Related Experiment Video

Updated: Jun 25, 2026

Highly Sensitive and Quantitative Detection of Proteins and Their Isoforms by Capillary Isoelectric Focusing Method
07:58

Highly Sensitive and Quantitative Detection of Proteins and Their Isoforms by Capillary Isoelectric Focusing Method

Published on: September 19, 2018

Functional and complementary phosphorylation state attributes of human insulin-like growth factor-binding protein-1

Mikkel Nissum1, Majida Abu Shehab, Ute Sukop

  • 1BD Diagnostics, Am Klopferspitz 19a, 82152 Planegg, Germany.

Molecular & Cellular Proteomics : MCP
|February 6, 2009
PubMed

Insights

High concentrations of insulin-like growth factor-binding protein-1 (IGFBP-1) are linked to fetal growth restriction (FGR). This study found that phosphorylation at Ser(119) significantly alters IGFBP-1

Area of Science:

  • Reproductive biology and endocrinology.
  • Biochemistry and molecular biology.
  • Perinatal medicine.

Background:

  • Fetal growth restriction (FGR) is a common pregnancy complication.
  • Elevated insulin-like growth factor-binding protein-1 (IGFBP-1) concentrations are associated with FGR.
  • Phosphorylation of IGFBP-1 influences insulin-like growth factor-I (IGF-I) bioavailability, a key factor in FGR.

Purpose of the Study:

  • To investigate the relationship between IGF-I affinity and IGFBP-1 phosphoisoform characteristics.
  • To identify specific phosphorylation sites on IGFBP-1 that modulate IGF-I binding.
  • To explore differences in IGFBP-1 phosphoisoform profiles between FGR and healthy pregnancies.

Main Methods:

  • Free flow electrophoresis (FFE) was used to separate IGFBP-1 phosphoisoforms from amniotic fluid.
  • BIAcore biosensor analysis determined IGF-I binding affinity (K(D)) for each phosphoisoform.
  • Liquid chromatography-tandem mass spectrometry (LC-MS/MS) identified and quantified phosphorylation sites.

Main Results:

  • Multiple IGFBP-1 phosphoisoforms were resolved, with IGF-I affinities ranging from 1.12e-08 to 4.59e-07.
  • Four phosphorylation sites were identified, including a novel site at Ser(98).
  • Phosphorylation at Ser(119) showed a significant association with IGF-I binding affinity, while other sites did not correlate.

Conclusions:

  • Phosphorylation at Ser(119) is a key mechanism modulating IGFBP-1's affinity for IGF-I.
  • Altered IGFBP-1 phosphoisoform profiles were observed in FGR pregnancies, suggesting site-specific phosphorylation changes.
  • This novel approach provides a basis for understanding IGFBP-1 phosphorylation in FGR and can be applied to other phosphoproteins.

More Related Videos

A High Resolution Method to Monitor Phosphorylation-dependent Activation of IRF311:44

A High Resolution Method to Monitor Phosphorylation-dependent Activation of IRF3

Published on: January 24, 2016

Identification of Inositol Phosphate or Phosphoinositide Interacting Proteins by Affinity Chromatography Coupled to Western Blot or Mass Spectrometry08:07

Identification of Inositol Phosphate or Phosphoinositide Interacting Proteins by Affinity Chromatography Coupled to Western Blot or Mass Spectrometry

Published on: July 26, 2019

Related Concept Videos

Phosphoinositides and PIPs01:42

Phosphoinositides and PIPs

Phosphoinositides are a group of phospholipids containing a glycerol backbone with two fatty acid chains and a phosphate attached to a myoinositol sugar ring. The inositol head group extends into the cytoplasm, where it is modified by adding phosphate groups to form phosphatidylinositol phosphates or PIPs.
Different phosphoinositides are synthesized and recruited on the cytosolic face of the plasma membrane. The localization of specific phosphoinositides concentrated in separate membrane...
Two-dimensional Gel Electrophoresis01:22

Two-dimensional Gel Electrophoresis

Two-dimensional gel electrophoresis is a high-resolution protein separation method first introduced by O' Farrell and Klose in 1975. This method involves protein separation by two dimensions, mass and charge, making it more accurate than one-dimensional gel electrophoresis.
The first dimension separation uses the isoelectric focusing or IEF technique performed on immobilized pH gradient (IPG) strips that separate proteins according to their isoelectric points.
Biological samples, such as  cells...
Protein and Protein Structure02:15

Protein and Protein Structure

Proteins are one of the most abundant organic molecules in living systems and have the most diverse range of functions of all macromolecules. Proteins may be structural, regulatory, contractile, or protective. They may serve in transport, storage, or membranes; or they may be toxins or enzymes. Their structures, like their functions, vary greatly. They are all, however, amino acid polymers arranged in a linear sequence.
A protein's shape is critical to its function. For example, an enzyme can...