NMR studies of the hydrogen bonds involving the catalytic triad of Escherichia coli thioesterase/protease I

FEBS Letters

Leu, Ruey-Jyh²  Chang, Chi-Fon¹  Tyukhtenko, Sergiy I¹  Shaw, Jei-Fu²  Huang, Tai-Huang¹  Litvinchuk, Alexandra V¹ 

[1] Institute of Biomedical Sciences, Academia Sinica, Nankang, Taipei 11529, Taiwan ROC;Institute of Botany, Academia Sinica, Nankang, Taipei 11529, Taiwan ROC

关键词: Serine protease;    Low barrier hydrogen bond;    Nuclear magnetic resonance;    Lipolytic enzyme;    Thioesterase;   

DOI  :  10.1016/S0014-5793(02)03308-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Escherichia coli thioesterase/protease I (TEP-I) is a lipolytic enzyme of the serine protease superfamily with Ser¹⁰, Asp¹⁵⁴ and His¹⁵⁷ as the catalytic triad residues. Based on comparison of the low-field ¹H nuclear magnetic resonance spectra of two mutants (S10G and S12G) and two transition state analogue complexes we have assigned the exchangeable proton resonances at 16.3 ppm, 14.3 ppm, and 12.8 ppm at pH 3.5 to His¹⁵⁷-N^δ1H, Ser¹⁰-O^γH and His¹⁵⁷-N^ϵ2H, respectively. Thus, the presence of a strong Asp¹⁵⁴–His¹⁵⁷ hydrogen bond in free TEP-I was observed. However, Ser¹⁰-O^γH was shown to form a H-bond with a residue other than His¹⁵⁷-N^ϵ2.

【 授权许可】

Unknown