Site-directed spin labeling

The theory of SDSL is based on the specific reaction of spin labels with amino acids.

[2][3] In SDSL, sites for attachment of spin labels are introduced into recombinantly expressed proteins by site-directed mutagenesis.

[4] Spin labels are a unique molecular reporter, in that they are paramagnetic (contain an unpaired electron).

[5] Since then, a variety of nitroxide spin labels have enjoyed widespread use for the study of macromolecular structure and dynamics because of their stability and simple EPR signal.

[8] A 2012 study generated a high resolution structure of IAPP fibrils using a combination of SDSL, pulse EPR and computational biology.