GTP stabilization of adenylate cyclase activated and ADP-ribosylated by choleragen |
| |
Authors: | Seishi Nakaya Paul A Watkins Alan J Bitonti Leonard M Hjelmeland Joel Moss Martha Vaughan |
| |
Institution: | 2. Laboratory of Cellular Metabolism, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20205 USA;3. the Developmental Pharmacology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20205 USA |
| |
Abstract: | Choleragen activates adenylate cyclase in human skin fibroblasts by catalyzing the ADP-ribosylation of the 42,000 and 47,000 dalton guanyl nucleotide-binding regulatory components (G) of adenylate cyclase. The ADP-ribose linkage to 42,000 and 47,000 dalton proteins was stable at 30°C for 1 h with or without GTP, whereas GTP was required to stabilize activity of the G proteins. In human erythrocytes, choleragen catalyzed the ADP-ribosylation of only a 42,000 dalton G. The ADP-ribosyl-protein linkage was stable for 1 h at 30°C whether or not GTP was present, despite a rapid loss of G activity in the absence of GTP. Inactivation of choleragen-activated G in both the human fibroblast and human erythrocyte is, therefore, not secondary to the de-ADP-ribosylation of specifically labeled G subunits. |
| |
Keywords: | CD circular dichroism RR resonance Raman DTC diethyldithiocarbamate PL peroxidized lecithin |
本文献已被 ScienceDirect 等数据库收录! |
|