The homo bifunctional linker DBCO-PEG4-DBCO contains two DBCO moieties which enable reaction with two azides. This linker is well suited for cross linking when used in excess ^[1,2] but enables other interesting possibilities as circularization of biomolecules containing two azides. The hydrophilic PEG4 spacer increase water solubility needed for reaction with biomolecules in aqueous media.

LITERATURE

[1] Generation of therapeutic protein variants with the human serum albumin binding capacity via site-specific fatty acid conjugation, J. Cho et al., 2017, Scientific Reports, Vol. 7(1), 18041.

https://doi.org/10.1038/s41598-017-18029-y

[2] An expanded genetic code facilitates antibody chemical conjugation involving the lambda light chain, A. Kato et al., 2021, Biochemical and Biophysical Research Communications, Vol. 546, p. 35-39.

https://doi.org/10.1016/j.bbrc.2021.02.005

Characterization and scaled-up production of azido-functionalized silk fiber produced by transgenic silkworms with an expanded genetic code, H. Teramoto et al., 2019, International Journal of Molecular Sciences, Vol. 20(3), 616.

https://doi.org/10.3390/ijms20030616