Synthesis and application of novel bifunctional spin labels.
The synthesis of new bifunctional spin-labeled cross-linking reagents is described. Covalent attachment to papain was achieved via a thiol-specific thiosulfonate residue and, for the second anchor point, via a nonspecific photoreactive azido function. The thiosulfonate formed a reversible disulfide linkage, which could be cleaved again reductively by dithiothreitol. The spin label, a pyrroline-1-oxyl radical, was highly immobilized after attachment to papain by both functional groups and showed little if any relative motion with respect to the protein.
Lösel
R M
RM
Fachbereich Chemie, Universität Kaiserslautern, P.O. Box 3049, D-67653 Kaiserslautern, Germany.
Philipp
R
R
Kálai
T
T
Hideg
K
K
Trommer
W E
WE
D003432:Cross-Linking Reagents; D004229:Dithiothreitol / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy; D007202:Indicators and Reagents; D008958:Models, Molecular; D010206:Papain / Q000737:chemistry; D010782:Photolysis; D013113:Spin Labels / Q000138:chemical synthesis*; D013439:Sulfhydryl Reagents / Q000737:chemistry
D003432:Cross-Linking Reagents; D007202:Indicators and Reagents; D013113:Spin Labels; D013439:Sulfhydryl Reagents; D010206:Papain; D004229:Dithiothreitol