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Direct NMR resonance assignments of the active site histidine residue in Escherichia coli thioesterase I/protease I/lysophospholipase L 1
Author(s) -
Wu WenJin,
Tyukhtenko Sergiy I.,
Huang TaiHuang
Publication year - 2006
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.1901
Subject(s) - chemistry , histidine , thioesterase , active site , residue (chemistry) , escherichia coli , protease , proton nmr , proton , stereochemistry , catalysis , nuclear magnetic resonance , enzyme , organic chemistry , biochemistry , biosynthesis , physics , gene , quantum mechanics
Owing to the hydrogen‐bond interaction and rapid exchange rate with the bulk water, the transverse relaxation time for the N δ1 H proton of the catalytic histidine in Escherichia coli thioesterase I/protease I/lysophospholipase L 1 (TEP‐I) is rather short. Because of its catalytic importance, it is desirable to detect and assign this proton resonance. In this paper, we report the first direct NMR correlation between the short‐lived N δ1 H proton and its covalently attached N δ1 –nitrogen of the catalytic His157 residue in E. coli thioesterase/protease I. We have used gradient‐enhanced jump‐return spin‐echo HMQC (GE‐JR SE HMQC) to obtain a direct correlation between the short‐lived N δ1 H proton and its covalently attached N δ1 –nitrogen. The sensitivity of detection for the short‐lived N δ1 H proton was enhanced substantially by improved water suppression, in particular, the suppression of radiation damping via pulsed field gradients. Copyright © 2006 John Wiley & Sons, Ltd.