GO:0043924 suramin binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0043924 suramin binding is a molecular function describing the binding of the polysulfonated naphthylamine compound suramin to proteins, as defined by QuickGO.
• Suramin binds a wide range of targets including kinases, DNA-binding proteins, glycosaminoglycan-binding proteins, and cell-surface receptors [1,2,3,4,5,6,7,8].
• Suramin binding often occurs through electrostatic interactions with positively charged pockets or heparin-binding sites on proteins [1,2,4].
• This binding event can disrupt protein-protein interactions, nucleic acid binding, and receptor-ligand recognition, explaining suramin's broad biological effects [3,5,6,7,8].
• Key proteins reported to bind suramin include Raf1 kinase inhibitory protein, Mcm10, calmodulin, IL-4 receptor, HIV-1 gp120, and hepatitis C envelope proteins [1,3,4,5,7,8].
• Studying suramin binding informs drug repurposing, antiviral and antiparasitic strategies, and basic research on protein-ligand interactions [1,3,5,7].
Description
GO:0043924 suramin binding is a molecular function term in the Gene Ontology that describes the selective interaction of a protein or macromolecule with suramin, a naphthalenesulfonic acid compound historically used to treat trypanosomiasis and onchocerciasis [1,2,3,4,5,6,7,8]. Suramin is a polysulfonated molecule that binds to many proteins, often at sites that normally interact with polyanions such as heparin or nucleic acids [1,2,4]. Because suramin binding can modulate protein function, it has become a valuable tool in chemical biology and drug discovery [1,5]. Researchers study suramin binding to understand fundamental protein-ligand recognition and to explore therapeutic applications ranging from antiviral to anticancer strategies [3,5,7,8]. The term is particularly relevant for annotating proteins that interact with suramin or its analogues, and for interpreting high-throughput binding assays [1,2,5]. This article summarizes the current knowledge on suramin binding, its molecular mechanisms, key genes, and experimental approaches, based strictly on published literature.
suramin binding At A Glance
| GO ID | GO:0043924 |
|---|---|
| GO term | suramin binding |
| Ontology | molecular_function |
| Synonym | Germanin binding |
| Major function | Binding to suramin, a naphthalenesulfonic acid compound used against trypanosomes and worms |
| Definition source | QuickGO |
| Common targets | Kinases, DNA-binding proteins, glycosaminoglycan-binding proteins, cell-surface receptors |
| Biological impact | Modulation of protein-protein interactions, nucleic acid binding, and receptor signaling |
What Is GO:0043924?
According to the Gene Ontology, GO:0043924 suramin binding is defined as the binding to suramin, a naphthalenesulfonic acid compound which is used in the treatment of diseases caused by trypanosomes and worms. In practice, this means a protein or macromolecule can physically interact with suramin, often through electrostatic or hydrophobic contacts, leading to a measurable binding event [1,2,3,4,5,6,7,8]. The synonym Germanin binding is also used historically. This molecular function is distinct from suramin transport or suramin metabolism; it specifically denotes the binding interaction itself.
Why Is suramin binding Important in Cell Biology?
Suramin binding is important because suramin is a clinically approved drug with broad-spectrum activity, and its binding to diverse proteins underlies both its therapeutic effects and its side effects [1,2,3,4,5,6,7,8]. Understanding which proteins bind suramin and how this binding alters function can reveal new drug targets, guide repurposing efforts, and help design more selective analogues [1,5]. Moreover, suramin binding serves as a model for studying polyanion-protein interactions, which are relevant to many biological processes including viral entry, growth factor signaling, and DNA metabolism [2,3,5,7,8].
• Suramin binding to Raf1 kinase inhibitory protein (RKIP) targets a conserved ligand-binding pocket, offering insights into kinase regulation.
• Suramin and heparin impede binding of free adenine to a DNA glycosylase, linking suramin binding to DNA repair.
• Suramin blocks hepatitis C virus binding to hepatoma cells, highlighting its antiviral potential.
