Direct NMR resonance assignments of the active site histidine residue in Escherichia coli thioesterase I/protease I/lysophospholipase L1

✍ Scribed by Wen-Jin Wu; Sergiy I. Tyukhtenko; Tai-Huang Huang

• Book ID: 102525718
• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 156 KB
• Volume: 44
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1901

✦ Synopsis

Abstract

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.