Effect of divalent cations on Na+,K+‐ATPase obtained from human placenta

FEBS Letters

Gratton, E.²  Zolese, G.¹  Mazzanti, L.¹  Staffolani, R.¹ 

[1] Istituto di Biochimica, Facoltà di Medicina, 60100 Ancona, Italy;University of Illinois, Department of Physics, Laboratory for Fluorescence Dynamics, Urbana, IL, USA

关键词: Na+;    K+-ATPase;    Human placenta;    Fluorescence;    Quenching;    Circular dichroism;   

DOI  :  10.1016/0014-5793(93)81437-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Circular dichroism (CD) and acrylamide quenching studies of Na⁺,K⁺-ATPase from human placenta showed that its incorporation into phosphatidylcholine vesicles increased the enzymic activity by 55%. Moreover, both with the purified and the vesicle-reconstituted protein, Ca²⁺ and Mg²⁺ increased the activity, the effect being more pronounced after preincubation of the protein with Mg²⁺. CD data suggest that this activity increase may be linked to a change in the secondary structure of the ATPase, in particular β-turn, β-sheet and random coil. Acrylamide quenching studies suggest that ions could primarily interact with phospholipid head groups, but not directly with the protein.

【 授权许可】

Unknown