title: Viscoelastic properties and dynamics of porcine gastric mucin.
abstract: Gastric mucin is a glycoprotein known to undergo a pH-dependent sol-gel transition that is crucial to the protective function of the gastric mucus layer in mammalian stomachs. We present microscope-based dynamic light scattering data on porcine gastric mucin at pH 6 (solution) and pH 2 (gel) with and without the presence of tracer particles. The data provide a measurement of the microscale viscosity and the shear elastic modulus as well as an estimate of the mesh size of the gel formed at pH 2. We observe that the microscale viscosity in the gel is about 100-fold lower than its macroscopic viscosity, suggesting that large pores open up in the gel reducing frictional effects. The data presented here help to characterize physiologically relevant viscoelastic properties of an important biological macromolecule and may also serve to shed light on diffusive motion of small particles in the complex heterogeneous environment of a polymer gel network.
authors.affiliation: Department of Physics, Boston University, Boston, Massachusetts 02215, USA.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Celli
authors.forename: Brian
authors.initials: B
authors.lastname: Gregor
authors.forename: Bradley
authors.initials: B
authors.lastname: Turner
authors.forename: Nezam H
authors.initials: NH
authors.lastname: Afdhal
authors.forename: Rama
authors.initials: R
authors.lastname: Bansil
authors.forename: Shyamsunder
authors.initials: S
authors.lastname: Erramilli
mesh_terms: D000818:Animals; D004548:Elasticity; D005752:Gastric Mucins / Q000032:analysis* / Q000737:chemistry*; D013552:Swine; D013997:Time Factors; D014783:Viscosity
chemical_list: D005752:Gastric Mucins