GPI Recombinant Monoclonal Antibody
Description
Definition and Mechanism of GPI Recombinant Monoclonal Antibodies
GPI (glycosylphosphatidylinositol) recombinant monoclonal antibodies are engineered immune proteins designed to target GPI-anchored proteins, which are membrane-bound molecules linked to cellular surfaces via a GPI lipid anchor. These antibodies combine the specificity of monoclonal antibodies with recombinant DNA technology, enabling scalable production and reduced reliance on animal-derived antigens .
Key Features:
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Target Specificity: Bind to GPI-anchored proteins such as Thy-1 (CD90), TIMP-1-GPI, and GPIHBP1, which regulate cell adhesion, growth, and immune responses .
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Recombinant Production: Generated via mammalian cell systems (e.g., CHO cells) with GPI-anchor domains fused to purification tags (e.g., His-tag, Strep-tag) for streamlined isolation .
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Therapeutic Potential: Used in modulating MMP/TIMP balance, targeting lipid metabolism, and vaccine development .
Production Methods and Optimization
GPI recombinant antibodies are synthesized through engineered mammalian expression systems, often incorporating GPI-anchor domains for proper protein localization and function.
Purification Protocols:
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Antigen Affinity: Used for polyclonal antibodies (e.g., Proteintech’s 15171-1-AP) .
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Tag-Based: His-tag/Strep-tag chromatography for recombinant antibodies .
Applications in Research and Therapy
GPI recombinant antibodies serve diverse roles across biomedical fields, with validated applications in:
Therapeutic Interventions
Diagnostic and Research Tools
Conformational Dependency
GPI-anchor delipidation (e.g., via PI-PLC) induces structural changes, reducing antibody affinity. This affects:
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Soluble vs. Membrane-bound Thy-1: Antibodies like K117/5E10 fail to detect delipidated Thy-1 in immunoblots .
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Diagnostic Reliability: False negatives in fluid-based assays due to conformational instability .
Cross-Reactivity Risks
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Polyclonal Antibodies: Potential binding to non-GPI proteins (e.g., glucose phosphate isomerase) .
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Species Specificity: Limited reactivity (e.g., Biomatik’s CAC12210 targets human GPI only) .
TIMP-1-GPI in Mesothelial Cell Proliferation
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Dose-Dependent Effects: 14 ng/ml TIMP-1-GPI increased MMP-1/2/3/9 expression and enhanced wound closure in vitro .
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Cytokine Modulation: Reduced TNF-α and uPA secretion while elevating t-PA, suggesting anti-inflammatory and pro-healing roles .
GPIHBP1 Antibodies in Lipid Metabolism
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LPL Shuttling Blockade: Monoclonal antibodies disrupted LPL transport in endothelial cells, impacting triglyceride clearance .
GPI-Induced Arthritis Models
Product Specs
The GPI recombinant monoclonal antibody is produced using in vitro expression systems. This involves cloning DNA sequences encoding GPI antibodies obtained from immunoreactive rabbits. The immunogen used is a synthesized peptide derived from the human GPI protein. Subsequently, these GPI antibody-encoding genes are inserted into plasmid vectors and these recombinant vectors are transfected into host cells for antibody expression. Following expression, the GPI recombinant monoclonal antibody undergoes affinity chromatography purification and is rigorously tested for functionality in ELISA, WB, IHC, and FC applications. These tests demonstrate reactivity with the human GPI protein, confirming its efficacy.
Glucose-6-phosphate isomerase (GPI) plays a crucial role in glucose metabolism, particularly within the glycolytic pathway. GPI catalyzes the conversion of glucose-6-phosphate (G6P) to fructose-6-phosphate (F6P). This facilitates glucose breakdown for energy production and contributes to glucose homeostasis. Additionally, GPI participates in the pentose phosphate pathway, which is involved in nucleotide synthesis and redox balance.
