GHBP Human, His
Description
Functional Role in GH Signaling
GHBP Human, His binds GH with high affinity, forming a 1:1 complex that regulates GH bioavailability and receptor interactions .
Key Mechanisms
-
Receptor Dimerization: GH binding induces dimerization of the growth hormone receptor (GHR), activating JAK2/STAT5 signaling .
-
Modulation of GH Half-Life: GHBP prolongs GH’s circulation by reducing its clearance rate .
-
Competitive Inhibition: High GHBP concentrations inhibit GH binding to GHR, acting as a regulatory feedback mechanism .
Binding Stoichiometry
| GH:GHBP Complex | Ratio | Function |
|---|---|---|
| 1:1 | Dominant | Transport and stabilization of GH |
| 1:2 | Rare | Antagonistic effects at high GHBP levels |
Diagnostic Utility
GHBP levels correlate with GHR expression and are used to assess growth disorders:
Isoform Variability
Exon 3 splicing generates two GHBP isoforms:
| Isoform | Exon 3 Status | Amino Acids | Function |
|---|---|---|---|
| E3+ | Included | 246 aa | Full-length extracellular domain |
| E3- | Excluded | ~230 aa | Truncated domain; unclear role |
Expression Systems
| System | Glycosylation | Molecular Weight | Key Features |
|---|---|---|---|
| Sf9 Insect Cells | Yes | 29.4 kDa | Native post-translational modifications |
| E. coli | No | 28.1 kDa | Lower cost but non-glycosylated |
Developmental Trends
GHBP levels rise sharply postnatally:
Correlation with Growth Metrics
Product Specs
VNETKWKMMD PILTTSVPVY SLKVDKEYEV RVRSKQRNSG NYGEFSEVLY VTLPQMSQFT CEEDFYLEHH HHHH.
Product Science Overview
GHBP is a glycoprotein that binds to GH with high affinity, preventing its degradation and prolonging its half-life in the bloodstream. This binding also regulates the amount of free GH available to interact with cell surface receptors, thereby modulating GH signaling pathways. The interaction between GH and GHBP is essential for maintaining proper growth and metabolic functions.
Recombinant GHBP is produced using various expression systems, including bacterial, yeast, insect, and mammalian cells. The human recombinant GHBP with a His tag is commonly expressed in Escherichia coli (E. coli) due to its simplicity and cost-effectiveness. The His tag, a sequence of histidine residues, is added to the protein to facilitate its purification using affinity chromatography techniques.
The production of recombinant GHBP involves several steps:
- Gene Cloning: The gene encoding the extracellular domain of the human GHR is cloned into an expression vector that includes a sequence for the His tag.
- Transformation: The expression vector is introduced into E. coli cells, which then produce the recombinant GHBP.
- Induction: The expression of GHBP is induced using specific chemicals, such as IPTG (isopropyl β-D-1-thiogalactopyranoside).
- Harvesting: The bacterial cells are harvested and lysed to release the recombinant protein.
- Purification: The His-tagged GHBP is purified using nickel affinity chromatography, which selectively binds to the His tag, allowing for the isolation of the recombinant protein.
Recombinant GHBP is used in various research and clinical applications, including:
- Studying GH Signaling: GHBP is used to investigate the mechanisms of GH signaling and its regulation.
- Therapeutic Development: GHBP can be used in the development of therapeutic agents for conditions related to GH deficiency or excess.
- Diagnostic Tools: GHBP is utilized in diagnostic assays to measure GH levels and assess GH-related disorders.
