Prolactin Human, PEG
Description
Analytical Validation and Production
PEGylated prolactin is purified via chromatographic techniques and lyophilized for research applications . Key analytical methods for prolactin isoforms include:
Table 1: PEG Precipitation Protocol for Prolactin Analysis
| Step | Details |
|---|---|
| PEG Solution | 25% PEG 6000 in NaCl 0.9% or distilled water |
| Mixing Ratio | 1:1 serum-to-PEG solution |
| Centrifugation | 3,500 rpm for 30 minutes |
| Post-PEG Analysis | Monomeric prolactin measured in supernatant; recovery calculated as: |
Biochemical Properties
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Prolactin Variants:
Reference Ranges for Prolactin Assays
PEG precipitation is critical for distinguishing bioactive monomeric prolactin from macroprolactin. Gender-specific reference intervals are assay-dependent:
Table 2: Reference Ranges for Total and Monomeric Prolactin
| Parameter | Male (mIU/L) | Female (mIU/L) |
|---|---|---|
| Total Prolactin | 58–419 | 63–561 |
| Monomeric Prolactin | 32–309 (post-PEG) | 39–422 (post-PEG) |
Challenges in Prolactin Measurement
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Inter-Method Variability:
Immunoassays show significant variability due to differential reactivity with prolactin isoforms (e.g., macroprolactin) . For example: -
Macroprolactin Interference:
Applications and Limitations
Product Specs
Prolactin, a neuroendocrine hormone primarily produced by the pituitary gland, is also synthesized in other tissues like the placenta, brain, and uterus. Its secretion is triggered by various stimuli such as eating, nursing, mating, estrogen treatment, and ovulation. Primarily, prolactin promotes and maintains lactation. Additionally, it plays a role in breast cancer development, reproductive function regulation, and immunoregulation.
Recombinant Human Prolactin, in its pegylated form, is produced in E. coli. It exists as a single, non-glycosylated polypeptide chain comprising 199 amino acids, with an additional Alanine at the N-terminal. With a molecular weight of approximately 39 kDa, Pegylated Prolactin is mono-pegylated. Notably, under non-denaturing conditions, it exhibits a behavior akin to a 220 kDa protein due to its enhanced hydrodynamic volume.
The purification of the Pegylated Prolactin protein is achieved through proprietary chromatographic techniques.
The protein was lyophilized from a solution concentrated at 1mg/ml, containing 0.02% NaHCO3.
For reconstitution of lyophilized Prolactin, sterile 0.4% NaHCO3 at pH 8.5 is recommended, with a minimum concentration of 100µg/ml. This solution can be further diluted into other aqueous solutions as needed.
While lyophilized Prolactin remains stable at room temperature for up to 3 weeks, storage in desiccated conditions below -18°C is recommended. Upon reconstitution, Prolactin should be stored at 4°C for 2-7 days. For long-term storage, freezing below -18°C is advised.
Adding a carrier protein (0.1% HSA or BSA) is recommended for extended storage.
Avoid repeated freeze-thaw cycles.
Gel filtration analysis confirms a purity exceeding 95.0%.
The biological functionality of Pegylated Human Prolactin was assessed in vitro. This involved inducing proliferation in Nb2 cells and Baf/3 cells, specifically those stably transfected with Human Prolactin receptors. While its activity is lower than that of human Prolactin in vitro, it is anticipated to exhibit higher in vivo activity due to its prolonged circulation time.
Product Science Overview
Prolactin is a polypeptide hormone primarily synthesized and secreted by specialized cells in the anterior pituitary gland. It plays a crucial role in lactation, reproductive functions, and various homeostatic processes in the body. The human prolactin cDNA is 914 nucleotides long and generates the prolactin prohormone of 227 amino acids. After cleavage of the 28 amino acid signal peptide, mature human prolactin consists of 199 amino acids .
Pegylation is the process of attaching polyethylene glycol (PEG) chains to a molecule, in this case, prolactin. This modification enhances the stability and solubility of the protein, reduces immunogenicity, and prolongs its half-life in the bloodstream. Pegylated human prolactin has been tested for its biological functionality in vitro by inducing the proliferation of Nb2 cells or Baf/3 cells stably transfected with human prolactin receptors .
Recombinant human prolactin is produced using genetic engineering techniques. The gene encoding human prolactin is inserted into a suitable expression system, such as Escherichia coli (E. coli), to produce the protein in large quantities. The recombinant protein is then purified using various chromatographic techniques to ensure high purity and correct folding .
Applications of prolactin pegylated (human recombinant) include its use as a potential therapeutic agent for conditions such as dopamine-resistant prolactinomas, breast cancer, prostate cancer, and ovarian cancer. It acts by inhibiting target prolactin receptors, thereby downregulating the proliferation of cells expressing these receptors .
