title: Elongational flow studies on type IV collagen: comparison with type I.
abstract: Elongation flow techniques have been used to investigate the birefringent response of monodisperse type IV collagen in dilute solution and the results compared with type I collagen. A four-roll mill apparatus was used to characterize the solutions at low strain rates, epsilon < or = 300 s-1. The birefringence is nonlocalized and rises gradually to a plateau value, in accordance with rigid-rod behavior. The gradients of the tangent to the curves at zero strain rate are estimated for types IV and I collagen. The concentrations of the solutions used were in the dilute to semidilute regimes. Using a value of 300 nm for the length of type I collagen, values of 364-408 nm were calculated for the length of the type IV collagen molecule, depending on the concentration regime chosen, which is consistent with biochemical predictions based on a rigid molecule. The results imply that the behavior of type IV collagen molecules in solution is similar to type I collagen, despite the presence of several sequence interruptions in the type IV helix.
authors.affiliation: Comparative Pathology Laboratory, School of Veterinary Science, University of Bristol, Langford, United Kingdom.
authors.forename: K
authors.initials: K
authors.lastname: Barnard
authors.forename: E D
authors.initials: ED
authors.lastname: Atkins
authors.forename: M A
authors.initials: MA
authors.lastname: Taylor
authors.forename: L J
authors.initials: LJ
authors.lastname: Gathercole
mesh_terms: D002627:Chemistry, Physical / Q000379:methods; D003094:Collagen / Q000737:chemistry*
chemical_list: D003094:Collagen