• Suramin and its analogue NF307 discriminate among calmodulin-binding sites, showing selectivity in binding.
• Suramin inhibits the DNA-binding protein Mcm10, affecting DNA replication.
• Suramin disrupts antibody binding to cell surface antigens and complement-mediated lysis, relevant to autoimmune conditions.
• Suramin blocks interleukin-4 binding to its receptors, modulating immune signaling.
• Suramin inhibits binding of HIV-1 gp120 V3 region to galactosylceramide, a receptor on colon epithelial cells.
• Suramin binding is a common mechanism for inhibiting protein-nucleic acid interactions [2,5].
• Studying suramin binding aids in the development of new antiparasitic, antiviral, and anticancer agents [1,3,5,7].
Molecular Mechanism of suramin binding
Electrostatic Interactions with Polyanion-Binding Pockets
In simple terms: Suramin sticks to proteins by attracting to positive charges.
Suramin is a highly sulfonated molecule, giving it a strong negative charge. Many proteins that bind suramin contain positively charged patches or pockets that normally interact with polyanions such as heparin or nucleic acids. For example, suramin targets the conserved ligand-binding pocket of human Raf1 kinase inhibitory protein, likely through electrostatic complementarity. Similarly, suramin and heparin impede binding of free adenine to a DNA glycosylase from C. pseudotuberculosis, suggesting competition for a polyanion-binding site. This electrostatic mechanism is a recurring theme in suramin binding.
Competition with Natural Ligands
In simple terms: Suramin can block other molecules from binding to the same protein.
Suramin often acts as a competitive inhibitor by occupying sites that normally bind biological ligands. For instance, suramin blocks hepatitis C binding to human hepatoma cells, likely by competing with viral envelope proteins for cell surface receptors. It also inhibits binding of interleukin-4 to its receptors on human tumor cells, preventing downstream mitogenic signaling. In another example, suramin inhibits binding of the V3 region of HIV-1 envelope glycoprotein gp120 to galactosylceramide, the receptor on human colon epithelial cells. These competitions explain many of suramin's biological effects.
Discrimination Among Binding Sites
In simple terms: Suramin can choose between similar binding sites on the same protein.
Suramin and its analogue NF307 discriminate among calmodulin-binding sites, indicating that suramin binding is not uniform and can exhibit selectivity even within a single protein. This suggests that the molecular details of the binding pocket, such as charge distribution and shape, determine whether suramin binds. Such discrimination is important for designing suramin-based inhibitors with fewer off-target effects.
Inhibition of DNA-Binding Proteins
In simple terms: Suramin can stop proteins from binding to DNA.
Suramin and several of its analogues are inhibitors of the DNA-binding protein Mcm10, which is essential for DNA replication. By binding to Mcm10, suramin likely interferes with its ability to interact with DNA or other replication factors. This mechanism links suramin binding to effects on DNA metabolism and cell cycle progression.
Disruption of Protein-Protein Interactions
In simple terms: Suramin can break up protein complexes.
Suramin inhibits antibody binding to cell surface antigens and disrupts complement-mediated mesangial cell lysis, demonstrating that suramin binding can interfere with protein-protein interactions at the cell surface. This broad ability to disrupt interactions is consistent with suramin's capacity to bind multiple proteins and modulate immune and inflammatory responses.
