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From Proteopedia
The insulin receptor ectodomain in complex with four venom hybrid insulins - symmetric conformation
Structural highlights
DiseaseINS_HUMAN Defects in INS are the cause of familial hyperproinsulinemia (FHPRI) [MIM:176730.[1] [2] [3] [4] Defects in INS are a cause of diabetes mellitus insulin-dependent type 2 (IDDM2) [MIM:125852. IDDM2 is a multifactorial disorder of glucose homeostasis that is characterized by susceptibility to ketoacidosis in the absence of insulin therapy. Clinical fetaures are polydipsia, polyphagia and polyuria which result from hyperglycemia-induced osmotic diuresis and secondary thirst. These derangements result in long-term complications that affect the eyes, kidneys, nerves, and blood vessels.[5] Defects in INS are a cause of diabetes mellitus permanent neonatal (PNDM) [MIM:606176. PNDM is a rare form of diabetes distinct from childhood-onset autoimmune diabetes mellitus type 1. It is characterized by insulin-requiring hyperglycemia that is diagnosed within the first months of life. Permanent neonatal diabetes requires lifelong therapy.[6] [7] Defects in INS are a cause of maturity-onset diabetes of the young type 10 (MODY10) [MIM:613370. MODY10 is a form of diabetes that is characterized by an autosomal dominant mode of inheritance, onset in childhood or early adulthood (usually before 25 years of age), a primary defect in insulin secretion and frequent insulin-independence at the beginning of the disease.[8] [9] [10] FunctionINS_HUMAN Insulin decreases blood glucose concentration. It increases cell permeability to monosaccharides, amino acids and fatty acids. It accelerates glycolysis, the pentose phosphate cycle, and glycogen synthesis in liver. Publication Abstract from PubMedCone snail venoms contain a wide variety of bioactive peptides, including insulin-like molecules with distinct structural features, binding modes and biochemical properties. Here, we report an active humanized cone snail venom insulin with an elongated A chain and a truncated B chain, and use cryo-electron microscopy (cryo-EM) and protein engineering to elucidate its interactions with the human insulin receptor (IR) ectodomain. We reveal how an extended A chain can compensate for deletion of B-chain residues, which are essential for activity of human insulin but also compromise therapeutic utility by delaying dissolution from the site of subcutaneous injection. This finding suggests approaches to developing improved therapeutic insulins. Curiously, the receptor displays a continuum of conformations from the symmetric state to a highly asymmetric low-abundance structure that displays coordination of a single humanized venom insulin using elements from both of the previously characterized site 1 and site 2 interactions. Symmetric and asymmetric receptor conformation continuum induced by a new insulin.,Xiong X, Blakely A, Kim JH, Menting JG, Schafer IB, Schubert HL, Agrawal R, Gutmann T, Delaine C, Zhang YW, Artik GO, Merriman A, Eckert D, Lawrence MC, Coskun U, Fisher SJ, Forbes BE, Safavi-Hemami H, Hill CP, Chou DH Nat Chem Biol. 2022 May;18(5):511-519. doi: 10.1038/s41589-022-00981-0. Epub 2022 , Mar 14. PMID:35289328[11] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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Categories: Homo sapiens | Large Structures | Agrawal R | Artik GO | Blakely AD | Chou DHC | Coskun U | Delaine C | Eckert D | Fisher SJ | Forbes BE | Gutmann T | Hill CP | Kim JH | Lawrence MC | Menting J | Merriman A | Safavi-Hemami H | Schafer IB | Schubert HL | Xiong X | Zhang Y
