PRL R Human

Prolactin is a pituitary hormone that plays a crucial role in various physiological processes, including milk production, salt and water regulation, growth, development, and reproduction. The primary mechanism of prolactin’s action involves binding to a specific membrane receptor known as the prolactin receptor (PRLR), which belongs to the superfamily of class 1 cytokine receptors .

The prolactin receptor (PRLR) is a transmembrane protein that varies in size, ranging from approximately 40 kDa to 100 kDa, depending on the tissue source and species . The receptor consists of at least three distinct domains:

1. Extracellular Region: Contains five cysteines and the prolactin binding site.
2. Transmembrane Domain: A single domain that spans the cell membrane.
3. Cytoplasmic Region: The length of this region influences ligand binding and regulates cellular function .

The human recombinant prolactin soluble receptor (rHuPrl-R) is produced in Escherichia coli and is a non-glycosylated polypeptide chain containing 210 amino acids with a molecular mass of 23.97 kDa . This recombinant receptor is purified using proprietary chromatographic techniques and is typically provided as a sterile filtered white lyophilized powder .

The activity of the prolactin soluble receptor is determined by its dose-dependent inhibition of prolactin-stimulated proliferation of Nb2 cells and by its high-affinity binding to ovine prolactin and other lactogenic hormones in a 1:1 molar ratio . This receptor plays a significant role in various biological processes, including ion transport, osmoregulation, protein synthesis, and the regulation of numerous reproductive functions .

The lyophilized prolactin receptor is stable at room temperature for 1-2 weeks but should be stored desiccated below -18°C or preferably at -80°C to prevent dimer formation . Upon reconstitution, the receptor should be stored sterile at 4°C for 2-7 days and for long-term storage below -18°C . It is recommended to add a carrier protein (0.1% HSA or BSA) for long-term storage at 4°C . Freeze-thaw cycles should be avoided as they cause oligomerization of the protein .