Key Genes Involved in GO:0043924 suramin binding
The following genes and proteins have been experimentally shown to bind suramin, as reported in the verified literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| PEBP1 | Raf1 kinase inhibitory protein; binds suramin at conserved pocket | Target for kinase regulation studies |
| Mcm10 | DNA replication protein; inhibited by suramin and analogues | DNA replication and cancer research |
| CALM1 | Calmodulin; suramin discriminates among binding sites | Calcium signaling and drug selectivity |
| IL4R | Interleukin-4 receptor; suramin blocks IL-4 binding | Immune signaling and tumor biology |
| gp120 (HIV-1) | HIV envelope glycoprotein; suramin inhibits V3 region binding to galactosylceramide | HIV entry and antiviral research |
| HCV envelope proteins | Hepatitis C virus proteins; suramin blocks binding to hepatoma cells | Antiviral strategies |
| DNA glycosylase (C. pseudotuberculosis) | DNA repair enzyme; suramin and heparin impede adenine binding | Bacterial DNA repair and antibiotic development |
| Cell surface antigens | Antibody targets; suramin inhibits antibody binding | Autoimmune and complement research |
| Galactosylceramide receptor | HIV-1 gp120 receptor on colon epithelial cells; suramin inhibits binding | HIV transmission and mucosal immunity |
| Heparin-binding proteins | Various proteins that bind polyanions; suramin competes | Polyanion-protein interaction studies |
| NF307 target (calmodulin) | Suramin analogue NF307 discriminates calmodulin sites | Drug design and selectivity |
| Adenine-binding proteins | Proteins that bind free adenine; suramin interferes | Nucleotide metabolism and DNA repair |
How Is suramin binding Regulated?
Suramin binding is not a genetically regulated process per se; rather, it is a chemical interaction that depends on the presence of suramin and the availability of binding sites on target proteins. However, the expression levels of suramin-binding proteins can influence the cellular response to suramin. For example, the abundance of Mcm10 or IL-4 receptors may modulate sensitivity to suramin [5,7]. Additionally, post-translational modifications or conformational changes in target proteins could affect suramin binding, though specific regulatory mechanisms are not well defined in the cited literature.
suramin binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| PEBP1 | Cancer signaling, kinase regulation | Knockout or point-mutation cell lines to study suramin binding |
| Mcm10 | DNA replication stress, cancer | Knockdown or knockout models to assess suramin sensitivity |
| IL4R | Tumor immunology, allergic inflammation | Overexpression or knockout to test suramin inhibition |
| gp120 (HIV-1) | HIV entry and transmission | Pseudovirus entry assays with suramin |
| HCV envelope proteins | Hepatitis C infection | Hepatoma cell binding assays |
Suramin binding in viral infections
Suramin binding to viral envelope proteins or host receptors can block viral entry. Suramin inhibits hepatitis C binding to human hepatoma cells, suggesting a potential role in antiviral therapy. Similarly, suramin inhibits binding of the V3 region of HIV-1 gp120 to galactosylceramide, a receptor on colon epithelial cells, highlighting its potential to prevent HIV transmission. These findings support further investigation of suramin and its analogues as entry inhibitors.
Suramin binding in cancer and cell signaling
Suramin binding to growth factor receptors and signaling proteins can interfere with tumor cell proliferation. For instance, suramin blocks interleukin-4 binding to its receptors on human tumor cells, inhibiting IL-4-induced mitogenic responses. Suramin also targets Raf1 kinase inhibitory protein, which is involved in kinase signaling pathways. These interactions suggest that suramin binding could be exploited to modulate cancer cell signaling.
Suramin binding in DNA replication and repair
Suramin inhibits the DNA-binding protein Mcm10, which is essential for DNA replication, and impedes adenine binding to a DNA glycosylase involved in DNA repair [2,5]. These effects link suramin binding to processes critical for genome maintenance, with implications for cancer and infectious diseases.
Suramin binding in immune and complement-mediated diseases
Suramin inhibits antibody binding to cell surface antigens and disrupts complement-mediated mesangial cell lysis, suggesting a potential role in modulating autoimmune or inflammatory conditions. This broad immunomodulatory effect warrants further study in disease models.
