title: Spin label studies of the essential sulfhydryl group environment in chicken liver fructose-1,6-bisphosphatase.
abstract: The local environment of the essential sulfhydryl groups in chicken liver fructose-1,6-bisphosphatase has been investigated by ESR techniques using a series of iodoacetamide spin labels, varying in chain length between the iodoacetate and nitroxide free radical group. The ESR spectrum of spin-labeled chicken liver fructose-1,6-bisphosphatase showed that the sites of labeling were highly immunobilized when the enzyme was chemically modified by spin label iodoacetate, suggesting that the sulfhydryl groups of the protein are in a small, confined environment. From the change in the ESR spectra of these nitroxides as a function of chain length, we conclude that the sulfhydryl group is located in a cleft approx. 10.5A in depth.
mesh_terms: D000818:Animals; D002645:Chickens; D004578:Electron Spin Resonance Spectroscopy; D006597:Fructose-Bisphosphatase / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D013113:Spin Labels / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D013438:Sulfhydryl Compounds / Q000032:analysis
chemical_list: D013113:Spin Labels; D013438:Sulfhydryl Compounds; D006597:Fructose-Bisphosphatase