Tag Archives: immunodiagnostics

Production of recombinant SARS-COV-2 proteins and diphtheria toxoid CRM197-based fusion

O. I. Krynina1, S. I. Romaniuk1, O. B. Gorbatiuk1,2,
O. H. Korchynskyi1,3,4, А. V. Rebriiev1, Ya. S. Kulyk1,
Ye. O. Kozadaieva1, A. A. Siromolot1,5, M. M. Guzyk1,
D. V. Kolybo1*, S. V. Komisarenko1

1Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
2State Institute of Genetic and Regenerative Medicine, National Academy of Medical Sciences of Ukraine, Kyiv;
3Centre for Innovative Research in Medical and Natural Sciences, Faculty of Medicine, University of Rzeszow, Rzeszow, Poland;
4S. Gzhytskyi National University of Veterinary Medicine and Biotechnologies, Lviv, Ukraine;
5ESC “Institute of Biology and Medicine”, Taras Shevchenko National University of Kyiv, Ukraine;
*e-mail: kolibo@biochem.kiev.ua

Received: 10 October 2021; Accepted: 12 November 2021

The quickly emerged global COVID-19 pandemic raised a desperate need in the development of protecting vaccines targeting this disease. Therefore, a generation of effective producers of recombinant SARS-CoV-2 proteins became an urgent task. Its resolving contributes to the study of functional SARS-CoV-2 properties, as well as will allow developing the domestic COVID-19 vaccine in Ukraine, thus playing an important strategic role in tackling the pandemics. The aim of the study was to generate prokaryotic and eukaryotic producers of recombinant SARS-CoV-2 proteins and to isolate nucleocapsid (N) protein, receptor-binding domain (RBD) of spike (S) protein, as well as RBD fused to the carrier – diphtheria toxoid CRM197. For this purpose, appropriate genetic constructs, in particular, replication deficient recombinant AdvC5-based adenoviral vectors expressing the SARS-CoV-2 proteins and CRM197-fused conjugate were created through methods of molecular biology and genetic engineering. Restriction analysis and/or DNA sequencing confirmed that we created the correct constructs. Immobilized metal affinity chromatography was used to purify the recombinant proteins. Compliance of their properties was confirmed by the results from polyacrylamide gel electrophoresis, Western blotting, immunoenzymatic assay and MALDI-TOF mass spectrometry. As a result, we generated E. coli Rosetta (DE3) bacterial strain and HEK293 cell line producing recombinant SARS-CoV-2 proteins and CRM197-based fusion. In addition, pure N protein, RBD of S protein and RBD-CRM197 fusion protein were isolated. The obtained recombinant SARS-CoV-2 proteins can be used to study immunogenic and antigenic properties of the SARS-CoV-2 proteins. Cells producing recombinant SARS-CoV-2 proteins and RBD-CRM197 fusion protein are able to provide cheap and safe synthesis of the antigenic substances for domestic development and production of immunodiagnostics for COVID-19 and COVID-19 vaccines in Ukraine.

Novel monoclonal antibody to fibrin(ogen) αC-region for detection of the earliest forms of soluble fibrin

N. E. Lugovska1, I. M. Kolesnikova1, Ye. M. Stohnii1, V. O. Chernyshenko1*,
A. V. Rebriev1, O. P. Kostiuchenko1, G .K. Gogolinska1, N. A. Dziubliuk2,
L. D. Varbanets2, T. M. Platonova1, S. V. Komisarenko1

1Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
2Zabolotny Institute of Microbiology and Virology,National Academy of Sciences of Ukraine, Kyiv;
*e-mail: bio.cherv@gmail.com

Received: 08 May 2020; Accepted: 30 June 2020

Obtaining new monoclonal antibodies (mAbs) towards fibrin(ogen) and its fragments is an important task for studying mechanisms of blood clot formation, searching for novel antithrombotic agents and developing immunodiagnostics. The aim of the present work was to create and characterize a new mAb towards the fibrin(ogen) αС-region. We surmise that having a specific mAb towards this flexible part of the molecule will allow us to study the role of the αС-region in fibrin polymerization and also to develop an approach for detecting the earliest forms of soluble fibrin by sandwich ELISA. Using hybridoma technology we оbtained mAb 1-5A to the αC-region of fibrinogen.. It was characterized using several variations of ELISA and Western blot. Application of specific proteases together with MALDI-TOF analysis allowed us to localize its epitope that is located in fragment 537-595 of the Aα-chain of fibrin(ogen). МAb 1-5A can be used as a detecting tag-antibody in sandwich ELISA for the quantification of the earliest forms of soluble fibrin which are uncleaved by plasmin and preserved C-terminal portions of αC-regions. These earliest forms of soluble fibrin are direct evidence of blood coagulation system activation, thrombin generation and the danger of intravascular thrombus formation. Their determination will provide additional, more accurate information about the state of the blood coagulation system and the risk of blood clotting, which is very important for the timely and correct selection of adequate antithrombotic therapy. MAb 1-5A effectively binds the αC-containing molecules of fibrinogen and fibrin in blood plasma. It also can be used for studying protein-protein and protein-cellular interactions of the αC-regions of fibrin(ogen).