Binding of Escherichia coli heat-stable enterotoxin and rise of cyclic GMP in COLO 205 human colonic carcinoma cells.
Escherichia coli heat-stable enterotoxin (STa) was found to bind on the surface of human colonic (COLO 205) cells. The binding of [125I]STa to cell membranes was found to be specific, reversible and saturable. Scatchard analysis of the equilibrium binding demonstrated a single class of binding sites with a Kd of 0.5 x 10(-10) M. Autoradiographic analysis of polyacrylamide gel electrophoresis revealed the specific incorporation of [125I]STa into a single STa binding protein with a molecular mass of 95 kDa. Following incubation of COLO 205 cells with STa, a rise of intracellular cGMP was also evident.
Bhattacharya
J
J
Division of Pathophysiology, National Institute of Cholera and Enteric Diseases, Calcutta, India.
Chaudhuri
A G
AG
Sinha
A K
AK
Samanta
A K
AK
Chakrabarti
M K
MK
D001427:Bacterial Toxins / Q000378:metabolism* / Q000633:toxicity; D001665:Binding Sites; D002352:Carrier Proteins / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D003106:Colon / Q000378:metabolism* / Q000382:microbiology*; D003110:Colonic Neoplasms / Q000378:metabolism; D006152:Cyclic GMP / Q000096:biosynthesis / Q000378:metabolism*; D003967:Diarrhea / Q000209:etiology; D004768:Enterotoxins / Q000378:metabolism* / Q000633:toxicity; D004926:Escherichia coli / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000209:etiology; D029968:Escherichia coli Proteins; D006162:Guanylate Cyclase / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D009363:Neoplasm Proteins / Q000378:metabolism; D000074261:Receptors, Enterotoxin; D050705:Receptors, Guanylate Cyclase-Coupled; D018000:Receptors, Peptide / Q000378:metabolism; D014407:Tumor Cells, Cultured
D001427:Bacterial Toxins; D002352:Carrier Proteins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D009363:Neoplasm Proteins; D018000:Receptors, Peptide; C034151:heat stable toxin (E coli); D006162:Guanylate Cyclase; D000074261:Receptors, Enterotoxin; D050705:Receptors, Guanylate Cyclase-Coupled; D006152:Cyclic GMP