Delivery of Antibody-Like Molecules, Monobodies, Capable of Binding with SARS-CoV-2 Virus Nucleocapsid Protein, into Target Cells.

Based on previous studies, two antibody-like molecules, monobodies, capable of high-affinity interaction with the SARS-CoV-2 nucleocapsid protein (dissociation constant of tens of nM) were selected. For delivery to target cells, genetically engineered constructs containing monobody and TAT peptide, placed either at the N- or C-terminus of the resulting polypeptide, were produced and expressed in E. coli. The construct with the highest affinity to the SARS-CoV-2 nucleocapsid protein was revealed with the use of thermophoresis technique. Cellular thermal shift assay demonstrated the ability of this construct to interact with the nucleocapsid protein within HEK293T cells transfected with the SARS-CoV-2 nucleocapsid protein fused to the mRuby3 fluorescent protein. Replacement of TAT peptide to S10 shuttle peptide, containing endosomolytic peptide, significantly improved the penetration of the construct into the target cells.

Application of non-chemical modification drug target discovery techniques in traditional Chinese medicine

Traditional Chinese medicine (TCM) is a science and cultural treasure of our country, with thousands of years of clinical experience in medication. TCM has significant advantages in prevention and treatment of complex diseases and chronic diseases, and has also demonstrated its advantages in prevention and treatment of corona virus disease 2019 (COVID-19) that is currently raging around the world, but due to unclear mechanism problem, the promotion and application of TCM have been seriously limited. Mechanism of Western medicine is clear, and it has mature drug target discovery technology, mainly including chemical modification technology and non-chemical modification technology. Due to the characteristics of multi-component, multi-target action of TCM, the application of chemical modification technology in TCM mechanism study has certain limitations. Thus, the principle, operation steps and application of non-chemically modified drug target technology such as cellular thermal shift assay, molecular docking, drug affinity responsive target stability, surface plasmon resonance are introduced in this paper. The potential advantages and disadvantages of such non-chemically modified drug target technologies are discussed in the study on mechanism of TCM, in order to explore a target discovery model of TCM target discovery, provide reference for elucidating the mechanism of TCM, and promote the modernization process of TCM. Copyright © 2022 Editorial Office of Chinese Traditional and Herbal Drugs. All rights reserved.