Comparison of Ca2+/calmodulin-dependent protein kinase II purified from control and diisopropyl phosphorofluoridate (DFP)-treated hens.


Journal Article

Diisopropyl phosphorofluoridate (DFP) produces type I organophosphorus ester-induced delayed neurotoxicity in humans and sensitive animal species. This is accompanied by enhanced Ca2+/CaM-dependent protein kinase II (CaM-kinase II) activity, and [125I]calmodulin binding to CaM-kinase II in DFP-treated hen brain supernatant without increase in the enzyme quantity. We have purified CaM-kinase II from control and DFP-treated hen whole brains and compared various physical and biochemical properties. The two enzymes exhibited similar properties in many respects. However, there was a decrease in calcium-independent protein kinase II activity after autophosphorylation, and an increase in K0.5 for free calcium and calmodulin of enzyme purified from DFP-treated hen brains. This change in kinetic parameters may result in greater percentage of total CaM-kinase II present in unphosphorylated form, which is consistent with the increased autophosphorylation of CaM-kinase II and [125I]calmodulin binding in the brain supernatant of DFP-treated hens.

Full Text

Duke Authors

Cited Authors

  • Gupta, RP; Abou-Donia, MB

Published Date

  • March 1, 1993

Published In

Volume / Issue

  • 18 / 3

Start / End Page

  • 259 - 269

PubMed ID

  • 8386810

Pubmed Central ID

  • 8386810

International Standard Serial Number (ISSN)

  • 0364-3190

Digital Object Identifier (DOI)

  • 10.1007/BF00969081


  • eng

Conference Location

  • United States