Development of polyproline linked bifunctional crosslinkers as molecular rulers for the structural investigation of protein assemblies

摘要

The structural elucidation of protein or nucleic acid assemblies by covalent labeling and mass spectrometry is limited by the narrow selection of bifunctional reagents with different target specificity and crosslinking range. We have recently developed crosslinkers consisting of two identical 1,2-dicarbonyl functionalities connected by modular benzene spacers, which provided the proof of principle for molecular rulers capable of spanning different distances on target substrates. In comparison with typical reagents with aliphatic spacer chains, these probes afforded reduced flexibility and fewer rotational degrees, thus affording more narrowly defined crosslinking ranges and more precise distance constraints. Their practical application, however, highlighted the need for greater stability and solubility under typical liquid chromatography conditions.