title: Cocaine- and amphetamine-regulated transcript (CART) peptide specific binding in pheochromocytoma cells PC12.
abstract: CART (cocaine- and amphetamine-regulated transcript) peptides have been studied for ten years. We report specific binding of 125I-CART(61-102) to the rat adrenal pheochromocytoma PC12 cell line, both intact cells and cell membranes. Saturation binding to intact plated cells resulted in Kd of 0.48+/-0.16 nM and Bmax of 2228+/-529 binding sites/cell. 125I-CART(61-102) was also bound to PC12 cells differentiated using nerve growth factor to the neuronal phenotype with non-specific binding below 20%, and Kd of 1.90+/-0.27 nM and Bmax of 11,194+/-261 binding sites/cell. In competitive binding experiments, CART(61-102), CART(55-102) and di-iodinated CART(61-102) were bound to PC12 cell membranes with Ki in low nM range; their affinity to intact non-differentiated and differentiated cells was in low 10(-8) M range. In order to prove that iodination did not eliminate the pharmacological properties of CART, we tested the biological activity of di-iodinated CART(61-102). It decreased food intake in in vivo feeding experiment on fasted mice in a dose of 1 microg/mouse to the same extent as CART(61-102) in a dose of 0.5 microg/mouse.
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
authors.forename: Lenka
authors.initials: L
authors.lastname: Maletínská
authors.forename: Jana
authors.initials: J
authors.lastname: Maixnerová
authors.forename: Resha
authors.initials: R
authors.lastname: Matysková
authors.forename: Renata
authors.initials: R
authors.lastname: Haugvicová
authors.forename: Eva
authors.initials: E
authors.lastname: Sloncová
authors.forename: Tomás
authors.initials: T
authors.lastname: Elbert
authors.forename: Jirina
authors.initials: J
authors.lastname: Slaninová
authors.forename: Blanka
authors.initials: B
authors.lastname: Zelezná
mesh_terms: D000310:Adrenal Gland Neoplasms; D000818:Animals; D001667:Binding, Competitive; D002454:Cell Differentiation / Q000187:drug effects; D002462:Cell Membrane / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects; D007456:Iodine Isotopes / Q000378:metabolism; D007457:Iodine Radioisotopes / Q000378:metabolism; D007700:Kinetics; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008954:Models, Biological; D020932:Nerve Growth Factor / Q000494:pharmacology; D009419:Nerve Tissue Proteins / Q000378:metabolism* / Q000494:pharmacology; D009474:Neurons / Q000378:metabolism* / Q000473:pathology; D016716:PC12 Cells; D010446:Peptide Fragments / Q000378:metabolism; D010641:Phenotype; D010673:Pheochromocytoma; D011485:Protein Binding; D051381:Rats; D013997:Time Factors; D000098882:Cocaine- and Amphetamine-Regulated Transcript Protein
chemical_list: D007456:Iodine Isotopes; D007457:Iodine Radioisotopes; D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; D000098882:Cocaine- and Amphetamine-Regulated Transcript Protein; C428723:cocaine- and amphetamine-regulated transcript protein (55-102); D020932:Nerve Growth Factor