Prolactin Human, Antagonist
Greater than 95.0% as determined by gel filtration analysis.
Description
Prolactin Human Recombinant Antagonist des 1-9, G129R produced in E.Coli is a single, non-glycosylated polypeptide chain containing 190 amino acids + an additional Ala at n-terminal and having a molecular mass of ~ 22 kDa.
The Human Prolactin Antagonist is purified by proprietary chromatographic techniques.
Product Specs
The a.a. sequence of the 1st 6 N-terminal a.a. was found to be Ala-Arg-Ser-Gln-Val-Thr.
Product Science Overview
Prolactin is a hormone primarily associated with lactation in mammals. It is produced by the anterior pituitary gland and plays a crucial role in various physiological processes, including reproduction, metabolism, and immune regulation. However, excessive prolactin levels can lead to conditions such as prolactinomas, breast cancer, and other prolactin-related disorders. To counteract these effects, prolactin antagonists have been developed. One such antagonist is the human recombinant prolactin antagonist.
Human recombinant prolactin antagonists are engineered proteins designed to inhibit the action of prolactin by blocking its receptor. These antagonists are created by introducing specific mutations into the prolactin molecule, which prevent it from activating the prolactin receptor. For example, the Δ1-11-G129R-hPRL antagonist is a 21.9 kDa recombinant protein with 188 amino acids that downregulates the proliferation of cells expressing prolactin receptors .
The development of these antagonists involves molecular mimicry, where a bulky, negatively charged amino acid (such as glutamate or aspartate) is substituted for the normally phosphorylated serine in the prolactin molecule. This modification results in a molecule that can bind to the prolactin receptor without activating it, effectively blocking the receptor and preventing prolactin from exerting its effects .
The preparation of human recombinant prolactin antagonists typically involves the use of bacterial expression systems, such as Escherichia coli. The antagonist cDNA sequence is cloned into a plasmid vector, which is then introduced into the bacterial cells. The bacteria are cultured, and the recombinant protein is expressed and accumulated in the periplasmic space or inclusion bodies. The protein is then extracted and purified using chromatographic techniques, such as nickel-affinity chromatography and size-exclusion chromatography .
For instance, the Δ1-11-G129R-hPRL antagonist was synthesized by transforming E. coli BL21 (DE3) strain with a plasmid containing the antagonist cDNA sequence. The best expression conditions were achieved by activating at 35°C for 5 hours using 0.4 mM IPTG. The periplasmic fluid was extracted via osmotic shock, and the protein was purified to achieve over 95% purity .
Human recombinant prolactin antagonists have shown potential in various clinical applications. They are being investigated as potential treatments for dopamine-resistant prolactinomas, breast cancer, prostate cancer, and ovarian cancer, where autocrine prolactin acts as a growth-promoting agent. Additionally, these antagonists may have applications in pain relief and preventing hair loss .
The antagonistic effects of these proteins have been evaluated in vitro, demonstrating their ability to inhibit the proliferation of cancer cells overexpressing the prolactin receptor. This makes them promising candidates for targeted cancer therapies and other prolactin-related disorders .
