Ouabain-insensitive Na+-ATPase activity of malpighian tubules from Rhodnius prolixus

被引：29

作者：

Caruso-Neves, C

Meyer-Fernandes, JR

Saad-Nehme, J

Proverbio, F

Marin, R

Lopes, AG

机构：

[1] Univ Fed Rio de Janeiro, Inst Biofis Carlos Chagas Filho, BR-21949900 Rio De Janeiro, Brazil

[2] Univ Fed Rio de Janeiro, Inst Ciencias Biomed, Dept Bioquim Med, BR-21949900 Rio De Janeiro, Brazil

[3] Inst Venezolano Invest Cient, Ctr Biofis & Bioquim, Caracas 1020A, Venezuela

来源：

COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY B-BIOCHEMISTRY & MOLECULAR BIOLOGY | 1998年 / 119卷 / 04期

关键词：

furosemide-sensitive; ATPase activity; Malpighian tubular cells;

D O I：

10.1016/S0305-0491(98)00057-1

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

In the present paper, we show the existence of a furosemide-sensitive Na+-stimulated, Mg2+-dependent ATPase activity in cell lysates of Malpighian tubular cells from Rhodnius prolixus, which could be the biochemical expression of the Na+-pump. The main characteristics of this activity are: (1) K-0.5 for Na+ = 1.49 +/- 0.18 mM, (2) V-max = 2.8 +/- 0.1 nmol inorganic orthophosphate (Pi).mg prot(-1).min(-1), (3) it is fully abolished by 2 mM furosemide, (4) it is insensitive to ouabain concentrations up to 10(-2) M, (5) it is sensitive to the presence of vanadate in the incubation medium indicating it to be a P-type ATPase, and (6) it is stimulated by nanomolar concentrations of Ca2+ in the incubation medium. (C) 1998 Elsevier Science Inc. All rights reserved.

引用

页码：807 / 811

页数：5

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