Measurement of binding kinetics between PI3-K and phosphorylated IGF-1R using a surface plasmon resonance biosensor

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

4 Scopus Citations
View graph of relations

Author(s)

  • Xueling Li
  • Chi-Chun Fong
  • Minghui Huang
  • Huimin Cao
  • Jianlong Zhao

Related Research Unit(s)

Detail(s)

Original languageEnglish
Pages (from-to)253-260
Journal / PublicationMicrochimica Acta
Volume162
Issue number1-2
Publication statusPublished - Jul 2008

Abstract

Quantitative measurement of biochemical and biophysical parameters of molecular recognition events in signaling pathways is very important for understanding biological function. Binding of insulin-like growth factor-1 receptor (IGF-1R) with IGF-1 activates receptor tyrosine phosphorylation and triggers several signaling pathways including phosphatidylinositol-3 kinase (PI3-K)/AKT and extracellular signal-regulated protein kinase (ERK)/mitogen-activated protein kinase (MAPK) pathways. We have analyzed the interactions between PI3-K and IGF-1R with or without IGF-1 stimulation. The results demonstrate that p85 subunits of PI3-K bind to IGF-1R with IGF-1 stimulation in intact cells. The binding kinetics between PI3-K and IGF-1R with or without IGF-1 stimulation were obtained using surface plasmon resonance biosensor. The affinity constant of the PI3-K to phosphorylated IGF-1R was (2.27 ± 0.12) × 108 M-1, which was about 20 times higher than that of PI3-K to unphosphorylated IGF-1R. Moreover, the kinetic effects of Mg2+, ATP and two kinase inhibitors, genistein and quercetin, on the binding between PI3-K and phosphorylated IGF-1R were studied. The data showed that Mg2+ increased the binding affinity of PI3-K with IGF-1R about 2-fold, while genistein decreased the affinity constant 2.7-fold. On the other hand, ATP and quercetin had no significant effects on the affinity constant, although both k a and k d values were increased or decreased by ATP or quercetin, respectively. This study implicated that the PI3-K binding sites on IGF-IR may be different from its phosphorylation and catalytic sites. © 2007 Springer-Verlag.

Research Area(s)

  • Insulin-like growth factor-1 receptor (IGF-IR), Mg2+, ATP, genistein and quercetin, Phosphatidylinositol 3-kinase (PI3-K), Surface plasmon resonance biosensor

Citation Format(s)

Measurement of binding kinetics between PI3-K and phosphorylated IGF-1R using a surface plasmon resonance biosensor. / Li, Xueling; Fong, Chi-Chun; Huang, Minghui; Cao, Huimin; Zhao, Jianlong; Yang, Mengsu.

In: Microchimica Acta, Vol. 162, No. 1-2, 07.2008, p. 253-260.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review