Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


New technology CF LINK for protein bioconjugation and structural proteomics


The cooperation of two Prague research institutes - Institute of Organic Chemistry and Biochemistry and Institute of Microbiology of the Czech Academy of Sciences and the Brno based start-up CF Plus Chemicals, a spin-off of ETH Zurich, has brought a new technology called CF LINK for site-selective bioconjugation of proteins and also their structural characterization. The recently published, patent-pending technology, allows to selectively prepare protein conjugates via their tryptophan residues and perform posttranslational modification of aromatic amino acids. Furthermore, it can also be used as a tool for the mapping of protein surfaces and studies of protein-protein interactions.

The company CF Plus Chemicals, an ETH Zurich spin-off founded in 2014, is based on almost ten years of cooperation of the group of Dr. Petr Beier at the Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences (IOCB Prague) and Dr. Václav Matoušek, a Ph.D. alumnus of Prof. Dr. Antonio Togni at ETH Zurich.

New technology CF LINK for protein bioconjugation and structural proteomics

Credit: IOCB Prague (Source:

Reagents based on cyclic hypervalent iodine-perfluoroalkyl compounds, nowadays also termed as the Togni reagents, have become widely used and popular tools in organic synthesis, especially in medicinal chemistry for preparation of new fluorinated drug candidates, in-line with the growing demand for fluorinated scaffolds in drug design.

While in the early 1990s fluorinated molecules accounted for 5% of the total number of approved drugs, now it is 15% and roughly 30% for newly approved therapeutics.

This family of chemical compounds was subsequently expanded in 2013 in collaboration of ETH Zurich and Dr. Petr Beier from IOCB to a new generation of patented Togni reagents that carry a more complex RCF2CF2 group instead of a simple CF3 group.[1]

The new family of these chemicals shares not only the rich reactivity of the first generation of Togni reagents, but also brings an extra dimension due to the virtually unlimited structural variability of the β-substituted tetrafluoroethyl group which they are able to transfer to a variety of substrates relevant to medical chemistry of small molecules.

In 2017, the application potential of the second generation of Togni reagents was extended to proteins.[2 ] Their high affinity towards the thiol group allows to perform selective bioconjugation through cysteines to form stable conjugates which, unlike maleimide conjugates, are not subject to slow deconjugation and thiol exchange.

The present invention[3,4] builds on the previous knowledge of the radical nature of Togni reagent-mediated reactions. In the SME Instrument Horizon 2020 project, supported by the City of Brno and in cooperation with IOCB and Dr. Petr Novák from the Institute of Microbiology of the Czech Academy of Sciences (IMIC), it was showcased that Togni reagents, when mixed with sodium ascorbate, a cheap, non-toxic and biocompatible reducing agent, immediately generate ß-substituted tetrafluoroethyl radicals that selectively attach to sterically accessible tryptophan residues of the protein under transition metal-free conditions.

Once azidofluoroalkyl groups are attached to the protein, various functional groups, such as fluorescent dyes, radionuclides or ADC-toxins for targeted oncotherapy can be subsequently linked via click reaction to afford the corresponding protein conjugates.

The disclosed tryptophan-selective bioconjugation method does not disrupt protein disulfide bridges and offers an alternative solution where conventional cysteine conjugation is not possible, for example due to an undesirable disulfide scrambling.

This bioconjugation method can also be extended to other aromatic amino acids and hence to proteins lacking tryptophan. Thus, it was possible to successfully modify human recombinant insulin and attach up to 7 modifications to its aromatic amino acids, demonstrating the potential for post-translational modification of proteins.

The extremely rapid nature of this reaction that targets solvent-accessible aromatic amino acids makes it a convenient tool for mapping protein surfaces and studying protein-protein interactions. Using the example of human carbon anhydrase, it has been demonstrated that the results of surface mapping are in excellent agreement with its published native structure.

The second generation of Togni-CF2CF2R reagents is protected by a worldwide patent owned by ETH Zurich and IOCB and are exclusively licensed by CF Plus Chemicals.

