Multivalent Chelators for In Vivo Protein Labeling

Abstract

With the advent of single‐molecule methods, chemoselective and site‐specific labeling of proteins evolved to become a central aspect in chemical biology as well as cell biology. Protein labeling demands high specificity, rapid as well as efficient conjugation, while maintaining low concentration and biocompatibility under physiological conditions. Generic methods that do not interfere with the function, dynamics, subcellular localization of proteins, and crosstalk with other factors are crucial to probe and image proteins in vitro and in living cells. Alternatives to enzyme‐based tags or autofluorescent proteins are short peptide‐based recognition tags. These tags provide high specificity, enhanced binding rates, bioorthogonality, and versatility. Here, we report on recent applications of multivalent chelator heads, recognizing oligohistidine‐tagged proteins. The striking features of this system has facilitated the analysis of protein complexes by single‐molecule approaches.

Towards unidirectional reconstitution of membrane proteins into liposomes

“…Multiple variants of trisNTA have been reported, essentially differing in the nature of the scaffold carrying the three NTA moieties, such as cyclic, linear, or dendritic trisNTAs. [288] The different variants of trisNTA have been used in numerous studies for a wide variety of applications. trisNTA has for example been used for in situ protein labeling with fluorophores [289], for site-specific orientated attachment of His-tagged proteins on surfaces [290], or to anchor His-tagged proteins to gold nanoparticles for cryo-electron tomography [291], to only name a few.…”

“…trisNTA has for example been used for in situ protein labeling with fluorophores [289], for site-specific orientated attachment of His-tagged proteins on surfaces [290], or to anchor His-tagged proteins to gold nanoparticles for cryo-electron tomography [291], to only name a few. For a recent review highlighting numerous further applications of trisNTA consider Wieneke et al [288]. In summary, trisNTA can be versatilely functionalized, e. g. with fluorophores, quenchers, or gold nanoparticles, and its stoichiometric binding to His-tagged proteins is orthogonal to other protein labeling techniques.…”

“…In summary, trisNTA can be versatilely functionalized, e. g. with fluorophores, quenchers, or gold nanoparticles, and its stoichiometric binding to His-tagged proteins is orthogonal to other protein labeling techniques. [288] To enable coupling of trisNTA to LSUs in aequous solution, we decided to use a tris-NTA functionalized with a primary amine. A variant of such an amino-functionalized trisNTA is commercially available, but 100 µg are e. g. sold for CHF 277.00 by Sigma-Aldrich (tris-NTA amine trifluoroacetate salt solution, Sigma-Aldrich, 14136; 27.01.2020).…”