Gd³⁺-Trityl-Nitroxide Triple Labeling and Distance Measurements in the Heterooligomeric Cobalamin Transport Complex in the Native Lipid Bilayers.

ABSTRACT: Increased efforts are being made for observing proteins in their native environments. Pulsed electron-electron double resonance spectroscopy (PELDOR, also known as DEER) is a powerful tool for this purpose. Conventionally, PELDOR employs an identical spin pair, which limits the output to a single distance for monomeric samples. Here, we show that the Gd³⁺-trityl-nitroxide (NO) three-spin system is a versatile tool to study heterooligomeric membrane protein complexes, even within their native membrane. This allowed for an independent determination of four different distances (Gd³⁺-trityl, Gd³⁺-NO, trityl-NO, and Gd³⁺-Gd³⁺) within the same sample. We demonstrate the feasibility of this approach by observing sequential ligand binding and

SUBMITTER: Ketter S 

PROVIDER: S-EPMC9853854 | biostudies-literature | 2023 Jan

REPOSITORIES: biostudies-literature