Corticotropin-releasing hormone-binding protein and its possible role in neuroendocrinological research.

Corticotropin-releasing hormone-binding protein (CRH-BP), predominately produced by the liver, is a glycoprotein with a molecular weight of 37 kDa. The mature protein consists of 7 exons and 6 introns, with 5 tandem disulfide bridges which are essential for the binding of corticotropin-releasing hormone (CRH). This binding protein is distributed and expressed differently from corticotropin-releasing hormone receptors (CRH-Rs), as is the ligand requirement. Most CRH in plasma is bound to its binding protein, is therefore inactive and unable to bind to its receptor. Other competitives can reverse the binding, liberating CRH. Together with the CRH neuropeptides and CRH receptors, CRH-binding protein plays a role in the hypothalamic-pituitary-adrenal axis, in immune/inflammatory reactions as an auto/paracrine proinflammatory regulator, in pregnancy, as well as in some pathological conditions.