PURIFICATION AND CHARACTERIZATION OF A THERMOSTABLE CATALASE FROM CULTURE BROTH OF THERMOASCUS-AURANTIACUS

Citation
Hx. Wang et al., PURIFICATION AND CHARACTERIZATION OF A THERMOSTABLE CATALASE FROM CULTURE BROTH OF THERMOASCUS-AURANTIACUS, Journal of fermentation and bioengineering, 85(2), 1998, pp. 169-173
Citations number
16
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Food Science & Tenology","Biothechnology & Applied Migrobiology
ISSN journal
0922-338X
Volume
85
Issue
2
Year of publication
1998
Pages
169 - 173
Database
ISI
SICI code
0922-338X(1998)85:2<169:PACOAT>2.0.ZU;2-C
Abstract
A thermostable catalase from the culture broth of Thermoascus aurantia cus grown on ethanol was purified as an electrophoretically and isoele ctrophoretically homogeneous protein. The molecular weights of the nat ive enzyme and its subunit were estimated to be approximately 330,000 and 75,000 by gel filtration chromatography and SDS-polyacrylamide gel electrophoresis, respectively. The enzyme was proven to be a homo-tet rameric hemecatalase with one iron atom per subunit and about 11% carb ohydrate. The pi was 4.5. The enzyme was stable up to 80 degrees C and over a wide range of pH from 5 to 13. The optimum pH was in the range of 6 to 10 and the optimum temperature was 70 degrees C. The Km and K -cat of the enzyme for hydrogen peroxide were 4.8 x 10(-2) M and 1.07 x 10(5) s(-1). respectively. The enzyme was strongly inhibited by pota ssium cyanide and sodium azide.