title: Dual-band selective double cross polarization for heteronuclear polarization transfer between dilute spins in solid-state MAS NMR.
abstract: A sinusoidal modulation scheme is described for selective heteronuclear polarization transfer between two dilute spins in double cross polarization magic-angle-spinning nuclear magnetic resonance spectroscopy. During the second N→C cross polarization, the (13)C RF amplitude is modulated sinusoidally while the (15)N RF amplitude is tangent. This modulation induces an effective spin-lock field in two selective frequency bands in either side of the (13)C RF carrier frequency, allowing for simultaneous polarization transfers from (15)N to (13)C in those two selective frequency bands. It is shown by experiments and simulations that this sinusoidal modulation allows one to selectively polarize from (15)N to its covalently bonded (13)Cα and (13)C' carbons in neighboring peptide planes simultaneously, which is useful for establishing the backbone connectivity between two sequential residues in protein structural elucidation. The selectivity and efficiency were experimentally demonstrated on a uniformly (13)C,(15)N-labeled β1 immunoglobulin binding domain of protein G (GB1).
authors.affiliation: Wuhan Center for Magnetic Resonance, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Science, Wuhan 430071, PR China.
authors.forename: Zhengfeng
authors.initials: Z
authors.lastname: Zhang
authors.forename: Yimin
authors.initials: Y
authors.lastname: Miao
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Liu
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.forename: Conggang
authors.initials: C
authors.lastname: Li
authors.forename: Feng
authors.initials: F
authors.lastname: Deng
authors.forename: Riqiang
authors.initials: R
authors.lastname: Fu
mesh_terms: D000465:Algorithms; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D013113:Spin Labels
chemical_list: D013113:Spin Labels