Premium
Evidence of proteoglycan/proteoglycan interactions within aggregates
Author(s) -
Kahn Anthony,
Pottenger Lawrence A.,
Phillips Frank M.,
Viola Randall W.
Publication year - 1991
Publication title -
journal of orthopaedic research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.041
H-Index - 155
eISSN - 1554-527X
pISSN - 0736-0266
DOI - 10.1002/jor.1100090602
Subject(s) - proteoglycan , chemistry , microbiology and biotechnology , biophysics , biochemistry , biology , extracellular matrix
Nonaggregated proteoglycan monomers, digested fragments of the monomers, as well as link proteins have been shown to self‐associate. These associations have not been shown to occur on the aggregate. However, previous reports, using the Kleinschmidt technique of monolayer electron microscopy, have noted proteoglycan subunits on the aggregate that appear to interact, either as branched proteoglycans or as proteoglycan subunits that appear to share the same attachment site on the hyaluronic acid chain. Branching and shared attachments were noted in all aggregates analyzed in this study. Increasing the average space between proteoglycan subunits on the reconstituted aggregated resulted in a significant decrease in branched proteoglycans, indicating either a weak association occurring on the aggregate, or an artifact created by a three‐dimensional structure being reduced to a two‐dimensional monolayer image. The shared attachments were independent of both the presence of link proteins and changes in spacing between proteoglycans, suggesting a proteoglycan—proteoglycan interaction occurring before aggregation. The interactions were not influenced by proteoglycan concentration at the time of aggregation. Link proteins, however, did increase the number of proteoglycans on the aggregate that could be cross‐linked with a bifunctional reagent, suggesting that link proteins facilitate proteoglycan—proteoglycan interactions.