Unfolded phosphopolypeptides enable soft and hard tissues to coexist in the same organism with relative ease

Curr Opin Struct Biol. 2013 Jun;23(3):420-5. doi: 10.1016/j.sbi.2013.02.010. Epub 2013 Apr 24.

Abstract

Unfolded phosphopolypeptides that contain one or more multiply phosphorylated short sequences can sequester amorphous calcium phosphate to form stable complexes of constant average size and chemical composition. A biofluid containing such complexes is supersaturated with respect to the bone and tooth mineral, hydroxyapatite but is undersaturated with respect to the amorphous precursor phase. Thus, soft tissues permeated by the biofluid should not experience ectopic calcification and hard tissues should remain mineralised. Sequestration by caseins allows high concentrations of calcium and phosphate to be attained in milk while osteopontin, fetuin and other phosphopolypeptides may act in a similar way in blood, other biofluids, soft and hard tissues.

Publication types

  • Review

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Body Fluids / chemistry
  • Calcification, Physiologic*
  • Calcium Phosphates / chemistry*
  • Calcium Phosphates / metabolism
  • Caseins / chemistry
  • Durapatite / chemistry
  • Durapatite / metabolism
  • Milk / chemistry*
  • Molecular Sequence Data
  • Phosphopeptides / chemistry*
  • Phosphopeptides / metabolism
  • Protein Folding
  • Proteins / chemistry*
  • Proteins / metabolism

Substances

  • Calcium Phosphates
  • Caseins
  • Phosphopeptides
  • Proteins
  • amorphous calcium phosphate
  • Durapatite