A remarkable activity of human leukotriene A4 hydrolase (LTA4H) toward unnatural amino acids |
| |
Authors: | Anna Byzia Jesper Z. Haeggström Guy S. Salvesen Marcin Drag |
| |
Affiliation: | 1. Division of Bioorganic Chemistry, Faculty of Chemistry, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370, Wroc?aw, Poland 2. Division of Chemistry 2, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 77, Stockholm, Sweden 3. Program in Apoptosis and Cell Death Research, Sanford Burnham Medical Research Institute, La Jolla, CA, 92037, USA
|
| |
Abstract: | Leukotriene A4 hydrolase (LTA4H––EC 3.3.2.6) is a bifunctional zinc metalloenzyme, which processes LTA4 through an epoxide hydrolase activity and is also able to trim one amino acid at a time from N-terminal peptidic substrates via its aminopeptidase activity. In this report, we have utilized a library of 130 individual proteinogenic and unnatural amino acid fluorogenic substrates to determine the aminopeptidase specificity of this enzyme. We have found that the best proteinogenic amino acid recognized by LTA4H is arginine. However, we have also observed several unnatural amino acids, which were significantly better in terms of cleavage rate (k cat/K m values). Among them, the benzyl ester of aspartic acid exhibited a k cat/K m value that was more than two orders of magnitude higher (1.75 × 105 M?1 s?1) as compared to l-Arg (1.5 × 103 M?1 s?1). This information can be used for design of potent inhibitors of this enzyme, but may also suggest yet undiscovered functions or specificities of LTA4H. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|