Mechanism of action of G protein-coupled receptors (GPCR) studied by LC-FTICR mass spectrometry
EMSL Project ID
2504
Abstract
Identify photoaffinity cross-links between G protein peptides and light-excited bovine rhodopsin using LC-FTICR mass spectrometry. The peptides stabilize the active conformation of light-excited rhodopsin and specifically compete with G protein for activation. Initial experiments on purified cross-linked peptides from CNBr-digested rhodopsin are estimated to require 7 days on the 7 tesla FTICR mass spectrometer. We have affinity purified the cross links and run MALDI and LC-MS iontrap but do not have the resolution to clearly identify the cross-linked products. We have been able to show a good yield of cross-links (5-10%) but need to know the locations of the cross-links on light-excited rhodopsin to better understand the mechanism of coupling of G proteins and GPCR--which are the largest superfamily of receptor systems in biology.
Project Details
Project type
Exploratory Research
Start Date
2002-04-22
End Date
2005-04-24
Status
Closed
Released Data Link
Team
Principal Investigator