Propofol activates and allosterically modulates recombinant protein kinase C epsilon

Area of Science:

• Biochemistry
• Pharmacology
• Molecular Biology

Background:

• Anesthetic-induced myocardial protection involves protein kinase C epsilon (PKC epsilon) activation.
• A critical step in PKC epsilon activation is autophosphorylation at serine 729.

Purpose of the Study:

• To investigate propofol's interaction with PKC epsilon.
• To elucidate the molecular mechanisms underlying propofol's effect on PKC epsilon.

Main Methods:

• Immunoblot analysis assessed autophosphorylation of PKC epsilon at serine 729.
• Enzyme-linked immunosorbant assay measured PKC epsilon activity.
• Fluorescence spectroscopy identified molecular interactions within the C1B subdomain.

Main Results:

• Propofol significantly increased serine 729 phosphorylated PKC epsilon and its catalytic activity.
• Propofol enhanced phorbol ester-induced PKC epsilon activation.
• Propofol and phorbol myristate acetate quenched PKC epsilon C1B subdomain fluorescence, indicating binding site interaction.

Conclusions:

• Propofol directly interacts with PKC epsilon, inducing autophosphorylation and activation.
• Propofol's interaction suggests allosteric modulation of PKC epsilon activity near the phorbol ester binding site.