Design, Pharmacology, and NMR Structure of a Minimized Cystine Knot with Agouti-Related Protein Activity†

Biochemistry ◽  
2002 ◽  
Vol 41 (24) ◽  
pp. 7565-7572 ◽  
Author(s):  
Pilgrim J. Jackson ◽  
Joseph C. McNulty ◽  
Ying-Kui Yang ◽  
Darren A. Thompson ◽  
Biaoxin Chai ◽  
...  
Keyword(s):  
Nmr Structure ◽  
Related Protein ◽  
Protein Activity ◽  
Cystine Knot ◽  
Agouti Related Protein

High-Resolution NMR Structure of the Chemically-Synthesized Melanocortin Receptor Binding Domain AGRP(87−132) of the Agouti-Related Protein†,‡

Biochemistry ◽  
2001 ◽  
Vol 40 (51) ◽  
pp. 15520-15527 ◽  
Author(s):  
Joseph C. McNulty ◽  
Darren A. Thompson ◽  
Kimberly A. Bolin ◽  
Jill Wilken ◽  
Gregory S. Barsh ◽  
...  
Keyword(s):  
High Resolution ◽  
Receptor Binding ◽  
Binding Domain ◽  
Nmr Structure ◽  
Melanocortin Receptor ◽  
Receptor Binding Domain ◽  
Related Protein ◽  
High Resolution Nmr ◽  
Agouti Related Protein

scholarly journals NMR structure of a minimized human agouti related protein prepared by total chemical synthesis

FEBS Letters ◽  
1999 ◽  
Vol 451 (2) ◽  
pp. 125-131 ◽  
Author(s):  
Kimberly A. Bolin ◽  
D.Joe Anderson ◽  
Julie A. Trulson ◽  
Darren A. Thompson ◽  
Jill Wilken ◽  
...  
Keyword(s):  
Chemical Synthesis ◽  
Nmr Structure ◽  
Related Protein ◽  
Agouti Related Protein

scholarly journals I111n-Labeled Cystine-Knot Peptides Based on the Agouti-Related Protein for Targeting Tumor Angiogenesis

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Lei Jiang ◽  
Zheng Miao ◽  
Richard H. Kimura ◽  
Adam P. Silverman ◽  
Gang Ren ◽  
...  
Keyword(s):  
Tumor Angiogenesis ◽  
Cell Uptake ◽  
Mouse Serum ◽  
Tumor Uptake ◽  
Related Protein ◽  
Cystine Knot ◽  
Biodistribution Studies ◽  
Agouti Related Protein ◽  
Phosphate Buffered Saline

Agouti-related protein (AgRP) is a 4-kDa cystine-knot peptide of human origin with four disulfide bonds and four solvent-exposed loops. The cell adhesion receptor integrinαvβ3is an important tumor angiogenesis factor that determines the invasiveness and metastatic ability of many malignant tumors. AgRP mutants have been engineered to bind to integrinαvβ3with high affinity and specificity using directed evolution. Here, AgRP mutants 7C and 6E were radiolabeled with111In and evaluated forin vivotargeting of tumor integrinαvβ3receptors. AgRP peptides were conjugated to the metal chelator 1, 4, 7, 10-tetra-azacyclododecane- N,N′,N″,N‴-tetraacetic acid (DOTA) and radiolabeled with111In. The stability of the radiopeptides111In-DOTA-AgRP-7C and111In-DOTA-AgRP-6E was tested in phosphate-buffered saline (PBS) and mouse serum, respectively. Cell uptake assays of the radiolabeled peptides were performed in U87MG cell lines. Biodistribution studies were performed to evaluate thein vivoperformance of the two resulting probes using mice bearing integrin-expressing U87MG xenograft tumors. Both AgRP peptides were easily labeled with111In in high yield and radiochemical purity (>99%). The two probes exhibited high stability in phosphate-buffered saline and mouse serum. Compared with111In-DOTA-AgRP-6E,111In-DOTA-AgRP-7C showed increased U87MG tumor uptake and longer tumor retention (5.74±1.60and1.29±0.02%ID/g at 0.5 and 24 h, resp.), which was consistent with measurements of cell uptake. Moreover, the tumor uptake of111In-DOTA-AgRP-7C was specifically inhibited by coinjection with an excess of the integrin-binding peptidomimetic c(RGDyK). Thus,111In-DOTA-AgRP-7C is a promising probe for targeting integrinαvβ3positive tumors in living subjects.

scholarly journals Evaluation of a 64Cu-Labeled Cystine-Knot Peptide Based on Agouti-Related Protein for PET of Tumors Expressing  v 3 Integrin

2010 ◽  
Vol 51 (2) ◽  
pp. 251-258 ◽  
Author(s):  
L. Jiang ◽  
R. H. Kimura ◽  
Z. Miao ◽  
A. P. Silverman ◽  
G. Ren ◽  
...  
Keyword(s):  
Related Protein ◽  
Cystine Knot ◽  
Agouti Related Protein

scholarly journals A possible role of neuropeptide Y, agouti-related protein and leptin receptor isoforms in hypothalamic programming by perinatal feeding in the rat

Diabetologia ◽  
2004 ◽  
Vol 48 (1) ◽  
pp. 140-148 ◽  
Author(s):  
M. L�pez ◽  
L. M. Seoane ◽  
S. Tovar ◽  
M. C. Garc�a ◽  
R. Nogueiras ◽  
...  
Keyword(s):  
Neuropeptide Y ◽  
Leptin Receptor ◽  
Related Protein ◽  
Receptor Isoforms ◽  
Agouti Related Protein

