ABSTRACT
The affinity of a bone collagen alpha1 chain for hydroxyapatite has been compared to a similarly isolated skin component from the same animals. The chain from bone exhibits a higher affinity for the mineral. This enhanced affinity appears to be related to its primary structure, specifically its hydroxylysine moieties.
Subject(s)
Bone and Bones/metabolism , Collagen/metabolism , Hydroxyapatites/metabolism , Skin/metabolism , Age Factors , Aminopropionitrile , Animals , Chromatography , Hydroxylysine/metabolism , Lathyrism/chemically induced , Lathyrism/metabolism , Male , Methods , Rats , Structure-Activity RelationshipSubject(s)
Aspartic Acid/analysis , Dentin/analysis , Phosphoproteins/analysis , Amino Acid Sequence , Animals , CattleABSTRACT
Denatured collagen samples extracted from the skin and bone of lathyritic rats with guanidine hydrochloride were chromatographed on hydroxyapatite columns. A major fraction of the bone extract that was rich in alpha chain showed a stronger binding to hydroxyapatite when compared to the corresponding fraction from skin. Thus, bone collagen shows a special affinity for hydroxyapatite after isolation and denaturation.
Subject(s)
Bone and Bones , Collagen , Hydroxyapatites , Skin , Amino Acids/analysis , Animals , Binding Sites , Bone and Bones/analysis , Chemical Fractionation , Chromatography , Collagen/analysis , Electrophoresis, Polyacrylamide Gel , Lathyrism/metabolism , Rats , Skin/analysisABSTRACT
(Ethylenedinitrilo)tetraacetic acid soluble phosphoproteins were isolated from rat incisor and bovine unerupted teeth. This material was examined for its effect on the stability of amorphous calcium phosphate in vitro. When the precipitation of amorphous calcium phosphate was attempted in the presence of small amounts of these phospho-proteins, an apatite-like mineral was observed to form, which was approximately 60% crystalline, as determined by infrared measurements. This apatite phase could not be induced by addition of phosphoprotein after the precipitation reaction. The organic phosphate bound to these phosphoproteins was shown to be directly responsible for the formation of the apatite phase, since removal of 60% of the covalently bound phosphate with alkaline phosphatase destroyed the protein's ability to induce hydroxylapatite formation. The properties of the dental phosphoproteins appear to be consistent with their possible involvement in the development of the mineral phase of dentine.
