Activation of the purified erythrocyte plasma membrane Ca2+‐ATPase by organic solvents

FEBS Letters

Benaim, Gustavo¹  de Meis, Leopoldo¹ 

[1] Instituto de Ciencias Biomedicas, Departamento de Bioquimica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21910, Brazil

关键词: ATPase;    Ca2+-;    Calmodulin;    Organic solvent;    Plasma membrane;    Hydrophobic interaction;    (Human erythrocyte);   

DOI  :  10.1016/0014-5793(89)80589-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

In this report it is shown that organic solvents mimic the stimulatory effects of calmodulin and acidic phospholipids on the erythrocyte plasma membrane Ca²⁺-ATPase. The solvents used were dimethyl sulfoxide (20%, v/v), glycerol (20%, v/v), ethylene glycol (20%, v/v) and polyethylene glycol (M _r, 6000–8000) (10%, w/v). These solvents increased both the affinity for Ca²⁺ and the turnover number of the enzyme. The increase in Ca²⁺ affinity is additive to that achieved with calmodulin. The calcium cooperativity observed in the presence of calmodulin disappears after the addition of dimethyl sulfoxide to the medium. The present data support the proposal that activation of the erythrocyte plasma membrane Ca²⁺-ATPase is promoted by hydrophobic interactions along the enzyme molecule.

【 授权许可】

Unknown