http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
biosynthesis, structure, and in vitro interaction of human decorin using the vaccinia virus/T7 bacteriophage system
Biosynthesis, structure, and in vitro interaction of human decorin using the vaccinia virus/T seven bacteriophage system
xii, 147 leaves : illustrations ; 28 cm.
Decorin is a small chondroitin sulfate proteoglycan found
ubiquitously in tissues. The biological function of decorin
is not well understood, although several studies have
suggested a role in regulating the deposition of the collagen
network, stabilizing the tissue architecture and modulating
cellular metabolism. Many of the biological assays used to
study the role of decorin and its interactions with other
matrix molecules, have used proteoglycans extracted from
tissues using denaturing solvents such as urea and guanidine
hydrochloride. These reagents may have irreversible effects
on protein structure, which could alter the binding potential
of proteoglycans with other matrix molecules. This study has
utilized the vaccinia virus/T7 bacteriophage expression
system to overexpress decorin glycoforms. Overexpression
resulted in secretion and purification under native
conditions of 30 mg decorin/109 cells per day. The decorin
protein expressed, comprised of subpopulations of
differentially glycosylated forms of the protein. Far LTV
circular dichroism spectra of native decorin showed a minimum
at 218 nm, consistent with a secondary structure that is
predominantly B-sheet. Circular dichroism spectra of
recombinant decorin purified in chaotropic solvents and
tissue extracted decorin revealed a minimum of 205 nm
indicating a loss of secondary structure. In vitro binding
studies on recombinant decorin purified under native and
denaturing conditons with collagenous proteins suggested
there are structure dependent and independent domains that
mediate these interactions. A biophysical analysis of the
changes on the secondary conformation of decorin and a
structurally related proteoglycan, biglycan, suggest these
urea, and are unable to refold to their original conformation
upon the removal of urea. These data confirm the importance
of secondary structure to the function of decorin.
Issued also on microfiche from University Microfilms Inc.
Includes bibliographical references: pages 132-145.