title: Vertebrate (chick) collagen fibrils formed in vivo can exhibit a reversal in molecular polarity.
abstract: A reversal in molecular polarity can occur in vertebrate collagen fibrils. This has been demonstrated using a method for isolating, from chick embryo tendon, entire collagen fibrils 2 to 14 microns in length and suitable for electron-optical examination. A polarity reversal is present in some, but not all, of these fibrils. Such fibrils have two N-ends. The transition region, occupying several D-periods in which the reversal occurs, is not restricted to a central location in a fibril. Analysis of the fibril banding pattern through the transition region shows that the relative axial alignment of antiparallel molecules brings oppositely-directed C-telopeptides into axial register. This could allow antiparallel molecules to be covalently linked via polymeric cross-links involving these C-telopeptides.
authors.affiliation: Department of Medical Biophysics, University of Manchester, England.
authors.forename: D F
authors.initials: DF
authors.lastname: Holmes
authors.forename: M P
authors.initials: MP
authors.lastname: Lowe
authors.forename: J A
authors.initials: JA
authors.lastname: Chapman
mesh_terms: D000818:Animals; D002642:Chick Embryo; D002645:Chickens; D003094:Collagen / Q000737:chemistry / Q000648:ultrastructure*; D008854:Microscopy, Electron; D013710:Tendons / Q000737:chemistry; D014714:Vertebrates
chemical_list: D003094:Collagen