Target Background
In the cytoplasm, GPI catalyzes the conversion of glucose-6-phosphate to fructose-6-phosphate, representing the second step in glycolysis. It also catalyzes the reverse reaction during gluconeogenesis. Beyond its role as a glycolytic enzyme, GPI also functions as a secreted cytokine, acting as an angiogenic factor (AMF) that stimulates endothelial cell motility. It functions as a neurotrophic factor, known as neuroleukin, for spinal and sensory neurons. Secreted by lectin-stimulated T-cells, it induces immunoglobulin secretion.
- A study revealed a novel pathway regulating hypoxia-induced angiogenesis in rheumatoid arthritis mediated by glucose-6-phosphate isomerase. PMID: 28067317
- Our research suggests that glucose-6-phosphate isomerase gene polymorphism may serve as potential biomarkers to predict the overall survival of hepatocellular carcinoma. PMID: 27288297
- The mutation p.Gln413Arg fs*24 is the first frameshift null mutation described in GPI deficiency. Molecular modeling suggests that the structural change induced by the p.Gly87Ala pathogenic variant directly impacts the structural arrangement of the region close to the active site of the enzyme. PMID: 27519939
- The two cysteines in hGPIc-c are prone to forming disulfides upon oxidation. hGPIc-c can induce arthritis in both B10.Q and B10Q.Ncf1*/* mice, whereas hGPIs-s immunization did not induce disease at all, demonstrating that these disulfides are crucial for the arthritis-inducing immune response. The cysteines at position 330 and 333 are not essential for TCR recognition. GILT expression affects hGPI-c-c processing at the CXXC motif. PMID: 29127146
- These results suggest that E4P, through direct interaction with extracellular HPI/AMF, may be an effective strategy to deter BCSC growth and progression. PMID: 28648642
- Silencing of PGI/AMF decreased the levels of phosphorylated Akt (-71.9%, P<0.001) compared to the scrambled siRNA, as well as the levels of the stemness marker, SOX2 (-61.7%, P<0.01). Collectively, these findings suggest that PGI/AMF silencing decreases migration, tumorsphere formation, and the proportion of on the side population cells in glioblastoma U87 cells. PMID: 26936801
- NLK is able to promote cell proliferation and type II collagen synthesis during in vitro chondrocyte propagation. PMID: 26573126
- Findings suggest that AMF/PGI-mediated tumorigenesis occurs through MAPK-ERK signaling in endometrial carcinoma. PMID: 26308071
- This study supports a role for AMF in mediating epithelial-mesenchymal transition in endometrial cancer (EC) through MAPK signaling. Therefore, AMF may serve as a potential prognostic and therapeutic target to prevent EC progression. PMID: 26201353
- Results showed an increase in GPI and AMFR in clear cell-renal cell carcinoma cells, and their colocalization on the plasma membrane. Kaplan-Meier curves revealed significant differences in survival among groups of patients with high versus low GPI expression. PMID: 26579829
- The association of ENO1 and GPI with postthaw sperm viability and motility was confirmed using Pearson's linear correlation. ENO1 and GPI can be used as markers of human sperm freezability before initiating the cryopreservation procedure. PMID: 25910678
- High GPI expression is associated with the metastatic phenotype of breast cancer. PMID: 24440856
- PGI is a moonlighting protein that functions as a cytosolic enzyme involved in glycolysis and gluconeogenesis, and as a cytokine through binding to its cell surface receptor. PMID: 11004567
- Serum anti-GPI autoantibodies are useful for diagnosing rheumatoid arthritis in Chinese patients. PMID: 23773638
- Findings suggest that autocrine motility factor (AMF)-HER2 interaction might be a novel target for therapeutic management of patients with breast cancer, whose disease is resistant to trastuzumab. PMID: 23248119
- For PGI, an extended active site is predicted, involving residues in the first, second, and third layers around the reacting substrate. PMID: 21970785
- GPI is a target gene of the BACH1 transcription factor, as determined by ChIP-seq analysis in HEK 293 cells. PMID: 21555518
- By regulating ER calcium release, AMF/PGI interaction with gp78/AMFR protects against ER stress, identifying novel roles for these cancer-associated proteins in promoting tumor cell survival. PMID: 21252914
