The environments ofTrp‐248 and Trp‐330 in tryptophan indole‐lyase from Escherichia coli

FEBS Letters

Phillips, Robert S.²  Gollnick, Paul¹ 

[1] Department of Biological Sciences, Stanford University, Stanford, CA 94305, USA;Departments of Chemistry and Biochemistry, School of Chemical Sciences, University of Georgia, Athens, GA 30602, USA

关键词: Tryptophan indole-lyase;    E. coli;    Tryptophanase;    Site-directed mutagenesis;    Tryptophan;    Fluorescence;    Circular dichroism;   

DOI  :  10.1016/0014-5793(90)81011-C

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The two tryptophan residues, Trp-248 and Trp-330, in tryptophan indole-lyase (tryptophanase) from E. coli have been separately mutated to phenylalanine using site-directed mutagenesis. Both single tryptophan mutant enzymes have full catalytic activity, but exhibit different fluorescence and near-UV circular dichroism spectra. These results indicate that Trp-330 is more deeply buried than is Trp-248, and is in a more asymmetric environment. Neither residue reacts with N-bromosuccinimide (NBS), although tryptophan indole-lyase is inactivated by NBS. These results demonstrate that the tryptophan residues in tryptophan indole-lyase are not catalytically essential.

【 授权许可】

Unknown