Inactivation and self-association of Ca2+/calmodulin-dependent protein kinase II during autophosphorylation

Andy Hudmon, Jaroslaw Aronowski, Stephen J. Kolb, M. Neal Waxham

Research output: Contribution to journalArticle

50 Citations (Scopus)

Abstract

The time-dependent loss in enzyme activity associated with the autophosphorylation of Ca2+/calmodulin-dependent protein kinase II (CaM-kinase) was altered by both pH and ATP concentration. These parameters also influenced the extent to which soluble CaM-kinase undergoes self-association to form large aggregates of sedimentable enzyme. Specifically, autophosphorylation of CaM-kinase in 0.01 mM ATP at pH 6.5 resulted in the formation of sedimentable enzyme and a 70% loss of enzyme activity. Under similar conditions at pH 7.5, the enzyme lost only 30% of its activity, and no sedimentable enzyme was detected. In contrast to 0.01 mM ATP, autophosphorylation of CaM-kinase at pH 6.5 in 1 mM ATP did not result in a loss of activity or the production of sedimentable enzyme, even though the stoichiometry of autophosphorylation was comparable. Electron microscopy studies of CaM-kinase autophosphorylated at pH 6.5 in 0.01 mM ATP revealed particles 100-300 nm in diameter that clustered into branched complexes. Inactivation and self-association of CaM-kinase were influenced by the conditions of autophosphorylation in vitro, suggesting that both the catalytic and physical properties of the enzyme may be sensitive to fluctuations in ATP concentration and pH in vivo.

Original languageEnglish (US)
Pages (from-to)8800-8808
Number of pages9
JournalJournal of Biological Chemistry
Volume271
Issue number15
StatePublished - Apr 12 1996
Externally publishedYes

Fingerprint

Calcium-Calmodulin-Dependent Protein Kinase Type 2
Adenosine Triphosphate
Association reactions
Enzymes
Enzyme activity
Stoichiometry
Electron microscopy
Physical properties
Electron Microscopy

ASJC Scopus subject areas

  • Biochemistry

Cite this

Inactivation and self-association of Ca2+/calmodulin-dependent protein kinase II during autophosphorylation. / Hudmon, Andy; Aronowski, Jaroslaw; Kolb, Stephen J.; Waxham, M. Neal.

In: Journal of Biological Chemistry, Vol. 271, No. 15, 12.04.1996, p. 8800-8808.

Research output: Contribution to journalArticle

Hudmon, Andy ; Aronowski, Jaroslaw ; Kolb, Stephen J. ; Waxham, M. Neal. / Inactivation and self-association of Ca2+/calmodulin-dependent protein kinase II during autophosphorylation. In: Journal of Biological Chemistry. 1996 ; Vol. 271, No. 15. pp. 8800-8808.
@article{efd52952f066460b9de0b581f9f7d61c,
title = "Inactivation and self-association of Ca2+/calmodulin-dependent protein kinase II during autophosphorylation",
abstract = "The time-dependent loss in enzyme activity associated with the autophosphorylation of Ca2+/calmodulin-dependent protein kinase II (CaM-kinase) was altered by both pH and ATP concentration. These parameters also influenced the extent to which soluble CaM-kinase undergoes self-association to form large aggregates of sedimentable enzyme. Specifically, autophosphorylation of CaM-kinase in 0.01 mM ATP at pH 6.5 resulted in the formation of sedimentable enzyme and a 70{\%} loss of enzyme activity. Under similar conditions at pH 7.5, the enzyme lost only 30{\%} of its activity, and no sedimentable enzyme was detected. In contrast to 0.01 mM ATP, autophosphorylation of CaM-kinase at pH 6.5 in 1 mM ATP did not result in a loss of activity or the production of sedimentable enzyme, even though the stoichiometry of autophosphorylation was comparable. Electron microscopy studies of CaM-kinase autophosphorylated at pH 6.5 in 0.01 mM ATP revealed particles 100-300 nm in diameter that clustered into branched complexes. Inactivation and self-association of CaM-kinase were influenced by the conditions of autophosphorylation in vitro, suggesting that both the catalytic and physical properties of the enzyme may be sensitive to fluctuations in ATP concentration and pH in vivo.",
author = "Andy Hudmon and Jaroslaw Aronowski and Kolb, {Stephen J.} and Waxham, {M. Neal}",
year = "1996",
month = "4",
day = "12",
language = "English (US)",
volume = "271",
pages = "8800--8808",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "15",

}

TY - JOUR

T1 - Inactivation and self-association of Ca2+/calmodulin-dependent protein kinase II during autophosphorylation

AU - Hudmon, Andy

AU - Aronowski, Jaroslaw

AU - Kolb, Stephen J.

AU - Waxham, M. Neal

PY - 1996/4/12

Y1 - 1996/4/12

N2 - The time-dependent loss in enzyme activity associated with the autophosphorylation of Ca2+/calmodulin-dependent protein kinase II (CaM-kinase) was altered by both pH and ATP concentration. These parameters also influenced the extent to which soluble CaM-kinase undergoes self-association to form large aggregates of sedimentable enzyme. Specifically, autophosphorylation of CaM-kinase in 0.01 mM ATP at pH 6.5 resulted in the formation of sedimentable enzyme and a 70% loss of enzyme activity. Under similar conditions at pH 7.5, the enzyme lost only 30% of its activity, and no sedimentable enzyme was detected. In contrast to 0.01 mM ATP, autophosphorylation of CaM-kinase at pH 6.5 in 1 mM ATP did not result in a loss of activity or the production of sedimentable enzyme, even though the stoichiometry of autophosphorylation was comparable. Electron microscopy studies of CaM-kinase autophosphorylated at pH 6.5 in 0.01 mM ATP revealed particles 100-300 nm in diameter that clustered into branched complexes. Inactivation and self-association of CaM-kinase were influenced by the conditions of autophosphorylation in vitro, suggesting that both the catalytic and physical properties of the enzyme may be sensitive to fluctuations in ATP concentration and pH in vivo.

AB - The time-dependent loss in enzyme activity associated with the autophosphorylation of Ca2+/calmodulin-dependent protein kinase II (CaM-kinase) was altered by both pH and ATP concentration. These parameters also influenced the extent to which soluble CaM-kinase undergoes self-association to form large aggregates of sedimentable enzyme. Specifically, autophosphorylation of CaM-kinase in 0.01 mM ATP at pH 6.5 resulted in the formation of sedimentable enzyme and a 70% loss of enzyme activity. Under similar conditions at pH 7.5, the enzyme lost only 30% of its activity, and no sedimentable enzyme was detected. In contrast to 0.01 mM ATP, autophosphorylation of CaM-kinase at pH 6.5 in 1 mM ATP did not result in a loss of activity or the production of sedimentable enzyme, even though the stoichiometry of autophosphorylation was comparable. Electron microscopy studies of CaM-kinase autophosphorylated at pH 6.5 in 0.01 mM ATP revealed particles 100-300 nm in diameter that clustered into branched complexes. Inactivation and self-association of CaM-kinase were influenced by the conditions of autophosphorylation in vitro, suggesting that both the catalytic and physical properties of the enzyme may be sensitive to fluctuations in ATP concentration and pH in vivo.

UR - http://www.scopus.com/inward/record.url?scp=0029882409&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0029882409&partnerID=8YFLogxK

M3 - Article

C2 - 8621518

AN - SCOPUS:0029882409

VL - 271

SP - 8800

EP - 8808

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 15

ER -