In cell Gd3+-based site-directed spin labeling and EPR spectroscopy of eGFP

Abstract

Label-based functional studies of biomolecules in their native environment require labeling reactions inside living cells. In cell spin labeling using alkyne–azide click chemistry with a Gd³⁺-DOTAM-azide complex is shown to provide high spin label stability and narrow EPR lines for EPR spectroscopic detection of a spin labeled protein in living cells at ambient temperatures.