institutions that perform virus measurement and other measures. In addition, in fiscal 2022, NEC aims to provide a bio-sensing system that can be used for space monitoring and as an embedded device for equipment such as air conditioners.