Prolactin Ovine
Description
Reproductive Regulation
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Ovarian Granulosa Cells (GCs):
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Low Concentrations (4–20 ng/mL): Enhance cell viability, reduce oxidative stress, and upregulate antioxidant enzymes (e.g., superoxide dismutase) .
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High Concentrations (>500 ng/mL): Induce cytotoxicity, apoptosis, and oxidative stress via pathways like the pentose phosphate pathway and mitophagy .
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Modulates steroidogenesis by reducing estradiol (E2) and altering progesterone (P4) secretion .
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Immune and Metabolic Roles
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Acts as a cytokine, influencing immune cell proliferation and hematopoiesis .
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Regulates glucose metabolism and insulin secretion in pancreatic β-cells .
Cytotoxicity and Oxidative Stress
A study treating ovine GCs with varying prolactin concentrations revealed:
| PRL (ng/mL) | Cell Viability | ROS Levels | MDA (Oxidative Marker) |
|---|---|---|---|
| 4 | ↑ 15% | ↓ 20% | ↓ 18% |
| 500 | ↓ 30% | ↑ 45% | ↑ 40% |
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Mechanistic Insights:
Hormonal Interactions
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Suppresses gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH), disrupting ovulation .
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Inhibits follicular development at serum levels >500 ng/mL, correlating with reduced follicle counts in ewes .
Production and Purification
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Expression System: Recombinant production in E. coli ensures high purity (>98%) .
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Purification Methods:
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Storage: Lyophilized at -80°C with stability maintained for years; reconstitution in sterile H2O or NaHCO3 buffer .
Applications in Research
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In Vitro Models: Used to study ovarian apoptosis, steroidogenesis, and hyperprolactinemia-induced infertility .
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Drug Development: Serves as a reference protein for prolactin receptor antagonists (e.g., R129G mutant with enhanced inhibitory activity) .
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Comparative Studies: Contrasted with native PRL to elucidate species-specific effects on poultry and mammalian reproduction .
Clinical and Agricultural Relevance
Product Specs
The protein solution, at a concentration of 1mg/ml, was lyophilized with a sodium bicarbonate (NaHCO3) concentration ranging from 0.02% to 0.03%.
To reconstitute the lyophilized Prolactin, it is advised to dissolve it in sterile 18MΩ-cm H2O or 0.4% NaHCO3 solution, adjusted to a pH between 8 and 9. The initial reconstitution should result in a concentration of at least 100µg/ml, which can then be diluted further in other aqueous solutions as needed.
The purity is determined to be greater than 99.0% using the following methods:
(a) Gel filtration analysis.
(b) SDS-PAGE analysis.
Protein quantification is performed using UV spectroscopy at a wavelength of 280 nm. An absorbance value of 0.93 is utilized as the extinction coefficient for a 0.1% (1mg/ml) solution. This specific value is determined by analyzing protein sequences using the PC DNAman computer program.
The sequence of the first six N-terminal amino acids was determined and was found to be Ala-Thr-Pro-Val-Cys-Pro.
Product Science Overview
In ruminants, prolactin-related proteins (PRPs) are non-classical members of the prolactin/growth hormone family. These proteins have been identified in the placentas of bovine, caprine, murine, and rat species . In cattle, placental lactogen (PL) and thirteen types of placental PRPs have been reported . In goats, PL has been detected in the placenta, and two newly discovered PRPs were reported as PRL-related molecules .
Ovine prolactin, specifically, is a lactogenic hormone secreted by the adenohypophysis. Besides its major action on lactation, in some species, prolactin exerts effects on reproduction, maternal behavior, fat metabolism, immunomodulation, and osmoregulation . Prolactin has also been shown to have cytokine-like activities and important immunoregulatory functions .
Recombinant ovine prolactin is produced in Escherichia coli (E. coli) as a single, non-glycosylated polypeptide chain containing 199 amino acids and having a molecular mass of 23 kDa . The protein is purified using proprietary chromatographic techniques and is available as a sterile, lyophilized (freeze-dried) powder . The recombinant protein is fully biologically active, as evidenced by its ability to induce the proliferation of Nb2 cells .
Recombinant ovine prolactin is used primarily for laboratory research purposes. It is not intended for use as drugs, agricultural or pesticidal products, food additives, or household chemicals . The lyophilized protein is stable at room temperature for up to three weeks but should be stored desiccated below -18°C for long-term storage . Upon reconstitution, it should be stored at 4°C for short-term use and below -18°C for future use, with the addition of a carrier protein to prevent freeze-thaw cycles .
