Alignment of fibrillin molecules in elastic microfibrils is defined by transglutaminase-derived cross-links.
Microfibrils were extracted from human amnion in the form of a beaded filament and analyzed for the presence of transglutaminase-derived cross-links using acrylonitrile derivatization. The cross-link structure was isolated from protease hydrolysates of beaded filaments and identified as a phenylthiocarbamyl amino acid derivative by comparison to a standard. Acid hydrolysis of the isolated cross-link gave the expected lysine and glutamic acid in a 1:1 ratio. The beaded filaments were also treated with trypsin to produce a fraction that contained the bead structure and a fraction containing fragments of the interbead filaments. Cross-links were detected in the interbead filaments but not in the beads. A large tryptic peptide that contained a cross-link was isolated and sequenced. The two amino acid sequences obtained identified both of the cross-linked molecules as fibrillin-1 and enabled the approximate localization of the cross-link sites within the molecule. The locations of cross-link sites on two adjacent molecules fixed the relative positions of fibrillin monomers within the microfibrils, providing insight into the spatial organization of fibrillin within the elastic microfibrils.
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Shriners Hospital for Children, 3101 SW Sam Jackson Park Road, Portland, Oregon 97201, USA.
Glanville
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D000181:Acrylonitrile; D008841:Actin Cytoskeleton / Q000737:chemistry* / Q000648:ultrastructure; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000650:Amnion / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D003432:Cross-Linking Reagents; D019075:Electrophoresis, Capillary; D000071838:Fibrillin-1; D000071837:Fibrillins; D018698:Glutamic Acid / Q000032:analysis; D006801:Humans; D008239:Lysine / Q000032:analysis; D008840:Microfilament Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000648:ultrastructure; D008854:Microscopy, Electron; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D017421:Sequence Analysis; D011503:Transglutaminases / Q000378:metabolism*; D014357:Trypsin / Q000378:metabolism; D054392:Adipokines
D000181:Acrylonitrile; D000596:Amino Acids; D003432:Cross-Linking Reagents; D000071838:Fibrillin-1; D000071837:Fibrillins; D018698:Glutamic Acid; D008239:Lysine; D008840:Microfilament Proteins; D010446:Peptide Fragments; D011503:Transglutaminases; D014357:Trypsin; C000605722:FBN1 protein, human; D054392:Adipokines