Effects of canatoxin on the Ca(2+)-ATPase of sarcoplasmic reticulum membranes

Toxicon. 1992 Nov;30(11):1411-8. doi: 10.1016/0041-0101(92)90516-8.

Abstract

Canatoxin, a toxic protein isolated from the seeds of Canavalia ensiformis, was studied for its effects on the sarcoplasmic reticulum vesicles obtained from rabbit skeletal muscle. Canatoxin inhibited Ca2+ accumulation catalysed by the Ca(2+)-ATPase, without affecting the hydrolytic activity of this enzyme or membrane permeability to Ca2+. The effects of canatoxin were dose dependent, but not time dependent. It is concluded that canatoxin interacts with the Ca2+ pump and uncouples Ca2+ uptake from Ca(2+)-dependent ATP hydrolysis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Animals
  • Ca(2+) Mg(2+)-ATPase / metabolism
  • Calcium / metabolism
  • Calcium-Transporting ATPases / antagonists & inhibitors*
  • In Vitro Techniques
  • Lectins / pharmacology*
  • Membranes / drug effects
  • Membranes / enzymology
  • Muscles / drug effects
  • Muscles / metabolism
  • Plant Proteins*
  • Rabbits
  • Sarcoplasmic Reticulum / drug effects
  • Sarcoplasmic Reticulum / enzymology*
  • Toxins, Biological*

Substances

  • Lectins
  • Plant Proteins
  • Toxins, Biological
  • canatoxin
  • Adenosine Triphosphate
  • Ca(2+) Mg(2+)-ATPase
  • Calcium-Transporting ATPases
  • Calcium