Open AccessStable Europium(III) Complexes with Short Linkers for Site‐Specific Labeling of Biomolecules
Author(s) -
Faschinger Felix,
Ertl Martin,
Zimmermann Mirjam,
Horner Andreas,
Himmelsbach Markus,
Schöfberger Wolfgang,
Knör Günther,
Gruber Hermann J.
Publication year - 2017
Publication title -
chemistryopen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 29
ISSN - 2191-1363
DOI - 10.1002/open.201700122
Subject(s) - chemistry , europium , biomolecule , linker , ethylene glycol , cysteine , combinatorial chemistry , guanosine , ion , organic chemistry , biochemistry , enzyme , computer science , operating system
In this study, two new terpyridine‐based Eu III complexes were synthesized, the structures of which were optimized for luminescence resonance energy‐transfer (LRET) experiments. The complexes showed high quantum yields (32 %); a single long lifetime (1.25 ms), which was not influenced by coupling to protein; very high stability in the presence of chelators such as ethylenediamine‐ N , N , N ′, N ′‐tetraacetate and ethylene glycol‐bis(2‐aminoethylether)‐ N , N , N ′, N ′‐tetraacetic acid; and no interaction with cofactors such as adenosine triphosphate and guanosine triphosphate. A special feature is the short length of the linker between the Eu III ion and the maleimide or hydrazide function, which allows for site‐specific coupling of cysteine mutants or unnatural keto amino acids. As a consequence, the new complexes appear particularly suited for accurate distance measurements in biomolecules by LRET.