Cirillo D, Naldini L, Moody T W, Comoglio P, Schlessinger J, Kris R
Rorer Biotechnology, Inc., King of Prussia, PA 19406.
Peptides. 1990 Jul-Aug;11(4):737-45. doi: 10.1016/0196-9781(90)90189-c.
Properties of detergent solubilized gastrin-releasing peptide receptor were investigated. Swiss 3T3 membranes were covalently labeled with [125I]GRP and homobifunctional cross-linkers. A major labeled protein of 75 kDa was resolved using SDS-polyacrylamide gel electrophoresis. When the same preparation was solubilized with zwitterionic detergent and analyzed under nondenaturing conditions the protein bound radioactivity was resolved in two different peaks, a major one of apparent molecular weight 220,000 (peak 1) and a minor one of 80,000 (peak 2) both containing the 75 kDa protein. Specific ligand binding activity also eluted with peak 1. These results indicate that the active form of bombesin/GRP receptor is a large complex containing the 75 kDa ligand binding domain.
