| Electronic Journal of Biotechnology
ISSN: 0717-3458 |
Vol. 7 No. 3, Issue of December 15, 2004 |
| © 2004 by Pontificia Universidad Católica
de Valparaíso -- Chile |
Received May 10, 2004 / Accepted September 10, 2004 |
Isolation,
purification, and characterization of L-glutamate oxidase from Streptomyces
sp. 18G
Supawadee
Wachiratianchai
Department
of Biotechnology
Faculty
of Science, Mahidol University
Rama
6 Road, Bangkok 10400 Thailand
Tel:
662 2015310
Fax: 662
2463026
E-mail:
g4236968@student.mahidol.ac.th
Amaret
Bhumiratana
Department
of Biotechnology
Faculty
of Science, Mahidol University
Rama
6 Road, Bangkok 10400 Thailand
Tel:
662 2015310
Fax: 662
2463026
E-mail:
scabr@mahidol.ac.th
Suchat
Udomsopagit*
National
Center for Biotechnology
and Genetic Engineering
National
Science and Technology Development Agency
113
Phaholyothin Road, Klong 1, Klong Luang
Rangsit,
Pathumthani 12120,
Thailand
Tel:
662 5646700 ext 3423
Fax: 662
5646701-5
E-mail:
suchat@biotec.or.th
*Corresponding
author
Financial
support: Grant
PDF/15/2542 from Thailand Research Fund.
Keywords:L-glutamate,
L-glutamate oxidase, purification, screening, Streptomyces.
Abbreviations:
GDC: Glutamate decarboxylase
GDH: Glutamate
dehydrogenase;
GLOD:
L-glutamate oxidase.
An extracellular L-glutamate
oxidase (GLOD) was purified from soil-isolated Streptomyces sp
18G. The enzyme had a molecular weight of approximately 120,000 and
consisted of two identical subunits, each with a molecular weight
of 61,000. The isoelectric point was pH 8.5 and the enzyme had an
optimal pH between 7.0-7.4. GLOD showed the maximum activity at 37ºC.
The GLOD activity was stable at pH ranging from 6.5 to 7.0 for 1 hr.
Among 21 amino acids tested for substrate specificity, L-glutamate
was almost exclusively oxidized. D-glutamate and L-aspartate were
oxidized but only to extents of 0.79% and 0.53%, respectively.
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