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== Publication Abstract from PubMed == | == Publication Abstract from PubMed == | ||
Enzymes that act on multiple substrates are common in biology but pose unique challenges as therapeutic targets. The metalloprotease insulin-degrading enzyme (IDE) modulates blood glucose levels by cleaving insulin, a hormone that promotes glucose clearance. However, IDE also degrades glucagon, a hormone that elevates glucose levels and opposes the effect of insulin. IDE inhibitors to treat diabetes, therefore, should prevent IDE-mediated insulin degradation, but not glucagon degradation, in contrast with traditional modes of enzyme inhibition. Using a high-throughput screen for non-active-site ligands, we discovered potent and highly specific small-molecule inhibitors that alter IDE's substrate selectivity. X-ray co-crystal structures, including an IDE-ligand-glucagon ternary complex, revealed substrate-dependent interactions that enable these inhibitors to potently block insulin binding while allowing glucagon cleavage, even at saturating inhibitor concentrations. These findings suggest a path for developing IDE-targeting therapeutics, and offer a blueprint for modulating other enzymes in a substrate-selective manner to unlock their therapeutic potential. | |||
Substrate-selective inhibitors that reprogram the activity of insulin-degrading enzyme.,Maianti JP, Tan GA, Vetere A, Welsh AJ, Wagner BK, Seeliger MA, Liu DR Nat Chem Biol. 2019 Jun;15(6):565-574. doi: 10.1038/s41589-019-0271-0. Epub 2019 , May 13. PMID:31086331<ref>PMID:31086331</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> |
Revision as of 09:32, 29 May 2019
Structure of Cysteine-free Human Insulin-Degrading Enzyme in complex with Glucagon and Substrate-selective Macrocyclic Inhibitor 63Structure of Cysteine-free Human Insulin-Degrading Enzyme in complex with Glucagon and Substrate-selective Macrocyclic Inhibitor 63
Structural highlights
Function[IDE_HUMAN] Plays a role in the cellular breakdown of insulin, IAPP, glucagon, bradykinin, kallidin and other peptides, and thereby plays a role in intercellular peptide signaling. Degrades amyloid formed by APP and IAPP. May play a role in the degradation and clearance of naturally secreted amyloid beta-protein by neurons and microglia.[1] [2] [3] [GLUC_HUMAN] Glucagon plays a key role in glucose metabolism and homeostasis. Regulates blood glucose by increasing gluconeogenesis and decreasing glycolysis. A counterregulatory hormone of insulin, raises plasma glucose levels in response to insulin-induced hypoglycemia. Plays an important role in initiating and maintaining hyperglycemic conditions in diabetes.[4] [5] [6] GLP-1 is a potent stimulator of glucose-dependent insulin release. Play important roles on gastric motility and the suppression of plasma glucagon levels. May be involved in the suppression of satiety and stimulation of glucose disposal in peripheral tissues, independent of the actions of insulin. Have growth-promoting activities on intestinal epithelium. May also regulate the hypothalamic pituitary axis (HPA) via effects on LH, TSH, CRH, oxytocin, and vasopressin secretion. Increases islet mass through stimulation of islet neogenesis and pancreatic beta cell proliferation. Inhibits beta cell apoptosis.[7] [8] [9] GLP-2 stimulates intestinal growth and up-regulates villus height in the small intestine, concomitant with increased crypt cell proliferation and decreased enterocyte apoptosis. The gastrointestinal tract, from the stomach to the colon is the principal target for GLP-2 action. Plays a key role in nutrient homeostasis, enhancing nutrient assimilation through enhanced gastrointestinal function, as well as increasing nutrient disposal. Stimulates intestinal glucose transport and decreases mucosal permeability.[10] [11] [12] Oxyntomodulin significantly reduces food intake. Inhibits gastric emptying in humans. Suppression of gastric emptying may lead to increased gastric distension, which may contribute to satiety by causing a sensation of fullness.[13] [14] [15] Glicentin may modulate gastric acid secretion and the gastro-pyloro-duodenal activity. May play an important role in intestinal mucosal growth in the early period of life.[16] [17] [18] Publication Abstract from PubMedEnzymes that act on multiple substrates are common in biology but pose unique challenges as therapeutic targets. The metalloprotease insulin-degrading enzyme (IDE) modulates blood glucose levels by cleaving insulin, a hormone that promotes glucose clearance. However, IDE also degrades glucagon, a hormone that elevates glucose levels and opposes the effect of insulin. IDE inhibitors to treat diabetes, therefore, should prevent IDE-mediated insulin degradation, but not glucagon degradation, in contrast with traditional modes of enzyme inhibition. Using a high-throughput screen for non-active-site ligands, we discovered potent and highly specific small-molecule inhibitors that alter IDE's substrate selectivity. X-ray co-crystal structures, including an IDE-ligand-glucagon ternary complex, revealed substrate-dependent interactions that enable these inhibitors to potently block insulin binding while allowing glucagon cleavage, even at saturating inhibitor concentrations. These findings suggest a path for developing IDE-targeting therapeutics, and offer a blueprint for modulating other enzymes in a substrate-selective manner to unlock their therapeutic potential. Substrate-selective inhibitors that reprogram the activity of insulin-degrading enzyme.,Maianti JP, Tan GA, Vetere A, Welsh AJ, Wagner BK, Seeliger MA, Liu DR Nat Chem Biol. 2019 Jun;15(6):565-574. doi: 10.1038/s41589-019-0271-0. Epub 2019 , May 13. PMID:31086331[19] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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