Inactivation of the Na,K‐ATPase by modification of Lys‐501 with 4‐acetamido‐4′‐isothiocyanatostilbene‐2,2′‐disulfonic acid (SITS)

FEBS Letters

Kirley, Torence L.²  Kaplan, Jack H.¹  Pedemonte, Carlos H.¹  Treuheit, Michael J.² 

[1] Department of Physiology, University of Pennsylvania, Philadelphia, PA 19104-6085, USA;Department of Pharmacology and Cell Biophysics, University of Cincinnati, College of Medicine, 231 Bethesda Avenue, Cincinnati, OH 45267-0575, USA

关键词: Na;    K-ATPase;    Enzyme inactivation;    Active transport;    Ion pump;    4-Acetamido-4′-isothiocyanatostilbene-2;    2′-disulfonic acid (SITS);   

DOI  :  10.1016/0014-5793(92)81470-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The sodium pump or Na,K-ATPase, maintains the Na⁺ and K⁺ gradients across eukaryotic cell membranes at the expense of ATP. Incubation of purified canine renal Na,K-ATPase with 4-acetamido-4′-isothiocyanatostilbene-2,2′-disulfonic acid (SITS) inhibited the ATPase activity. Both the labeling of the protein and the loss or ATPase activity were prevented by co-incubation with ADP (acting as an ATP analog) or KCI. Only the α-subunit was labeled by SITS. The α-subunit from the inhibited enzyme was extensively digested with trypsin, and SITS-labeled peptides were purified by reverse-phase HPLC and sequenced. The amino acid sequence determined, His-Leu-Leu-Val-Met-X-Gly-Ala-Pro-Glu, indicated that SITS modifies Lys-501 (X) on the α-subunit of Na,K-ATPase.

【 授权许可】

Unknown