What is the Origin of IGFBP?

The term is a descriptive biochemical acronym. "IGF" stands for Insulin-like Growth Factor, and "BP" for Binding Protein. The discovery of these proteins followed the identification of IGFs, as researchers realized that the majority of circulating IGF was tightly bound to carrier molecules, which fundamentally altered their half-life and tissue distribution. This realization shifted the focus from simple total hormone concentration to the complex regulatory role of their binding partners.

What is the Mechanism of IGFBP?

The mechanism of action is multifaceted. IGFBPs primarily function by sequestering IGF-1, significantly extending its half-life from minutes to hours. Crucially, they also act as an inhibitory buffer, preventing IGF-1 from immediately binding to its high-affinity receptor on target cells. However, certain IGFBPs can also enhance IGF-1 action by concentrating it near the cell surface or by binding to their own unique receptors, triggering IGF-independent cellular signals. The local proteolytic cleavage of IGFBPs is the final regulatory step, which releases free, active IGF-1 to initiate its anabolic and mitogenic effects.

IGFBP

Meaning

IGFBP is the acronym for Insulin-like Growth Factor Binding Proteins, a family of six distinct proteins (IGFBP-1 through IGFBP-6) that serve as the primary carriers for Insulin-like Growth Factor 1 (IGF-1) and IGF-2 in the circulation and extracellular fluid. These proteins are crucial regulators of IGF bioavailability and action, preventing rapid degradation and modulating their access to target cell receptors. Clinically, the specific profile and concentration of different IGFBPs can be more informative than total IGF-1 levels alone, reflecting the true biological activity of the growth factors.