title: The tissue form of type VII collagen is an antiparallel dimer.
abstract: We recently reported the partial characterization of a new human collagen termed Type VII. This molecule is distinctive among the collagen family in that it contains three identical subunit alpha chains within a triple helical domain 424 nm in length. The molecule contains three identical alpha chains which are genetically distinct from other known collagens. Previous studies indicate that a portion of the limited pepsin-solubilized molecules appears to exist as antiparallel dimers associated by disulfide bonds. In this report, we demonstrate that the major tissue form of Type VII collagen is a dimer, associated by disulfide bonds through a 60-nm overlap of the aminoterminal triple helical ends. Intermolecular disulfide bonds occur only within this overlap region. Interchain disulfide bonds exist in the carboxyl terminal 7% of the molecule and may exist within the overlap region as well. Disulfide bond-stabilized aggregates larger than dimers are not seen.
authors.forename: N P
authors.initials: NP
authors.lastname: Morris
authors.forename: D R
authors.initials: DR
authors.lastname: Keene
authors.forename: R W
authors.initials: RW
authors.lastname: Glanville
authors.forename: H
authors.initials: H
authors.lastname: Bentz
authors.forename: R E
authors.initials: RE
authors.lastname: Burgeson
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000650:Amnion / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D003094:Collagen / Q000032:analysis*; D003488:Cyanogen Bromide / Q000494:pharmacology; D004220:Disulfides / Q000032:analysis; D005260:Female; D006801:Humans; D046911:Macromolecular Substances; D008854:Microscopy, Electron; D008970:Molecular Weight; D010434:Pepsin A / Q000378:metabolism; D011247:Pregnancy
chemical_list: D000596:Amino Acids; D004220:Disulfides; D046911:Macromolecular Substances; D003094:Collagen; D010434:Pepsin A; D003488:Cyanogen Bromide