Structure-activity relationship of CART (cocaine- and amphetamine-regulated transcript) peptide fragments.
CART (cocaine- and amphetamine-regulated transcript) peptides are neuropeptides abundant in the central nervous system and periphery found to be involved in the regulation of food intake behavior and other physiological processes. Recently, we reported specific binding of (125)I-CART(61-102) to the rat adrenal pheochromocytoma cell line PC12, both intact cells and cell membranes. In this study, several fragments of CART(61-102) corresponding to its structural loops were synthesized and tested for their potency in binding experiments using PC12 intact cells and cell membranes and in feeding test with fasted mice. From all shorter peptides tested, only CART(74-86) and CART(62-86) containing disulfide bridges kept partial binding potency of the original molecule with K(i) in 10(-5) and 10(-4)M range. However, these fragments were not able to inhibit food intake after their central administration up to a dose of 4 nmol/mouse. The results showed that a compact structure containing three disulfide bridges is necessary for preservation of full biological activity of CART peptides.
Maixnerová
Jana
J
Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, 166 10 Prague 6, Czech Republic.
Hlavácek
Jan
J
Blokesová
Darja
D
Kowalczyk
Wioleta
W
Elbert
Tomás
T
Sanda
Miloslav
M
Blechová
Miroslava
M
Zelezná
Blanka
B
Slaninová
Jirina
J
Maletínská
Lenka
L
D000595:Amino Acid Sequence; D000818:Animals; D005247:Feeding Behavior / Q000187:drug effects; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000494:pharmacology*; D016716:PC12 Cells; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D013329:Structure-Activity Relationship; D000098882:Cocaine- and Amphetamine-Regulated Transcript Protein
D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; D000098882:Cocaine- and Amphetamine-Regulated Transcript Protein