Isolation of a novel insulin-like growth factor (IGF) binding protein from human bone: a potential candidate for fixing IGF-II in human bone

Biochem Biophys Res Commun. 1991 Apr 30;176(2):756-63. doi: 10.1016/s0006-291x(05)80249-9.

Abstract

Insulin-like growth factor-II (IGF-II) is the most abundant growth factor stored in human bone. Upon release from this storage depot, IGF-II could act in bone repair and in the coupling of bone formation to bone resorption, a process inherent to bone which is a key regulatory process for maintenance of bone tissue. In this study, we report the isolation and characterization of a novel IGF binding protein (IGFBP) from human bone and describe how this IGFBP may be involved in the fixation of IGF-II in human bone. This new IGFBP has an apparent molecular weight of 29 kDa and has several fold higher affinity for IGF-II than IGF-I which could explain the much greater abundance of IGF-II than IGF-I in human bone. In terms of biological activity, this IGFBP was found to potentiate the proliferative actions of IGF-II on bone cells. This work raises the possibility that this IGFBP may participate in mediating some of the actions of IGF-II.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Binding, Competitive
  • Bone Development
  • Bone and Bones / chemistry
  • Bone and Bones / metabolism*
  • Carrier Proteins / metabolism*
  • Cell Division
  • Durapatite
  • Humans
  • Hydroxyapatites / metabolism*
  • Insulin-Like Growth Factor Binding Proteins
  • Insulin-Like Growth Factor II / metabolism*
  • Molecular Sequence Data
  • Molecular Weight
  • Somatomedins / metabolism

Substances

  • Carrier Proteins
  • Hydroxyapatites
  • Insulin-Like Growth Factor Binding Proteins
  • Somatomedins
  • Insulin-Like Growth Factor II
  • Durapatite