Current time in Korea 09:54 Dec 03 (Thu) Year 2020 KCS KCS Publications
KCS Publications
My Journal  Log In  Register
HOME > Search > Browsing(BKCS) > Archives

Bulletin of the Korean Chemical Society (BKCS)

ISSN 0253-2964(Print)
ISSN 1229-5949(Online)
Volume 23, Number 8
BKCSDE 23(8)
August 20, 2002 

Activation Changes of Hafnia alvei Aspartase by Acetic Anhydride
Im-Joung La, Joungmok Kim, Jeong-Rim Kim, Ki-Tae Kim, Jung-Sung Kim, Moon-Young Yoon
Aspartase, Hafnia alvei, Chemical modification
The Hafnia alvei aspartase activity with acetic anhydride treatment gradually increased and reached 7.5-fold that of the native one. The activity of the acetylated aspartase was a little higher than that of the native enzyme, indicating that the cooperativity between a substrate and enzyme is increased. The optimum temperature of the native asparatse was 45℃, and that of the acetylated enzyme shifted to 40℃. The pH vs. the activity profile of the acetylated asparatse was also different from that of the native enzyme. The initial velocity pattern of the acetylated aspartase intersects to the left of the ordinate, indicating the sequential kinetic mechanism other than a rapid equilibrium ordered one. The reciprocal plots for aspartate of the native aspartase were curved, but those of the acetylated aspartase were linear, indicating the Michaelis-Menten kinetics. The helical content of the acetylated aspartase was rather decreased to 9‰ than that (63‰) of the native one.
1057 - 1061
Full Text