Elongation studies of the human agouti-related protein (AGRP) core decapeptide (Yc[CRFFNAFC]Y) results in antagonism at the mouse melanocortin-3 receptor

Peptides ◽  
2003 ◽  
Vol 24 (2) ◽  
pp. 263-270 ◽  
Author(s):  
Christine G Joseph ◽  
Rayna M Bauzo ◽  
Zhimin Xiang ◽  
Amanda M Shaw ◽  
William J Millard ◽  
...  
Keyword(s):  
Related Protein ◽  
Agouti Related Protein

scholarly journals Neither Agouti-Related Protein nor Neuropeptide Y Is Critically Required for the Regulation of Energy Homeostasis in Mice

2002 ◽  
Vol 22 (14) ◽  
pp. 5027-5035 ◽  
Author(s):  
Su Qian ◽  
Howard Chen ◽  
Drew Weingarth ◽  
Myrna E. Trumbauer ◽  
Dawn E. Novi ◽  
...  
Keyword(s):  
Body Weight ◽  
Neuropeptide Y ◽  
Energy Homeostasis ◽  
Arcuate Nucleus ◽  
Body Weight Gain ◽  
Physiological Role ◽  
Related Protein ◽  
Double Knockout ◽  
Orexigenic Peptide ◽  
Agouti Related Protein

ABSTRACT Agouti-related protein (AgRP), a neuropeptide abundantly expressed in the arcuate nucleus of the hypothalamus, potently stimulates feeding and body weight gain in rodents. AgRP is believed to exert its effects through the blockade of signaling by α-melanocyte-stimulating hormone at central nervous system (CNS) melanocortin-3 receptor (Mc3r) and Mc4r. We generated AgRP-deficient (Agrp−/− ) mice to examine the physiological role of AgRP. Agrp−/− mice are viable and exhibit normal locomotor activity, growth rates, body composition, and food intake. Additionally, Agrp−/− mice display normal responses to starvation, diet-induced obesity, and the administration of exogenous leptin or neuropeptide Y (NPY). In situ hybridization failed to detect altered CNS expression levels for proopiomelanocortin, Mc3r, Mc4r, or NPY mRNAs in Agrp−/− mice. As AgRP and the orexigenic peptide NPY are coexpressed in neurons of the arcuate nucleus, we generated AgRP and NPY double-knockout (Agrp−/− ;Npy−/− ) mice to determine whether NPY or AgRP plays a compensatory role in Agrp−/− or NPY-deficient (Npy−/− ) mice, respectively. Similarly to mice deficient in either AgRP or NPY, Agrp−/− ;Npy−/− mice suffer no obvious feeding or body weight deficits and maintain a normal response to starvation. Our results demonstrate that neither AgRP nor NPY is a critically required orexigenic factor, suggesting that other pathways capable of regulating energy homeostasis can compensate for the loss of both AgRP and NPY.

scholarly journals Agouti-related protein (83-132) is a competitive antagonist at the human melanocortin-4 receptor: no evidence for differential interactions with pro-opiomelanocortin-derived ligands

2004 ◽  
Vol 180 (1) ◽  
pp. 183-191 ◽  
Author(s):  
LE Pritchard ◽  
D Armstrong ◽  
N Davies ◽  
RL Oliver ◽  
CA Schmitz ◽  
...  
Keyword(s):  
Energy Homeostasis ◽  
Intracellular Camp ◽  
Related Protein ◽  
Dissociation Kinetics ◽  
Competitive Antagonist ◽  
Melanocyte Stimulating Hormone ◽  
Natural Ligand ◽  
Melanocortin 4 Receptor ◽  
Significant Difference ◽  
Agouti Related Protein

Interactions between pro-opiomelanocortin (POMC)-derived peptides, agouti-related protein (AGRP) and the melanocortin-4 receptor (MC4-R) are central to energy homeostasis. In this study we have undertaken comprehensive pharmacological analysis of these interactions using a CHOK1 cell line stably transfected with human MC4-R. Our main objectives were (1) to compare the relative affinities and potencies of POMC-derived peptides endogenously secreted within the hypothalamus, (2) to investigate the potency of AGRP(83-132) antagonism with respect to each POMC-derived peptide and (3) to determine whether AGRP(83-132) and POMC-derived peptides act allosterically or orthosterically. We have found that beta melanocyte-stimulating hormone (betaMSH), desacetyl alpha MSH (da-alphaMSH) and adrenocorticotrophic hormone all have very similar affinities and potencies at the MC4-R compared with the presumed natural ligand, alphaMSH. Moreover, even MSH precursors, such as beta lipotrophic hormone, showed significant binding and functional activity. Therefore, many POMC-derived peptides could have important roles in appetite regulation and it seems unlikely that alphaMSH is the sole physiological ligand. We have shown that AGRP(83-132) acts as a competitive antagonist. There was no significant difference in the potency of inhibition by AGRP(83-132) or agouti(87-132) at the MC4-R, regardless of which POMC peptide was used as an agonist. Furthermore, we have found that AGRP(83-132) has no effect on the dissociation kinetics of radiolabelled Nle4,D-Phe7 MSH from the MC4-R, indicating an absence of allosteric effects. This provides strong pharmacological evidence that AGRP(83-132) acts orthosterically at the MC4-R to inhibit Gs-coupled accumulation of intracellular cAMP.

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