Homooligomers constructed with 4- and 6-amino acid fragments of melanocortin (alpha-MSH) bind with higher affinity and with apparent cooperativity to melanocortin receptor, compared to their constituent monomers. Individual ligands were tethered with various spacers of different length and rigidity and the influence of spacers on binding was studied. Binding assays were performed on cells transfected with the melanocortin receptor, hMC4R. There is a 5-7-fold decrease in the EC(50) with the addition of each subunit, going from monomer to trimer. The Hill coefficient increases from 0.76 for the monomer to 1.12 for the dimer and 1.35 for the trimer. These data show a general trend of increasing avidity with increasing number of ligands in oligomers.
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http://dx.doi.org/10.1016/j.bmcl.2003.09.079 | DOI Listing |
Kidney Int
January 2025
Division of Nephrology, Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio, USA; Division of Kidney Disease and Hypertension, Rhode Island Hospital, the Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA. Electronic address:
Melanocortin therapeutics, exemplified by adrenocorticotropic hormone, have a proven steroidogenic-independent anti-proteinuric and glomerular protective effect. The biological functions of melanocortins are mediated by melanocortin receptors (MCR), including MC1R, which recent studies have shown to protect against glomerular disease. However, the role of other MCRs like MC5R is unknown.
View Article and Find Full Text PDFCurr Obes Rep
January 2025
Section on Growth and Obesity, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
Purpose Of Review: Hyperphagia is a condition associated with rare obesity-related diseases, presenting as a pathologic, insatiable hunger accompanied by abnormal food-seeking behaviors. In October 2023, a group of researchers and clinicians with expert knowledge on hyperphagia convened at the annual ObesityWeek meeting to discuss the need for a unified definition of hyperphagia and key items necessary to improve the identification, assessment, and treatment of hyperphagia in patients with melanocortin 4 receptor (MC4R) pathway-associated diseases.
Recent Findings: The definition of hyperphagia proposed by this group is a pathologic, insatiable hunger accompanied by abnormal food-seeking behaviors.
BMC Med Genomics
January 2025
Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences (TUMS), Tehran, Iran.
Background: The growth in obesity and rates of abdominal obesity in developing countries is due to the dietary transition, meaning a shift from traditional, fiber-rich diets to Westernized diets high in processed foods, sugars, and unhealthy fats. Environmental changes, such as improving the quality of dietary fat consumed, may be useful in preventing or mitigating the obesity or unhealthy obesity phenotype in individuals with a genetic predisposition, although this has not yet been confirmed. Therefore, in this study, we investigated how dietary fat quality indices with metabolically healthy obesity (MHO) or metabolically unhealthy obesity (MUO) based on the Karelis criterion interact with genetic susceptibility in Iranian female adults.
View Article and Find Full Text PDFBiochim Biophys Acta Mol Basis Dis
January 2025
National Forensic Sciences University, Gandhinagar 382007, Gujarat, India. Electronic address:
Cancer-associated cachexia (CAC) is a debilitating condition, observed in patients with advanced stages of cancer. It is marked by ongoing weight loss, weakness, and nutritional impairment. Lower tolerance of chemotherapeutic agents and radiation therapy makes it difficult to treat CAC.
View Article and Find Full Text PDFJ Med Chem
January 2025
Department of Medicinal Chemistry and the Institute for Translational Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455, United States.
The melanocortin receptors are a class of centrally and peripherally expressed G protein-coupled receptors, of which the MC3R and MC4R subtypes are implicated in the regulation of appetite and energy homeostasis and can serve as potential therapeutic targets for disorders such as obesity and cachexia. An unbiased high-throughput mixture-based library screen was implemented to identify novel ligands with an emphasis on the identification of nanomolar-potent agonists of the mouse melanocortin-3 receptor. This screen yielded the discovery of an N-branched tricyclic guanidine scaffold (TPI2408) that contained three nanomolar potent mMC3R agonists and additional compounds that possessed antagonism for the mMC4R.
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