HSP27 Human, His
Description
Introduction to HSP27 Human, His
HSP27 Human, His refers to recombinant human heat shock protein 27 (HSP27), engineered with a histidine (His) affinity tag for purification and functional studies. Native HSP27, encoded by the HSPB1 gene, is a 23 kDa small heat shock protein (sHsp) critical for cytoprotection under stress. The recombinant form retains its biological activity while enabling precise biochemical assays and structural analyses. Its primary roles include chaperoning misfolded proteins, modulating apoptosis, and maintaining cytoskeletal integrity .
Domain Architecture
HSP27 comprises three key regions:
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N-terminal region (NTR): Mediates substrate binding and oligomerization.
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α-crystallin domain (ACD): A conserved β-sheet structure critical for dimerization and chaperone activity. Includes a unique cysteine residue enabling disulfide-linked dimers .
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C-terminal region (CTR): Regulates NTR-ACD interactions and solubility via polar residues and the Ile-Xxx-Ile/Val (IxI/V) motif .
Oligomerization Dynamics
HSP27 forms dynamic oligomers (500–800 kDa) through dimerization via the ACD. Phosphorylation (e.g., at Ser82) shifts equilibrium toward smaller oligomers, enhancing cytoprotective functions . Stress-induced phosphorylation by MAPKAP kinases modulates oligomer size and activity .
Cardiovascular Diseases
HSP27 expression is altered in atherosclerosis and ischemic heart disease (IHD):
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Atherosclerosis: HSP27 is downregulated in plaque cores but elevated in adjacent normal areas, suggesting a protective role against plaque progression .
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IHD: Serum HSP27 levels rise acutely after myocardial infarction but normalize within 12 hours. Higher anti-HSP27 antibody titers correlate with disease severity .
Cancer
HSP27 expression predicts prognosis:
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Breast cancer: Low HSP27 levels correlate with improved survival, particularly in estrogen receptor-negative subtypes .
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Melanoma: HSP27 knockdown induces tumor dormancy by suppressing VEGF-A and STAT3/NF-κB signaling .
Biomarker Potential
HSP27 serves as a biomarker in cardiovascular and metabolic disorders:
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Lower Extremity Arteriosclerosis (LEASO): Serum HSP27 inversely correlates with disease severity (e.g., Fontaine stages) and positively with ankle-brachial index (ABI) .
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Diabetes: Elevated HSP27 in diabetic nephropathy reflects renal oxidative stress and fibrosis .
| Disease | HSP27 Biomarker Trend | Associated Parameter |
|---|---|---|
| LEASO (Stage IV) | ↓ (25 ng/mL vs. 92 ng/mL Stage I) | ABI (0.06 vs. 0.85) |
| Diabetic Nephropathy | ↑ | Renal fibrosis |
Phosphorylation-Specific Roles
Phosphorylation at distinct serine residues (Ser15, Ser78, Ser82) modulates HSP27’s pro-survival vs. pro-inflammatory functions:
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Ser82 phosphorylation: Inhibits apoptosis by blocking cytochrome c/Apaf-1 complex formation .
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Ser78 phosphorylation: Enhances proteasome activation and NF-κB signaling .
Recombinant HSP27 Function
His-tagged HSP27 is widely used in:
Product Specs
Product Science Overview
Heat Shock Protein 27 (HSP27), also known as HSPB1, is a small chaperone protein that plays a crucial role in cellular stress responses. It is part of the small heat shock protein (sHsp) family, which includes other members like α-crystallin and Hsp20. HSP27 is involved in various cellular processes, including thermotolerance, inhibition of apoptosis, regulation of cell development, and differentiation .
HSP27 has a highly conserved α-crystallin domain near its C-terminus, which is essential for its chaperone activity. This domain consists of 80 to 100 amino acids that fold into β-sheets, forming stable dimers. The N-terminus contains a less conserved WD/EPF domain, followed by a short variable sequence. The C-terminal region is highly flexible and polar, contributing to the protein’s solubility and stability .
HSP27 forms large oligomers with an average mass of around 500 kDa in vitro. These oligomers consist of stable dimers formed by the α-crystallin domains of neighboring monomers. The N-terminus is essential for the development of these large oligomers .
HSP27 is overexpressed in various cellular stress states and is involved in regulating proteostasis by stabilizing protein conformation and promoting the refolding of misfolded proteins. It plays a significant role in protecting cells from multiple sources of stress injury, including oxidative stress, inflammatory responses, and apoptosis .
In addition to its intracellular functions, recent studies have shown that HSP27 can be found in the extracellular space, where it may signal via membrane receptors to alter gene transcription and cellular function .
HSP27 has been implicated in various disease states, including cardiovascular diseases, where it plays both protective and counter-protective roles. Targeting HSP27 is considered a promising strategy for the treatment of cardiovascular diseases due to its involvement in oxidative stress, inflammatory responses, and apoptosis .
Human recombinant HSP27 with a His tag is a form of the protein that has been genetically engineered to include a polyhistidine tag. This tag facilitates the purification of the protein using affinity chromatography techniques. The recombinant form retains the functional properties of the native protein and is used in various research applications to study its structure, function, and therapeutic potential.
