4fxl
From Proteopedia
Crystal structure of the D76N Beta-2 Microglobulin mutant
Structural highlights
DiseaseB2MG_HUMAN Defects in B2M are the cause of hypercatabolic hypoproteinemia (HYCATHYP) [MIM:241600. Affected individuals show marked reduction in serum concentrations of immunoglobulin and albumin, probably due to rapid degradation.[1] Note=Beta-2-microglobulin may adopt the fibrillar configuration of amyloid in certain pathologic states. The capacity to assemble into amyloid fibrils is concentration dependent. Persistently high beta(2)-microglobulin serum levels lead to amyloidosis in patients on long-term hemodialysis.[2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] FunctionB2MG_HUMAN Component of the class I major histocompatibility complex (MHC). Involved in the presentation of peptide antigens to the immune system. Publication Abstract from PubMedWe describe a kindred with slowly progressive gastrointestinal symptoms and autonomic neuropathy caused by autosomal dominant, hereditary systemic amyloidosis. The amyloid consists of Asp76Asn variant beta(2)-microglobulin. Unlike patients with dialysis-related amyloidosis caused by sustained high plasma concentrations of wild-type beta(2)-microglobulin, the affected members of this kindred had normal renal function and normal circulating beta(2)-microglobulin values. The Asp76Asn beta(2)-microglobulin variant was thermodynamically unstable and remarkably fibrillogenic in vitro under physiological conditions. Previous studies of beta(2)-microglobulin aggregation have not shown such amyloidogenicity for single-residue substitutions. Comprehensive biophysical characterization of the beta(2)-microglobulin variant, including its 1.40-A, three-dimensional structure, should allow further elucidation of fibrillogenesis and protein misfolding. Hereditary systemic amyloidosis due to Asp76Asn variant beta2-microglobulin.,Valleix S, Gillmore JD, Bridoux F, Mangione PP, Dogan A, Nedelec B, Boimard M, Touchard G, Goujon JM, Lacombe C, Lozeron P, Adams D, Lacroix C, Maisonobe T, Plante-Bordeneuve V, Vrana JA, Theis JD, Giorgetti S, Porcari R, Ricagno S, Bolognesi M, Stoppini M, Delpech M, Pepys MB, Hawkins PN, Bellotti V N Engl J Med. 2012 Jun 14;366(24):2276-83. PMID:22693999[15] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. Loading citation details.. Citations No citations found See AlsoReferences
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