The new CF LINK ascorbate technology, a subject of another patent application, further strengthens the intellectual property protection and forms a technology package which is currently offered to licensing to business partners for bioconjugation of diagnostically and therapeutically relevant proteins/antibodies, preparation the corresponding immunoconjugates with fluorescence dyes, radionuclides or ADC-toxins, post-translational protein modification, structural proteomics and study of protein-protein interactions.

Prof. Dr. Martin Fusek, CEO of IOCB Tech: „The basis of successful commercial outcomes from basic research results is excellent scientific work. This is an important result that is not only useful as a tool for basic research but also as a means for the development of new protein-based drugs. The uniqueness, which should rather be the rule, is that the project was created by the cooperation of two academic and one commercial subject. I am very glad that we could have been part of the process, albeit small."

Dr. Petr Beier, Head of a research group at IOCB Prague: "I am glad that we have been able to develop a successful cross-disciplinary collaboration of organic synthesis and biochemistry. It turns out that the specific properties of fluorinated compounds can be utilized not only traditionally in the medical chemistry of small molecules, but as recently showcased also for bioconjugation of proteins and studies of their structure. I believe that in the future we will be able to identify other attractive uses of Togni reagents in biochemistry."

Dr. Petr Novák, Head of a research group at IMIC: „Thanks to Togni reagents we have been able to introduce a fluorinated probe into the protein structure in an aqueous environment in a matter of few seconds. We are now able to use this technology to selectively tag proteins for clinical diagnostics or use to it to identify the interaction interface of proteins with their ligands.

Dr. Václav Matoušek, CEO of CF Plus Chemicals: "I am excited to see that the reactivity of Togni reagents could be extended to aromatic amino acids and aromates in general, thus opening a plethora of potential applications, especially in protein science and protein-based therapeutics. We are now actively looking for established industrial partners who could apply our technology to solve their challenges."



1) V. Matoušek, J. Václavík, P. Hájek, J. Charpentier, Z. E. Blastik, E. Pietrasiak, A. Budinská, A. Togni, P. Beier, Chem. Eur. J. 2016, 22, 417-424.
2) J. Václavík, R. Zschoche, I. Klimánková, V. Matoušek, P. Beier, D. Hilvert, A. Togni, Chem. Eur. J. 2017, 23, 6490-6494.
3) K. Rahimidashaghoul, I. Klimánková, M. Hubálek, M. Korecký, M. Chvojka, D. Pokorný, V. Matoušek, L. Fojtík, D. Kavan, Z. Kukačka, P. Novák, P. Beier, Chem. Eur. J., 2019, accepted manuscript. doi:10.1002/chem.201902944, pending patent EP 19172756.9.
4) pending patent EP 2982672 A1, granted US patent 10,040,812 B2

About CF Plus Chemicals: CF Plus Chemicals ( is a Brno, Czechia-based ETH Zurich spin-off founded in 2014 focusing on life science applications of fluoroorganic chemistry both in the field of small molecules in medical chemistry and in the field of large molecules, especially of proteins.

About IOCB Prague: The Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences ( is a leading internationally recognized scientific institution whose primary mission is the pursuit of basic research in chemical biology and medicinal chemistry, organic and materials chemistry, chemistry of natural substances, biochemistry and molecular biology, physical chemistry, theoretical chemistry, and analytical chemistry. An integral part of the IOCB Prague's mission is the implementation of the results of basic research in practice. Emphasis on interdisciplinary research gives rise to a wide range of applications in medicine, pharmacy, and other fields.

About IMIC: Institute of Microbiology of the Czech Academy of Sciences ( represents the largest scientific body in the Czech Republic focused on physiology, cell and molecular biology of various microorganisms. The main research areas include genetics, biochemistry, physiology and ecology of bacteria, yeasts and filamentous fungi, microscopic algae and immunology. IMIC has also a unique position in multidisciplinary research mainly due to scientific excellence in already existing infrastructure modules. Namely, next-generation sequencing, mass spectrometry, nuclear magnetic resonance, electron microscopy, and germ-free animal rearing facility are developing with respect to basic research questions and to their prospective practical exploitation in medicine and industry.

