Supramolecular Approach to Electron Paramagnetic Resonance Distance Measurement of Spin-Labeled Proteins.

ABSTRACT: We demonstrate a host-guest molecular recognition approach to advance double electron-electron resonance (DEER) distance measurements of spin-labeled proteins. We synthesized an iodoacetamide derivative of 2,6-diazaadamantane nitroxide (DZD) spin label that could be doubly incorporated into T4 Lysozyme (T4L) by site-directed spin labeling with efficiency up to 50% per cysteine. The rigidity of the fused ring structure and absence of mobile methyl groups increase the spin echo dephasing time (T_m) at temperatures above 80 K. This enables DEER measurements of distances >4 nm in DZD-labeled T4L in glycerol/water at temperatures up to 150 K with increased sensitivity compared to that of a common spin label such as MTSL. Addition of β-cyclodextrin reduces the rotational correla

SUBMITTER: Yang Z 

PROVIDER: S-EPMC8256814 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature