Improvement in protein HSQC spectra from addition of betaine
Improvement in protein HSQC spectra from addition of betaine
Addition of glycine betaine up to 1 M gave rise to increased intensity for some weak signals in the HSQC spectra of barnase and Plasmodium falciparum flap endonuclease. The signals that were enhanced were low intensity signals, often from amide groups with rapid internal motion (low order parameter). The majority of signals are however somewhat weaker because of the increased viscosity. Addition of betaine is shown to cause a small but significant overall increase in order parameter, no consistent effect on conformational...
Improved spectral resolution of [13C,1H]-HSQC spectra of aromatic amino acid residues in proteins produced by cell-free synthesis from inexpensive 13C-labelled precursors
Improved spectral resolution of -HSQC spectra of aromatic amino acid residues in proteins produced by cell-free synthesis from inexpensive 13C-labelled precursors
Abstract
Cell-free protein synthesis using eCells allows production of amino acids from inexpensive 13C-labelled precursors. We show that the metabolic pathway converting pyruvate, glucose and erythrose into aromatic amino acids is maintained in eCells. Judicious choice of 13C-labelled starting material leads to proteins, where the sidechains of aromatic amino acids display -HSQC cross-peaks...
nmrlearner
Journal club
0
06-20-2023 09:01 PM
[U. of Ottawa NMR Facility Blog] Exchange Effects in HSQC Spectra
Exchange Effects in HSQC Spectra
The effects of chemical or dynamic exchange on NMR spectra are very well known. Exchange is often studied by observing line shape changes as a function of temperature, by 2d EXSY, inversion transfer or saturation transfer methods. Effects due to exchange can also be observed in 1H - 13C HSQC spectra. The HSQC method works by transferring 1H magnetization to 13C magnetization via an INEPT transfer through the one-bond J coupling across the 1H - 13C chemical bond. The 13C magnetization evolves during the incremented delay, t1, of the 2D pulse sequence...
nmrlearner
News from NMR blogs
0
01-12-2017 05:31 PM
[NMR paper] ARTSY-J: Convenient and precise measurement of 3JHNH? couplings in medium-size proteins from TROSY-HSQC spectra
ARTSY-J: Convenient and precise measurement of 3JHNH? couplings in medium-size proteins from TROSY-HSQC spectra
Publication date: Available online 3 May 2016
Source:Journal of Magnetic Resonance</br>
Author(s): Julien Roche, Jinfa Ying, Yang Shen, Dennis A. Torchia, Ad Bax</br>
A new and convenient method, named ARTSY-J, is introduced that permits extraction of the 3 J HNH? couplings in proteins from the relative intensities in a pair of 15N-1H TROSY-HSQC spectra. The pulse scheme includes 3 J HNH? dephasing of the narrower TROSY 1HN-{15N} doublet component...
nmrlearner
Journal club
0
05-05-2016 03:15 AM
[U. of Ottawa NMR Facility Blog] Decoupling in 2D HSQC Spectra
Decoupling in 2D HSQC Spectra
HMQC and HSQC NMR data are commonly used to correlate the chemical shifts of protons and 13C (or 15N) across one chemical bond via the J coupling interaction. The data are 1H detected, with the 1H chemical shift in the horizontal F2 domain and the 13C (or 15N) chemical shift in the vertical F1 domain. In the case of 1H and 13C, the technique depends on protons bonded to 13C. 1H–12C spin pairs provide no coupling information and are suppressed by the method. If one is to observe the 1H signal of a 1H-13C spin pair, one expects to observe a doublet with...