Effects of Metal-ions on Enzyme Activities from Hansenula anomala B-7 Grown in Medium Containing Cadmium

카드뮴 함유 배지에서 배양된 Hansenula anomala B-7의 Malate Dehydrogenase 활성에 미치는 금속 이온의 영향

  • Yu, Tae Shick (Department of Microbiology, Keimyung University)
  • 유대식 (계명대학교 미생물학과)
  • Received : 1998.08.10
  • Accepted : 1998.11.04
  • Published : 1998.12.01

Abstract

This study was carried out to investigate the effect of cadmium ion on activities of cadmium-adapted malate dehydrogenase (adapted-MDH), which is defined to be an enzyme obtained from an extreme cadmium-tolerant yeast Hansenula anomaul B-7 grown in medium containing 1 mM cadmium ion. Cadmium-nonadapted malate dehydrogenase (nonadapted-MDH), which is defined to be enzyme expressed in the cells grown in $Cd^{2+}$ -free medium was also characterized by the same manner. Activities of the adapted-MDH and the nonadapted-MDH were strongly induced to 450% and to 150% in comparision with the control examined with 1 mM $Cd^{2+}$, respectively. The adapted-MDH activity was stimulated to 147%, 150%, and 135% compared with the control analyzed with 1 mM $Zn^{2+}$, 1 mM $Mn^{2+}$, and 1 mM $Ca^{2+}$, respectively and to 925%, and 250% compared with the control analyzed in the presence of 2 mM $Cd^{2+}$, and 2.5 mM $Zn^{2+}$, respectively. Km values of the adapted-MDH and the nonadapted-MDH were calculated to be the same 6.9 mM for L-malate, respectively. The Km value of the nonadapted-MDH was not changed by $Cd^{2+}$ while Vmax of the nonadapted-MDH was increased by $Cd^{2+}$. In contrast, both the Km and the Vmax values of the adapted-MDH were changed by $Cd^{2+}$.

Keywords

malate dehydrogenase;cadmium;Hansenula anomala B-7

Acknowledgement

Grant : 카드뮴 함유배지에서 배양된 Hansenula anomala B-7의 효소활성에 미치는 금속이온의 영향

Supported by : 계명대학교