Abstract
The activity of protein kinase C (Ca2+/phospholipid-dependent enzyme) in the presence of phosphatidylserine and its physiological regulator, diacylglycerol, could be suppressed by a mixture of brain gangliosides. Half-maximal inhibition was observed at 30 microM and was nearly complete at 100 microM. Inhibition was observed at all concentrations of Ca2+ between 10(-8) and 10(-4) M. Inhibition of protein kinase C activity could not be reversed by increasing the concentration of diacylglycerol or the substrate, histone. Inhibition was also observed when myelin basic protein or a synthetic myelin basic protein peptide was used as substrate. Among the individual gangliosides, the rank order of potency was GT1b greater than GD1a = GD1b greater than GM3 = GM1. Our results suggest that gangliosides may regulate the responsiveness of protein kinase C to diacylglycerol.
Original language | English (US) |
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Pages (from-to) | 1633-1637 |
Number of pages | 5 |
Journal | Journal of Biological Chemistry |
Volume | 262 |
Issue number | 4 |
State | Published - Feb 5 1987 |
Externally published | Yes |
ASJC Scopus subject areas
- Biochemistry
- Molecular Biology
- Cell Biology