- Data indicate that elevated serum glucose-6-phosphate isomerase may be involved in the synovitis of rheumatoid arthritis and could serve as a useful serum marker for disease activity. PMID: 20810510
- Data demonstrate effective downregulation of AMF/PGI expression and subsequent abrogation of AMF/PGI secretion, leading to morphological changes with reduced growth, motility, and invasion. PMID: 20978190
- The resistance of autocrine motility factor/phosphoglucose isomerase against TGF-beta-induced apoptosis was correlated with its enzymatic activity. PMID: 19819066
- Identified as a hypoxia-induced gene in pancreatic cancer cell lines. PMID: 11688991
- Overexpression induces neoplastic transformation and survival of NIH-3T3 fibroblasts. PMID: 12517804
- Results indicate that the enzymatic activity of PGI is not essential for either receptor binding or cytokine function of human PGI. PMID: 12527360
- Crystal structure and analysis of the initial ring-opening step of catalysis. PMID: 12573240
- Plays a role in regulating cell proliferation. PMID: 12783864
- AMF regulates the expression of Apaf-1 and caspase-9 genes via a complex signaling pathway and indirectly regulates the formation of the apoptosome (autocrine motility factor). PMID: 14566819
- Observations are consistent with a downstream mediation role of MMP-3 in Pohophoglucose isomerase/AMF-stimulated tumor cell metastasis. PMID: 14715248
- T-cell dependent peripheral polyarthritis induced by recombinant human glucose-6-phosphate isomerase in genetically unaltered mice demonstrates, for the first time, the induction of organ-specific disease by systemic autoimmunity. PMID: 15034067
- In addition to the findings in rheumatoid arthritis, our results indicate that GPI is not a general target of autoantibodies in juvenile idiopathic arthritis. PMID: 15290745
- Our findings suggest that GPI variants may play a crucial role in the production of autoantibodies against ubiquitous GPI autoantigens. PMID: 15369782
- AMF expression significantly contributes to the aggressive phenotype of pancreatic cancer. PMID: 15570012
- Phosphoglucose isomerase/autocrine motility factor activities are differentially regulated by protein kinase CK2 phosphorylation. PMID: 15637053
- Interaction with hypoxia-inducible factor-1 drives the mobility of erythroid progenitor cells. PMID: 15850830
- The N-glyco side-chain of AMFR is a trigger, and interaction between the 117-C-terminal part of AMF and the extracellular core protein of autocrine motility factor receptor (AMFR) is required during AMF-AMFR interactions. PMID: 16563432
- Elevated G6PI levels present in patients with immune-based inflammatory arthritis may contribute to elevated levels of anti-G6PI Abs and G6PI/anti-G6PI immune complexes. PMID: 16949042
- Missense mutations c.341A>T (p.Asp113Val) in exon 4 and c.663T>G (p.Asn220Lys) in exon 7 are associated with hereditary nonspherocytic hemolytic anemia. PMID: 17041899
- The receptor molecule for AMF/NLK/MF in leukemic differentiation is not gp78. PMID: 17071500
- Raft-dependent endocytosis of AMF follows a distinct phosphatidylinositol 3-kinase-dependent pathway that is up-regulated in more aggressive tumor cells. PMID: 17690101
- PGI/AMF is involved in oxidative stress-induced cellular senescence and should provide novel insights into the control of cellular growth, leading to new methodologies for cancer treatment. PMID: 17925402
- IL-6 and Th17 play an essential role in GPI-induced arthritis. PMID: 18311788
- Results of this study suggest that AMF stimulation stimulates MMP3 expression via a MAPK signaling pathway. PMID: 18485900
- Peptide fragment glucose phosphate isomerase (GPI)325-339 is identified as a major epitope in GPI-induced arthritis, with the potential to induce polyarthritis. PMID: 18992137
- Mutations affect the catalytic activity and structural stability of human glucose-6-phosphate isomerase. PMID: 19064002
- Expression of this protein leads to mesenchymal-to-epithelial transition in breast cancer cells. PMID: 19531650
- Overexpression of PGI significantly contributes to the aggressive phenotype of human colon cancer. PMID: 19787266
- Melanoma migration induced by AMF is mediated by autocrine production of IL-8 as a novel downstream modulator of the AMF signaling pathway. PMID: 19801670
