Measurement of 3hJNC' connectivities across hydrogen bonds in a 30 kDa protein.
A method is described which permits detection of 3hJNC' scalar couplings across hydrogen bonds in larger, perdeuterated proteins. The experiment is demonstrated for the uniformly 2H/13C/15N-enriched 30 kDa ribosome inactivating protein MAP30. The 3hJNC' interactions are smaller than 1 Hz, but their detection in an HNCO experiment is made possible through the use of constructive interference between the 15N chemical shift anisotropy and 1H-15N dipole-dipole relaxation mechanisms in a manner similar to that of recently proposed TROSY schemes. Sensitivity of the HNCO experiment depends strongly on the 15N transverse relaxation rate of the downfield 15N multiplet component and on the amide proton T1. In perdeuterated MAP30 at 40 degrees C, the average TROSY T2 was 169 ms at 750 MHz 1H frequency, and a wide range of longitudinal relaxation rates was observed for the amide protons.
Wang
Y X
YX
Molecular Structural Biology Unit, National Institute of Dental Research, National Institutes of Health, Bethesda, MD 20892-0520, USA.
Jacob
J
J
Cordier
F
F
Wingfield
P
P
Stahl
S J
SJ
Lee-Huang
S
S
Torchia
D
D
Grzesiek
S
S
Bax
A
A
D002247:Carbon Isotopes; D003903:Deuterium; D006860:Hydrogen Bonding; D009587:Nitrogen Isotopes; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D017433:Protein Structure, Secondary; D011506:Proteins / Q000737:chemistry*; D054788:Ribosome Inactivating Proteins; D054790:Ribosome Inactivating Proteins, Type 2
D002247:Carbon Isotopes; C066347:MAP30 protein, Momordica charantia; D009587:Nitrogen Isotopes; D011506:Proteins; D054790:Ribosome Inactivating Proteins, Type 2; D003903:Deuterium; D054788:Ribosome Inactivating Proteins