title: Conformationally Strainedtrans-Cyclooctene with Improved Stability and Excellent Reactivity in Tetrazine Ligation.
abstract: Computation has guided the design of conformationally-strained dioxolane-fusedtrans-cyclooctene (d-TCO) derivatives that display excellent reactivity in the tetrazine ligation. A water soluble derivative of 3,6-dipyridyl-s-tetrazine reacts with d-TCO with a second order ratek2366,000 (+/- 15,000) M-1s-1at 25 °C in pure water. Furthermore, d-TCO derivatives can be prepared easily, are accessed through diastereoselective synthesis, and are typically crystalline bench-stable solids that are stable in aqueous solution, blood serum, or in the presence of thiols in buffered solution. GFP with a genetically encoded tetrazine-containing amino acid was site-specifically labelledin vivoby a d-TCO derivative. The fastest bioorthogonal reaction reported to date [k23,300,000 (+/- 40,000) M-1s-1in H2O at 25 °C] is described herein with a cyclopropane-fusedtrans-cyclooctene. d-TCO derivatives display rates within an order of magnitude of these fastesttrans-cyclooctene reagents, and also display enhanced stability and aqueous solubility.
authors.affiliation: Brown Laboratory, Department of Chemistry & Biochemistry, University of Delaware, Newark, Delaware 19716, United States.
authors.forename: Ampofo
authors.initials: A
authors.lastname: Darko
authors.affiliation: Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, United Kingdom.
authors.forename: Stephen
authors.initials: S
authors.lastname: Wallace
authors.affiliation: Brown Laboratory, Department of Chemistry & Biochemistry, University of Delaware, Newark, Delaware 19716, United States.
authors.forename: Olga
authors.initials: O
authors.lastname: Dmitrenko
authors.affiliation: Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331, United States.
authors.forename: Melodie M
authors.initials: MM
authors.lastname: Machovina
authors.affiliation: Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331, United States.
authors.forename: Ryan A
authors.initials: RA
authors.lastname: Mehl
authors.affiliation: Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, United Kingdom.
authors.forename: Jason W
authors.initials: JW
authors.lastname: Chin
authors.affiliation: Brown Laboratory, Department of Chemistry & Biochemistry, University of Delaware, Newark, Delaware 19716, United States.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Fox