title: Separating Dipolar and Chemical Exchange Magnetization Transfer Processes in1H-CEST.
abstract: An amide1H-Chemical Exchange Saturation Transfer (CEST) experiment is presented for studies of conformational exchange in proteins. The approach, exploiting spin-state-selective magnetization transfer, completely suppresses undesired NOE-based dips in CEST profiles so that chemical exchange processes can be studied. The methodology is demonstrated with applications involving proteins that interconvert on the millisecond timescale between major and invisible minor states, and accurate amide1H chemical shifts of the minor conformer are obtained in each case. The spin-state-selective magnetization transfer approach offers unique possibilities for quantitative studies of protein exchange through1H-CEST.
authors.affiliation: Departments of Molecular Genetics, Biochemistry, and Chemistry, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.
authors.forename: Tairan
authors.identifier: 0000-0003-3504-7995
authors.initials: T
authors.lastname: Yuwen
authors.affiliation: Departments of Molecular Genetics, Biochemistry, and Chemistry, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.
authors.forename: Ashok
authors.initials: A
authors.lastname: Sekhar
authors.affiliation: Departments of Molecular Genetics, Biochemistry, and Chemistry, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.|Hospital for Sick Children, Program in Molecular Structure and Function, 555 University Avenue, Toronto, Ontario, M5G 1X8, Canada.
authors.forename: Lewis E
authors.initials: LE
authors.lastname: Kay
keywords: amide protons; conformational dynamics; cross relaxation; proteins; proton CEST