GO:0036143 kringle domain binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0036143 (kringle domain binding) is a molecular function defined as binding to a kringle domain, a protein fold stabilized by three disulfide linkages that mediates protein-protein interactions with blood coagulation factors.
• Kringle domains are found in plasminogen, tissue-type plasminogen activator (PLAT), hepatocyte growth factor (HGF), urokinase (PLAU), factor XII (F12), and lipoprotein(a).
• Kringle domain binding is central to fibrinolysis, coagulation, cell migration, and lipoprotein(a) assembly, making it a target for cardiovascular and metabolic disease research.
• The kringle-2 domain of tissue-type plasminogen activator binds fibrin, and this interaction is inhibited by epsilon-amino caproic acid, a classic lysine analog.
• Streptococcal PAM-type M-protein binds the kringle-2 domain of human plasminogen, causing dissociation of PAM dimers, a mechanism relevant to bacterial pathogenesis.
• Small-molecule inhibitors of lipoprotein(a) formation target kringle domain interactions, demonstrating therapeutic potential of modulating this function.
Description
Kringle domain binding (GO:0036143) is a molecular function that describes the binding of a protein or ligand to a kringle domain, a compact protein fold characterized by large loops stabilized by three disulfide linkages. Kringle domains are best known for their roles in blood coagulation and fibrinolysis, where they mediate protein-protein and protein-ligand interactions. This GO term is essential for annotating gene products that recognize kringle domains, including coagulation factors, proteases, and receptors. Understanding kringle domain binding is critical because it underlies key physiological processes such as clot dissolution, extracellular matrix remodeling, and cell signaling. For researchers, GO:0036143 provides a precise functional label for proteins that interact with kringle-containing molecules, facilitating comparative genomics, functional enrichment, and drug target discovery. The term is particularly relevant to cardiovascular biology, cancer, and infectious disease, where kringle-mediated interactions drive pathology.
kringle domain binding At A Glance
| GO ID | GO:0036143 |
|---|---|
| GO term | kringle domain binding |
| Ontology | molecular_function |
| Synonym | none |
| Major function | Binding to kringle domains to mediate protein-protein interactions, especially with blood coagulation factors |
| Definition source | QuickGO |
| Related processes | Fibrinolysis, coagulation, cell migration, lipoprotein assembly |
| Example proteins | Plasminogen, tissue-type plasminogen activator (PLAT), hepatocyte growth factor (HGF), urokinase (PLAU), factor XII (F12), lipoprotein(a) |
What Is GO:0036143?
Kringle domain binding is the molecular function of selectively interacting with a kringle domain, a protein structural motif that folds into large loops held together by three disulfide bonds. This binding event is important for protein-protein interactions involving blood coagulation factors and other plasma proteins.
Why Is kringle domain binding Important in Cell Biology?
Kringle domain binding is important because it governs molecular recognition events that are central to hemostasis, thrombosis, and vascular biology. Many kringle-containing proteins, such as plasminogen and tissue-type plasminogen activator, rely on kringle domain interactions to localize to fibrin clots and initiate fibrinolysis. Disruption of these interactions can lead to bleeding disorders or thrombotic disease. In addition, kringle domain binding is exploited by pathogens: streptococcal PAM-type M-protein binds plasminogen kringle-2 to promote bacterial dissemination. Therapeutically, inhibiting kringle domain interactions is a strategy for lowering lipoprotein(a), a risk factor for cardiovascular disease. Thus, GO:0036143 is a key annotation for understanding and manipulating these clinically relevant pathways.
• Regulates fibrinolysis by mediating plasminogen and tissue-type plasminogen activator binding to fibrin.
• Contributes to blood coagulation factor assembly and function, including factor XII.
• Facilitates bacterial pathogenesis through streptococcal PAM-type M-protein binding to plasminogen kringle-2.
• Involved in lipoprotein(a) formation, a major cardiovascular risk factor.
• Mediates heparin binding to urokinase and hepatocyte growth factor kringle domains.
• Supports cell migration and tissue remodeling via hepatocyte growth factor signaling.
• Provides a target for small-molecule inhibitors of lipoprotein(a).
• Enables bioinformatics annotation of kringle-mediated interactions in proteomes.
• Relevant to cancer biology through plasminogen activation and extracellular matrix degradation.
• Aids in understanding receptor interactions, such as plasminogen kringle 5 with Cochlin vWA1 domain.
