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1a7f
From Proteopedia
INSULIN MUTANT B16 GLU, B24 GLY, DES-B30, NMR, 20 STRUCTURES
Structural highlights
Disease[INS_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] Function[INS_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 PubMedDespite years of effort to clarify the structural basis of insulin receptor binding no clear consensus has emerged. It is generally believed that insulin receptor binding is accompanied by some degree of conformational change in the carboxy-terminal of the insulin B-chain. In particular, while most substitutions for PheB24 lead to inactive species, glycine or D-amino acids are well tolerated in this position. Here we assess the conformation change by solving the solution structure of the biologically active (GluB16, GlyB24, desB30)-insulin mutant. The structure in aqueous solution at pH 8 reveals a subtle, albeit well-defined rearrangement of the C-terminal decapeptide involving a perturbation of the B20-23 turn, which allows the PheB25 residue to occupy the position normally taken up by PheB24 in native insulin. The new protein surface exposed rationalizes the receptor binding properties of a series of insulin analogs. We suggest that the structural switch is forced by the structure of the underlying core of species invariant residues and that an analogous rearrangement of the C-terminal of the B-chain occurs in native insulin on binding to its receptor. A structural switch in a mutant insulin exposes key residues for receptor binding.,Ludvigsen S, Olsen HB, Kaarsholm NC J Mol Biol. 1998 May 29;279(1):1-7. PMID:9636695[11] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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