BONE MATRIX COLLAGEN ASSEMBLY--ROLE ON TYPE V COLLAGEN

Project: Research project

Description

The long term objective of the project is to understand the bone matrix
collagen assembly, specifically the role of type V collagen in bone
matrix. There is a growing body of evidence indicating that collagen-
collagen interactions may play an important role in controlling fiber
diameter and also in providing fibril network with reinforcement, thereby
specifying the mechanical properties of different tissues. Although a lot
of information has been gathered on type V collagen, its function in bone
or other tissues remains poorly understood. Three approaches will be explored for understanding the role of type V
collagen in bone matrix. The first will be to determine the potential of
type V collagen to copolymerize with type 1 collagen by analysis of the
nature of intermolecular cross-linking in bone type V collagen. Secondly,
to determine the role of the retained extension peptides on the tissue
form of type V collagen, and thirdly to assess the mode of type V collagen
degradation. All the intermolecular cross-linking sites in bone type V
collagen involving sodium borohydride reducible cross-links and also those
involving the mature 3-hydroxypyridinolines will be determined. The
reducible cross-links in type V collagen will be determined after reacting
the collagen with tritiated sodium borohydride to label the cross-linking
bonds. Cross-linked peptides involving 3-hydroxypyridinium residues in
type V collagen will be followed by their fluorescence, purified and
subjected to protein microsequencing analysis. The role of the extension
peptides retained on the tissue form of type V collagen will be assessed
by generating the extension peptides from the alpha chains by bacterial
collagenase digestion and then producing monospecific antibodies against
the extension peptides. The generated antibodies will then be used to
examine the role of these extension peptides in bone collagen fibrils.
The mode of type V collagen degradation by type V collagenase will be
determined by incubating native type V collagen with type V collagenase.
The initial sites of attack within the type V collagen will be determined
by aminoterminal sequence analysis of the generated fragments. Understanding the bone matrix collagen assembly may help to explain how
increased ratio of type V to type I collagen in osteogenesis imperfecta
patients may impair structural integrity of the bone tissue and contribute
to mechanical weakness.
StatusFinished
Effective start/end date3/1/942/29/00

Funding

  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health

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Collagen Type V
Bone Matrix
Collagen
Peptides
Bone and Bones
Collagenases
Collagen Type I
Antibodies
Sequence Analysis
Digestion