Related Experiment Video
Updated: Jul 6, 2026

A RAPID Method for Blood Processing to Increase the Yield of Plasma Peptide Levels in Human Blood
Published on: April 28, 2016
Regulation of ghrelin structure and membrane binding by phosphorylation
Eva Dehlin1, Jianhua Liu, Samuel H Yun
1Department of Anesthesiology, University of Virginia, Charlottesville, VA 22908, United States.
Abstract:
The peptide hormone ghrelin requires Ser-3 acylation for receptor binding, orexigenic and anti-inflammatory effects. Functions of desacylghrelin are less well understood. In vitro kinase assays reveal that the evolutionarily conserved Ser-18 in the basic C-terminus is an excellent substrate for protein kinase C. Circular dichroism reveals that desacylghrelin is approximately 12% helical in aqueous solution and approximately 50% helical in trifluoroethanol. Ser-18-phosphorylation, Ser-18-Ala substitution, or Ser-3-acylation reduces the helical character in trifluoroethanol to approximately 24%. Both ghrelin and desacylghrelin bind to phosphatidylcholine:phosphatidylserine sucrose-loaded vesicles in a phosphatidylserine-dependent manner. Phosphoghrelin and phosphodesacylghrelin show greatly diminished phosphatidylserine-dependent binding. These results are consistent with binding of ghrelin and desacylghrelin to acidic lipids via the basic face of an amphipathic helix with Ser-18 phosphorylation disrupting both helical character and membrane binding.
Related Concept Videos
GPCRs Regulate Adenylyl Cylase Activity
Two...
Regulation of Food Intake
Amplifying Signals via Enzymatic Cascade
Protein Kinases and Phosphatases
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Receptor Tyrosine Kinases
Receptor Downregulation in MVBs
The EGFR can initiate signaling pathways that lead to cell proliferation, migration, and differentiation. Overexpression of EGFR stimulates cells to proliferate. Excessive EGFR activation may...

