The use of TROSY for detection and suppression of conformational exchange NMR line broadening in biological macromolecules.
The interference between conformational exchange-induced time-dependent variations of chemical shifts in a pair of scalar coupled 1H and 15N spins is used to construct novel TROSY-type NMR experiments to suppress NMR signal loss in [15N,1H]-correlation spectra of a 14-mer DNA duplex free in solution and complexed with the Antp homeodomain. An analysis of double- and zero-quantum relaxation rates of base 1H-15N moieties showed that for certain residues the contribution of conformational exchange-induced transverse relaxation might represent a dominant relaxation mechanism, which, in turn, can be effectively suppressed by TROSY. The use of the new TROSY method for exchange-induced transverse relaxation optimization is illustrated with two new experiments. 2D h1J(HN),h2J(NN) quantitative [15N,1H]-TROSY to measure h1J(HN) and h2J(NN) scalar coupling constants across hydrogen bonds in nucleic acids, and 2D (h2J(NN) + h1J(NH))-correlation-[15N,1H]-TROSY to correlate 1H(N) chemical shifts of bases with the chemical shifts of the tertiary 15N spins across hydrogen bonds using the sum of the trans-hydrogen bond coupling constants in nucleic acids.
Pervushin
K
K
Laboratorium für Physikalische Chemie, Eidgenössische Technische Hochschule, Zürich, Switzerland.
D000818:Animals; D051943:Antennapedia Homeodomain Protein; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D029721:Drosophila Proteins / Q000737:chemistry / Q000378:metabolism; D018398:Homeodomain Proteins / Q000737:chemistry / Q000378:metabolism; D006859:Hydrogen / Q000032:analysis; D006860:Hydrogen Bonding; D009587:Nitrogen Isotopes / Q000032:analysis; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D009687:Nuclear Proteins; D009690:Nucleic Acid Conformation; D011487:Protein Conformation; D014157:Transcription Factors
D051943:Antennapedia Homeodomain Protein; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D009587:Nitrogen Isotopes; D009687:Nuclear Proteins; D014157:Transcription Factors; D006859:Hydrogen; D004247:DNA