Immunochemical detection of the proteoglycans decorin
and biglycan in human gingival crevicular ¯uid from sites
of advanced periodontitis
*, G. Embery
, A.J. Smith
Department of Basic Dental Science, Dental School, Heath Park, Cardi, CF4 4XY, UK
Department of Adult Dental Care, University of Glasgow Dental School, Glasgow, G2 3JZ, UK
Accepted 21 October 1997
This study characterized proteoglycan metabolites present in gingival crevicular ¯uid (GCF) collected from sites
with clinical evidence of advanced periodontal disease. The metabolites were puri®ed by anion-exchange
chromatography from which a chondroitin sulphate rich fraction was identi®ed by cellulose acetate electrophoresis.
Sodium dodecylsulphate±polyacrylamide gel electrophoresis of this fraction revealed a broad silver-staining band
with mol. wt 55±65 k and Western blotting suggested that this band was immunoreactive with CS-56, a monoclonal
antibody for chondroitin sulphate. Digestion of the metabolite with chondroitinase ABC (protease-free) led to the
loss of the silver-staining band. Dot-blot analysis identi®ed components in this fraction that were immunoreactive
for the monoclonal/polyclonal antibodies against the C-termino of decorin and biglycan. Amino acid analysis
revealed the composition of the proteoglycan metabolite to be rich in glycine, serine and glutamic acid.
Immunochemical and biochemical analyses were compared with those of proteoglycan puri®ed from human alveolar
bone. Changes in the amino acid composition were noted, suggesting the proteoglycan metabolite has undergone
extensive modi®cation and fragmentation to the protein core. The results suggest that the proteoglycan metabolite
from GCF represented a degradation product originating from the active destruction of the alveolar bone. They
provide further support for the proposal that the appearance of proteoglycan metabolites in GCF is a biomarker for
active destruction of alveolar bone, the biochemical analysis of which provides important information on
mechanisms involved in the pathology of periodontal diseases. # 1998 Elsevier Science Ltd. All rights reserved.
Keywords: Proteoglycan; Chondroitin sulphate; Gingival crevicular ¯uid; Biomarkers; Advanced periodontal disease
Periodontal diseases are now recognized as in¯amma-
tory conditions in response to bacterial antigens, which
lead to the breakdown of the supporting periodontal
tissues. The extracellular matrix of the periodontal
connective tissues, in common with that of other con-
nective tissues, is composed of a collagenous ®brous
network embedded in a complex extracellular matrix
composed of proteoglycans, hyaluronan and other
The proteoglycans present in the extracellular matrix
of the various periodontal tissues are important struc-
tural, non-collagenous components that consist of a
core protein attached to which are between 1 to 20 gly-
cosaminoglycan chains. A number of dierent proteo-
glycans have now been characterized in the
periodontal tissues, with a variety of functions ascribed
(Rahemtulla, 1992). Two of the most abundant proteo-
glycans identi®ed in the mineralized matrix of bone,
including alveolar bone, are decorin and biglycan,
Archives of Oral Biology 43 (1998) 287±295
0003-9969/98/$19.00 # 1998 Elsevier Science Ltd. All rights reserved.
* Corresponding author.
Abbreviations: SDS±PAGE, sodium dodecylsulphate±poly-
acrylamide gel electrophoresis.