What Happens During kringle domain binding?
Ligand recognition by kringle domains
In simple terms: A kringle domain grabs onto a specific partner molecule, like a lock and key.
Kringle domains recognize ligands through surface-exposed loops and conserved lysine-binding sites. For example, the kringle-2 domain of tissue-type plasminogen activator binds fibrin, and this interaction is inhibited by epsilon-amino caproic acid, indicating the involvement of lysine-binding pockets. Similarly, the kringle-2 domain of human plasminogen binds streptococcal PAM-type M-protein, causing dissociation of PAM dimers. These binding events are highly specific and depend on the three-disulfide-stabilized fold of the kringle domain.
Conformational changes and complex assembly
In simple terms: Binding can change the shape of the proteins and make them assemble into larger complexes.
Ligand binding to kringle domains can induce conformational changes. For instance, binding of the kringle-2 domain of human plasminogen to PAM-type M-protein causes dissociation of PAM dimers, suggesting a rearrangement of quaternary structure. Structural characterization of tissue-type plasminogen activator kringle 2 by 1H-NMR revealed ligand-induced changes in the domain. These conformational shifts are critical for downstream functions such as activation of plasminogen or assembly of lipoprotein(a).
Functional consequences in coagulation and fibrinolysis
In simple terms: Once bound, kringle domains help form or break blood clots.
Kringle domain binding is essential for the localization of fibrinolytic enzymes to clots. Tissue-type plasminogen activator binds fibrin via its kringle-2 domain, promoting plasminogen activation and clot lysis. Factor XII structure-function relationships involve kringle domain interactions that contribute to coagulation. In addition, heparin binding to the urokinase kringle domain modulates its activity, and the hairpin loop and second kringle domain of hepatocyte growth factor are required for heparin binding and biological activity.
Pathogen exploitation and therapeutic targeting
In simple terms: Some bacteria use kringle binding to spread, and drugs can block these interactions.
Streptococcal PAM-type M-protein binds human plasminogen kringle-2 to acquire proteolytic activity, aiding bacterial invasion. Small-molecule inhibitors of lipoprotein(a) formation target kringle domain interactions, offering a therapeutic approach for cardiovascular disease. The plasminogen kringle 5 domain interacts with the vWA1 domain of Cochlin, a mechanism studied for potential receptor functions. These examples highlight kringle domain binding as a druggable and pathogenic interface.
Key Genes Involved in GO:0036143 kringle domain binding
The following genes encode proteins that contain kringle domains or bind to them, and are central to research on GO:0036143.
| Gene | Major Role | Research Relevance |
|---|---|---|
| PLG | Plasminogen; contains five kringle domains; binds fibrin and pathogens | Fibrinolysis, bacterial pathogenesis |
| PLAT | Tissue-type plasminogen activator; kringle-2 binds fibrin | Thrombolysis, stroke therapy |
| HGF | Hepatocyte growth factor; kringle domains mediate heparin binding | Cell migration, cancer |
| PLAU | Urokinase; kringle domain binds heparin | Cancer invasion, metastasis |
| F12 | Factor XII; kringle domain in coagulation | Thrombosis, inflammation |
| LPA | Lipoprotein(a); kringle-containing apolipoprotein(a) | Cardiovascular risk |
| COCH | Cochlin; vWA1 domain binds plasminogen kringle 5 | Hearing loss, receptor studies |
| SPN | Streptococcal PAM-type M-protein; binds plasminogen kringle-2 | Bacterial pathogenesis |
| SERPINE1 | Plasminogen activator inhibitor-1; regulates fibrinolysis | Thrombosis |
| FGA | Fibrinogen alpha chain; substrate for plasmin | Clot formation |
| FGB | Fibrinogen beta chain; substrate for plasmin | Clot formation |
| FGG | Fibrinogen gamma chain; substrate for plasmin | Clot formation |
| APOH | Beta-2-glycoprotein I; binds kringle domains | Antiphospholipid syndrome |
| KNG1 | Kininogen; interacts with coagulation factors | Coagulation |
| SERPINC1 | Antithrombin; regulates coagulation proteases | Thrombosis |
| PROC | Protein C; anticoagulant | Coagulation |
| PROS1 | Protein S; cofactor for protein C | Coagulation |
How Is kringle domain binding Regulated?
