TPST2 Human
Description
Molecular Characterization of TPST2
Structure:
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Type II transmembrane protein (377 amino acids) with:
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Crystal structure (1.9 Å resolution) reveals:
Isoform Comparison:
| Feature | TPST1 | TPST2 |
|---|---|---|
| Amino Acid Residues | 370 | 377 |
| Sequence Identity | 64% | - |
| Substrate Specificity | Partially Overlapping | Broader Range |
Enzymatic Function and Mechanism
Catalytic Activity:
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Transfers sulfate from 3′-phosphoadenosine 5′-phosphosulfate (PAPS) to tyrosine residues in acidic motifs (e.g., D/E-Y-D/E)
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Requires intrinsically disordered regions near target tyrosine for substrate binding
Substrate Recognition:
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Binds peptides in a deep cleft via:
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Recognizes multiple tyrosine residues sequentially (e.g., CXCR4 and complement C4)
Key Substrates and Biological Roles
Pathophysiological Significance
Infectious Disease:
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TPST2-mediated sulfation of C5aR1 enables S. aureus leukocidins (HlgAB, PVL) to lyse phagocytes. Knockdown reduces cytotoxicity by 60–80% in vitro and improves survival in murine infection models .
Therapeutic Targeting:
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CRISPR-Cas9 knockout of TPST2 in phagocytes protects against S. aureus lethality without compromising C5aR1 expression .
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Potential for small-molecule inhibitors targeting the PAPS-binding pocket .
Recombinant Production and Research Tools
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Expression: Catalytically active TPST2 (41 kDa) produced in E. coli with N-terminal His-tag .
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Antibodies: Sheep anti-TPST2 polyclonal antibodies detect endogenous protein at 42 kDa in human pancreas lysates .
Evolutionary Context
Convergent evolution with receptor tyrosine kinases (e.g., insulin receptor kinase) in:
Product Specs
Product Science Overview
Tyrosylprotein Sulfotransferase 2 (TPST2) is an enzyme that catalyzes the O-sulfation of tyrosine residues within acidic regions of proteins. This post-translational modification is crucial for various biological processes, including protein-protein interactions, cell signaling, and immune responses . TPST2 is a type II integral membrane protein predominantly found in the Golgi apparatus .
Recombinant human TPST2 is typically produced using Chinese Hamster Ovary (CHO) cells. The protein is expressed with a C-terminal 6-His tag to facilitate purification . The preparation involves several steps:
- Gene Cloning: The TPST2 gene is cloned into an expression vector suitable for CHO cells.
- Transfection: The vector is introduced into CHO cells, which are then cultured under conditions that promote protein expression.
- Purification: The expressed protein is purified using affinity chromatography, exploiting the 6-His tag for binding to a nickel column .
- Validation: The purity and activity of the recombinant protein are validated using SDS-PAGE and enzyme activity assays .
TPST2 catalyzes the transfer of sulfate from 3’-phosphoadenylyl sulfate (PAPS) to tyrosine residues in target proteins. This reaction is essential for the function of various proteins involved in hemostasis, metabolism, and immune responses . The enzyme’s activity can be measured by its ability to sulfate specific peptide substrates, such as PSGL-1 .
Recent studies have highlighted the role of TPST2 in modulating immune responses. For instance, TPST2 has been shown to suppress interferon-γ signaling by sulfating the interferon-γ receptor 1, thereby influencing cancer immunity . Additionally, chemical synthesis of sulfated proteins has revealed that tyrosine sulfation enhances the inhibitory potency of thrombin-inhibiting proteins, underscoring the importance of this modification in anticoagulant activity .
