Large molecule bioconjugation

Bioconjugates made simpler

Large molecules, such as antibodies, peptides and related structures, represent a promising class of biomolecules, which are being used as efficient biomolecular tools, forming the basis of highly effective therapeutics. In 2017, one fourth of all drugs on the market were protein-based therapeutics treating chronic diseases such as cancer, diabetes, autoimmune diseases, rare genetic diseases, and others.

CF Plus Chemicals offers first-in-class, complementary hypervalent-iodine based bioconjugation technologies which allow for a straightforward modification of antibodies, peptides and other protein structures to uncover their full potential, improve their biological activity and increase their therapeutic index. We have been in particular devoted to apply our unique technologies to advance the development of Antibody Drug Conjugates, antibodies conjugated to toxic substances, which is a rapidly growing class of targeted biotherapeutics.

The novel technology has been demonstrated to conjugate small functional groups (up to 1000 Da) specifically to selected amino acids depending on the choice of protocol. In contrast to the conventional maleimide-based technology, our technology offers a highly stable peptide/antibody conjugation strategy which enables to control the overall amount of payload and lead to design of a safer next generation ADCs for immunooncology. Furthermore, our technology allows not only to conjugate various biorthogonal functional groups to large proteins in a site selective manner but it can be equally used to selectively install biorthogonal handles to existing natural product-based toxins. Our technology therefore constitutes a one-stop-shop technology which allows both bioconjugation of proteins as well as ample possibilities for optimization of warhead attachment strategy, thus streamlining the ADC discovery process on both key sides.

Benefits of our technology

Facilitates a controlled site-specific conjugation

Straightforward application leading to a cost-effective, high yielding conjugation

Improved stability in comparison to maleimide conjugation

Discovered, validated and patented at ETH Zurich

Thiol CF LINK™ Bioconjugation

Proteins containing solvent accessible free cysteine residues undergo a controlled, site-specific thiol bioconjugation with Togni-CF₂F₂R reagents without interference of other nucleophilic groups such as lysines. The S-bound conjugates are formed irreversibly and due to a unique ligation chemistry, they cannot undergo thiol exchange which is observed for conventional Michael acceptors, such as maleimides.

Advantages of our technology

Facilitates a controlled site-specific conjugation

Improved stability in comparison to maleimide conjugation

Tryptophan CF LINK™ Bioconjugation

Second generation of Togni reagents bearing the RCF₂CF₂ residues are very easily reduced by sodium ascorbate to generate highly reactive RCF₂CF₂• fluoroalkyl radicals. When generated in the presence of a protein that contains a solvent accessible tryptophan residue, the protein undergoes a highly site-selective tryptophan bioconjugation even in the presence of other aromatic amino acids.

CF LINK™ technology can be used to introduce a small, β-substituted fluoroalkyl group onto a solvent accessible tryptophan residue of a protein. Depending on the nature of the attached β-substituted fluoroalkyl, various protein modifications can be realized:

attachment of toxic/radioactive payloads via click chemistry
attachment of fluorescent dyes
attachment of stabilizing groups
attachment of other small molecules
protein immobilisation via click chemistry

Advantages of our technology

Unique tryptophan-selective bioconjugation

Complementary bioconjugation technology

Transition-metal free bioconjugation

CF LINK™ surface mapping of proteins

Togni reagents, which belong to the class of hypervalent iodine reagents, are extremely quickly (seconds) reduced by sodium ascorbate to generate highly reactive fluoroalkyl radicals. These in-situ generated fluoroalkyl radicals quickly react with the aromatic, solvent exposed amino acids present in the protein backbone, causing their rapid fluoroalkylation. Finally, proteolytic digestion and MS-based proteomics reveal which aromatic amino acids are solvent exposed (and thus undergoing fluoroalkylation) and which are solvent inaccessible (and thus immune to fluoroalkylation), either as a consequence of the protein's native structure or due to a binding of a substrate.

CF LINK™ technology can be used to map a protein surface, map the epitope, characterize proteins, probe protein-protein interactions, etc.