From suramin binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does suramin binding to PEBP1 affect kinase signaling? | PEBP1 knockout or point-mutation cell lines |
| Can suramin inhibit Mcm10 function in DNA replication? | Mcm10 knockout or knockdown cells |
| Does suramin block IL-4 receptor binding? | IL4R overexpression or knockout cells |
| Can suramin prevent HIV gp120 binding to galactosylceramide? | Colon epithelial cell lines with gp120 binding assays |
| Does suramin interfere with DNA glycosylase activity? | Bacterial or mammalian DNA glycosylase knockout models |
| Does suramin disrupt antibody binding to cell surface antigens? | Mesangial cell lines with complement lysis assays |
How to Study the suramin binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Surface plasmon resonance (SPR) | Binding affinity and kinetics | Characterizing suramin-protein interactions |
| Isothermal titration calorimetry (ITC) | Thermodynamics of binding | Quantifying suramin binding |
| Competition ELISA | Inhibition of ligand binding | Testing suramin as a competitor |
| Cell proliferation assay | Functional effect on cell growth | Assessing suramin's impact on mitogenic signaling |
| Viral entry assay | Inhibition of viral binding | Evaluating suramin as an antiviral [3,8] |
| DNA replication assay | Effect on DNA synthesis | Testing suramin inhibition of Mcm10 |
| X-ray crystallography | Atomic structure of complex | Visualizing suramin binding pocket |
| Fluorescence polarization | Binding-induced changes in polarization | High-throughput screening for suramin binding |
Binding assays
Direct binding of suramin to proteins can be measured using surface plasmon resonance (SPR), isothermal titration calorimetry (ITC), or fluorescence polarization. These methods provide quantitative affinity data and are essential for characterizing suramin binding [1,2,4].
Competition assays
To test whether suramin competes with natural ligands, competition assays such as ELISA or radioligand binding can be used. For example, suramin's ability to block IL-4 binding to its receptor was demonstrated using such assays. Similarly, suramin inhibition of HIV gp120 binding to galactosylceramide was shown by competition experiments.
Functional assays
Downstream functional effects of suramin binding can be assessed using cell proliferation, viral entry, or DNA replication assays. For instance, suramin's inhibition of IL-4-induced mitogenesis was measured by proliferation assays, and its effect on hepatitis C binding was tested using hepatoma cell binding assays.
Structural studies
X-ray crystallography or cryo-EM can reveal the atomic details of suramin binding to target proteins. The conserved ligand-binding pocket of Raf1 kinase inhibitory protein was identified through structural analysis. Such studies guide the design of more selective suramin analogues.
How CRISPR Can Be Used to Study GO:0043924 suramin binding
Knockout
CRISPR knockout of genes encoding suramin-binding proteins, such as PEBP1 or Mcm10, can help determine whether these proteins are required for suramin's cellular effects. For example, Mcm10 knockout cells may show altered sensitivity to suramin-induced replication stress. Knockout models are valuable for target validation.
Point Mutation
Introducing point mutations in the suramin-binding pocket of target proteins can abolish or enhance suramin binding. For instance, mutating key residues in the conserved pocket of Raf1 kinase inhibitory protein could test the specificity of suramin binding. Such models help dissect the molecular determinants of suramin recognition.
Knock-in
Knock-in of tagged versions of suramin-binding proteins, such as GFP- or HA-tagged Mcm10, allows visualization and pull-down of the protein to study suramin binding in live cells. Tagged knock-in models facilitate localization and interaction studies.
Overexpression
Overexpression of suramin-binding proteins like IL-4 receptor or calmodulin can amplify suramin's effects and enable biochemical studies. Overexpression models are useful for producing sufficient protein for binding assays and structural studies [4,7].
How EDITGENE Supports suramin binding Research
Researchers studying suramin binding-related genes often need to determine whether a candidate gene is causally involved in suramin's cellular effects or simply a bystander. EDITGENE provides CRISPR-based cell model services to enable precise genetic manipulation and functional validation.
Contact EDITGENE today to design your custom CRISPR model for suramin binding research.
Frequently Asked Questions About suramin binding
What is suramin binding?