Media Contact

Dr. Václav Matoušek


Dr. Václav Matoušek | EurekAlert!
Further information:

Further reports about: Biochemistry ETH ETH Zurich amino acids basic research proteins small molecules

More articles from Life Sciences:

nachricht Biophysicists reveal how optogenetic tool works
29.05.2020 | Moscow Institute of Physics and Technology

nachricht Mapping immune cells in brain tumors
29.05.2020 | University of Zurich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Biotechnology: Triggered by light, a novel way to switch on an enzyme

In living cells, enzymes drive biochemical metabolic processes enabling reactions to take place efficiently. It is this very ability which allows them to be used as catalysts in biotechnology, for example to create chemical products such as pharmaceutics. Researchers now identified an enzyme that, when illuminated with blue light, becomes catalytically active and initiates a reaction that was previously unknown in enzymatics. The study was published in "Nature Communications".

Enzymes: they are the central drivers for biochemical metabolic processes in every living cell, enabling reactions to take place efficiently. It is this very...

Im Focus: New double-contrast technique picks up small tumors on MRI

Early detection of tumors is extremely important in treating cancer. A new technique developed by researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from normal tissue. The work is published May 25 in the journal Nature Nanotechnology.

researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from...

Im Focus: I-call - When microimplants communicate with each other / Innovation driver digitization - "Smart Health“

Microelectronics as a key technology enables numerous innovations in the field of intelligent medical technology. The Fraunhofer Institute for Biomedical Engineering IBMT coordinates the BMBF cooperative project "I-call" realizing the first electronic system for ultrasound-based, safe and interference-resistant data transmission between implants in the human body.

When microelectronic systems are used for medical applications, they have to meet high requirements in terms of biocompatibility, reliability, energy...

Im Focus: When predictions of theoretical chemists become reality

Thomas Heine, Professor of Theoretical Chemistry at TU Dresden, together with his team, first predicted a topological 2D polymer in 2019. Only one year later, an international team led by Italian researchers was able to synthesize these materials and experimentally prove their topological properties. For the renowned journal Nature Materials, this was the occasion to invite Thomas Heine to a News and Views article, which was published this week. Under the title "Making 2D Topological Polymers a reality" Prof. Heine describes how his theory became a reality.

Ultrathin materials are extremely interesting as building blocks for next generation nano electronic devices, as it is much easier to make circuits and other...

Im Focus: Rolling into the deep

Scientists took a leukocyte as the blueprint and developed a microrobot that has the size, shape and moving capabilities of a white blood cell. Simulating a blood vessel in a laboratory setting, they succeeded in magnetically navigating the ball-shaped microroller through this dynamic and dense environment. The drug-delivery vehicle withstood the simulated blood flow, pushing the developments in targeted drug delivery a step further: inside the body, there is no better access route to all tissues and organs than the circulatory system. A robot that could actually travel through this finely woven web would revolutionize the minimally-invasive treatment of illnesses.

A team of scientists from the Max Planck Institute for Intelligent Systems (MPI-IS) in Stuttgart invented a tiny microrobot that resembles a white blood cell...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

Aachen Machine Tool Colloquium AWK'21 will take place on June 10 and 11, 2021

07.04.2020 | Event News

International Coral Reef Symposium in Bremen Postponed by a Year

06.04.2020 | Event News

Latest News

Black nitrogen: Bayreuth researchers discover new high-pressure material and solve a puzzle of the periodic table

29.05.2020 | Materials Sciences

Argonne researchers create active material out of microscopic spinning particles

29.05.2020 | Materials Sciences

Smart windows that self-illuminate on rainy days

29.05.2020 | Power and Electrical Engineering

Science & Research
Overview of more VideoLinks >>>