Identification of vitronectin as a major plasma protein adsorbed on polymer
surfaces of different copolymer composition
MD Bale, LA Wohlfahrt, DF Mosher, B Tomasini and RC Sutton
Life Sciences Research Laboratories, Eastman Kodak Company, Rochester, NY
14650-2113.
The arrays of proteins adsorbed from plasma onto a series of polystyrene
copolymeric latexes were analyzed by enzyme-linked immunosorbent assay
(ELISA) of washed beads and immunoblotting of proteins desorbed from the
beads and separated by polyacrylamide gel electrophoresis (PAGE). Beads
were prepared by continuous emulsion polymerization in the absence of
surfactant. Coomassie brilliant blue staining of gel electropherograms of
desorbed proteins indicated that the presence of small amounts of
comonomers (1 to 10 mole %) significantly influenced the composition of the
adsorbed protein layer. Immunoblotting revealed that fibrinogen,
fibronectin, and vitronectin were adsorbed by all surfaces investigated. C3
and Clq adsorption varied significantly with copolymer composition. The
ELISAs revealed that although the concentrations of vitronectin and
fibronectin in plasma are similar, the extent of vitronectin adsorption
from 70% to 85% plasma was greater by two orders of magnitude than
fibronectin adsorption. Vitronectin adsorbed on carboxylic acid-containing
copolymers reacted more strongly with a conformationally sensitive
antivitronectin monoclonal antibody (MoAb) than vitronectin adsorbed to
polystyrene and was more susceptible to cleavage by plasma proteases(s).
The results show that vitronectin is a major protein adsorbed from
concentrated plasma and that small changes in the chemical composition of a
copolymer profoundly affects the extent and nature of protein adsorption
from complex mixtures such as plasma.
Volume 74,
Issue 8,
pp. 2698-2706,
12/01/1989
Copyright © 1989 by The American Society of Hematology
