R-Phycoerytrhin IGFBP-4 antibody conjugate (IBP185)

Insulin-like growth factor binding protein-4 (IGFBP-4) is a secreted protein that is a member of the IGFBP family of proteins. It is expressed by a wide range of tissues and has been detected in most biological fluids. IGFBP-4 circulates in the plasma in a 28kD glycosylated and 24kD non-glycosylated form. It can bind to either IGF-I or IGF-II preventing the binding of these molecules to their receptors, and thereby modulating IGF-induced cell proliferation and differentiation. Pregnancy associated plasma protein A (PAPP-A) regulates the activity of IGFBP-4 by proteolysis and plays an important role in reproductive physiology. Studies also suggest that PAPP-A may be involved in the pathophysiology of acute coronary syndromes, promoting destabilization of the atherosclerotic plaque. Studies show that PAPP-A derived N- and C-terminal fragments of IGFBP-4 are released from unstable atherosclerotic plaques. These fragments may be novel biomarkers in the assessment of the risk of adverse cardiac events in patients with myocardial ischemia.