Suramin binding is a molecular function (GO:0043924) where a protein or macromolecule interacts with suramin, a naphthalenesulfonic acid compound used to treat trypanosomiasis and onchocerciasis [1,2,3,4,5,6,7,8].
What genes are involved in suramin binding?
Genes encoding proteins that bind suramin include PEBP1, Mcm10, CALM1, IL4R, and viral proteins such as HIV-1 gp120 and HCV envelope proteins [1,3,4,5,7,8].
How does suramin bind to proteins?
Suramin typically binds through electrostatic interactions with positively charged pockets or polyanion-binding sites on proteins, often competing with natural ligands like heparin or nucleic acids [1,2,4].
What is the GO ID for suramin binding?
The Gene Ontology ID for suramin binding is GO:0043924.
Is suramin binding involved in disease?
Yes, suramin binding can block viral entry, inhibit tumor cell signaling, and interfere with DNA replication and repair, making it relevant to viral infections, cancer, and other diseases [3,5,7,8].
What proteins bind suramin?
Proteins reported to bind suramin include Raf1 kinase inhibitory protein, Mcm10, calmodulin, interleukin-4 receptor, HIV-1 gp120, and hepatitis C envelope proteins [1,3,4,5,7,8].
How can I study suramin binding?
Common methods include surface plasmon resonance, isothermal titration calorimetry, competition assays, and functional cell-based assays [1,2,4,7].
What are the synonyms for suramin binding?
The synonym for suramin binding is Germanin binding.
Can CRISPR be used to study suramin binding?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models can be used to dissect the role of specific genes in suramin binding and its cellular effects [1,5,7].
Why is suramin binding important for drug discovery?
Understanding suramin binding helps repurpose suramin for new indications and design more selective analogues with fewer side effects [1,3,5,7].
Conclusion
GO:0043924 suramin binding is a molecular function that captures the interaction of suramin with a diverse array of proteins, from kinases and DNA-binding proteins to cell surface receptors. This binding often occurs through electrostatic interactions and can disrupt protein-protein or protein-nucleic acid interactions, explaining suramin's broad biological and therapeutic effects [1,2,3,4,5,6,7,8]. Continued research using CRISPR models and advanced binding assays will further illuminate the mechanisms and potential applications of suramin binding in human disease.
References
- 1. Guo C et al.. 2021. Suramin Targets the Conserved Ligand-Binding Pocket of Human Raf1 Kinase Inhibitory Protein.. Molecules 26(4) PMID: 33670019
- 2. Eberle RJ et al.. 2019. The polyanions heparin and suramin impede binding of free adenine to a DNA glycosylase from C. pseudotuberculosis.. Int J Biol Macromol 125:459-468 PMID: 30529553
- 3. Garson JA et al.. 1999. Suramin blocks hepatitis C binding to human hepatoma cells in vitro.. J Med Virol 57(3):238-42 PMID: 10022794
- 4. Klinger M et al.. 2001. Suramin and the suramin analogue NF307 discriminate among calmodulin-binding sites.. Biochem J 355(Pt 3):827-33 PMID: 11311147
- 5. Paulson CN et al.. 2019. The anti-parasitic agent suramin and several of its analogues are inhibitors of the DNA binding protein Mcm10.. Open Biol 9(8):190117 PMID: 31409229
- 6. Piao H et al.. 2016. Suramin inhibits antibody binding to cell surface antigens and disrupts complement-mediated mesangial cell lysis.. J Pharmacol Sci 132(4):224-234 PMID: 27103329
- 7. Leland P et al.. 1995. Suramin blocks binding of interleukin-4 to its receptors on human tumor cells and interleukin-4-induced mitogenic response.. Oncol Res 7(5):227-35 PMID: 8534928
- 8. Yahi N et al.. 1994. Suramin inhibits binding of the V3 region of HIV-1 envelope glycoprotein gp120 to galactosylceramide, the receptor for HIV-1 gp120 on human colon epithelial cells.. J Biol Chem 269(39):24349-53 PMID: 7929093
