Covalent Attachment of Functional Proteins to Microfiber Surfaces via a General Strategy for Site-Selective Tetrazine Ligation.

Surface modification of materials with proteins has various biological applications, and hence the methodology for surface modification needs to accommodate a wide range of proteins that differ in structure, size, and function. Presented here is a methodology that uses the Affinity Bioorthogonal Chemistry (ABC) tag, 3-(2-pyridyl)-6-methyltetrazine (PyTz), for the site-selective modification and purification of proteins and subsequent attachment of the protein to -cyclooctene (TCO)-functionalized hydrogel microfibers. This method of surface modification is shown to maintain the functionality of the protein after conjugation with proteins of varying size and functionalities, namely, HaloTag, NanoLuc luciferase (NanoLuc), and fibronectin type III domains 9-10 (FNIII 9-10).

Mechanistic differences between linear spirocyclic dialkyldiazirine probes for photoaffinity labeling.

Dialkyldiazirines have emerged as a photo-reactive group of choice for interactome mapping in live cell experiments. Upon irradiation, 'linear' dialkyldiazirines produce dialkylcarbenes which are susceptible to both intramolecular reactions and unimolecular elimination processes, as well as diazoalkanes, which also participate in intermolecular labeling. Cyclobutylidene has a nonclassical bonding structure and is stable enough to be captured in bimolecular reactions.