화학공학소재연구정보센터
Biochemical and Biophysical Research Communications, Vol.363, No.1, 51-56, 2007
A native Zn/Cd pumping P-1B ATPase from natural overexpression in a hyperaccumulator plant
We report here the first purification of a P-1B type ATPase, a group of transporters that occurs in bacteria, plants and animals incl. humans, from a eukaryotic organism in native state. TcHMA4 is a P-1B type ATPase that is highly expressed in the Cd/Zn hyperaccumulator plant Thlaspi caerulescens and contains a C-terminal 9-histidine repeat. After isolation from roots, we purified TcHMA4 protein via metal affinity chromatography. The purified protein exhibited Cd- and Zn-activated ATPase activity after reconstitution into lipid vesicles, showing that it was in its native state. Gels of crude root extract and of the purified protein revealed TcHMA4-specific bands of about 50 and 60 kDa, respectively, while the TcHMA4 mRNA predicts a single protein with a size of 128 kDa. This indicates the occurrence of post-translational processing; the properties of the two bands were characterised by their activity and binding properties. (C) 2007 Elsevier Inc. All rights reserved.