Kringle domain binding is regulated by the availability of ligands, post-translational modifications, and cofactors. For example, heparin binding to the urokinase kringle domain modulates its interaction with other molecules. The hairpin loop and second kringle domain of hepatocyte growth factor are essential for heparin binding and biological activity, indicating that glycosaminoglycans regulate kringle-mediated functions. In the fibrinolytic system, epsilon-amino caproic acid inhibits kringle-2 binding to fibrin, showing that lysine analogs can regulate these interactions. Additionally, factor XII structure-function relationships reveal that kringle domain interactions are influenced by activation state and cofactor binding. These regulatory mechanisms ensure that kringle domain binding occurs at the right time and place.
kringle domain binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| LPA | Cardiovascular disease | Knockout or point-mutation in hepatocytes to block kringle binding |
| PLG | Thrombosis, bacterial infection | Knockout mice or cell lines for plasminogen kringle-2 |
| F12 | Thrombosis, inflammation | Point-mutation knock-in of kringle domain in factor XII |
| COCH | Hearing loss | Knock-in of vWA1 domain mutations to study kringle 5 binding |
| HGF | Cancer, tissue repair | Overexpression of kringle domain mutants in cancer cell lines |
Cardiovascular disease and lipoprotein(a)
Elevated lipoprotein(a) is a risk factor for cardiovascular disease, and its assembly depends on kringle domain interactions. Small-molecule inhibitors that block kringle domain binding reduce lipoprotein(a) formation, offering a therapeutic strategy. Factor XII kringle domain interactions also contribute to thrombosis, making them targets for anticoagulant development.
Bacterial pathogenesis and infectious disease
Streptococcal PAM-type M-protein binds human plasminogen kringle-2, causing dissociation of PAM dimers and enhancing bacterial dissemination. This interaction is a virulence mechanism that could be targeted to prevent invasive infections.
Cancer and metastasis
Kringle domain binding is involved in cancer progression through plasminogen activation and hepatocyte growth factor signaling. Urokinase kringle domain heparin binding and HGF kringle-mediated activity promote cell migration and matrix degradation, processes linked to metastasis.
Hearing loss and receptor interactions
The plasminogen kringle 5 domain binds the vWA1 domain of Cochlin, a protein implicated in hearing loss. This interaction has been studied using biospecific technologies and molecular dynamics simulations, suggesting a role in cochlear function.
From kringle domain binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of kringle domain binding affect fibrinolysis? | PLG or PLAT knockout cell lines |
| Can point mutations in kringle-2 abolish fibrin binding? | Point-mutation knock-in of PLAT kringle-2 |
| Does kringle domain binding mediate lipoprotein(a) assembly? | Knock-in of LPA kringle mutations in hepatocytes |
| How does PAM-type M-protein binding alter plasminogen conformation? | Tagged knock-in of PLG kringle-2 for FRET |
| What is the role of HGF kringle domains in heparin binding? | Overexpression of HGF kringle deletion mutants |
| Does factor XII kringle domain contribute to coagulation? | Knockout of F12 kringle domain in plasma models |
How to Study the kringle domain binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Surface plasmon resonance (SPR) | Binding affinity and kinetics | Kringle 5 - vWA1 interaction |
| NMR spectroscopy | Structural changes upon ligand binding | tPA kringle 2 - ligand |
| Molecular dynamics simulation | Conformational dynamics of complexes | Kringle 5 - Cochlin vWA1 |
| Isothermal titration calorimetry (ITC) | Thermodynamics of binding | Kringle domain - heparin |
| Site-directed mutagenesis | Functional importance of residues | Kringle-2 fibrin binding |
| CRISPR knockout | Loss-of-function phenotypes | PLG, PLAT, LPA |
| CRISPR knock-in | Point mutations or tags | Kringle domain point mutants |
| ELISA | Protein-protein interaction in vitro | PAM-plasminogen binding |
Surface plasmon resonance (SPR) and biospecific technologies
SPR measures real-time binding kinetics between kringle domains and their ligands. This method was used to investigate the binding mechanism of human plasminogen kringle 5 with the vWA1 domain of Cochlin. It provides quantitative affinity data (KD) and is ideal for screening inhibitors of kringle domain binding.
Nuclear magnetic resonance (NMR) spectroscopy
NMR can resolve structural changes in kringle domains upon ligand binding. 1H-NMR was used to characterize ligand binding to the tissue-type plasminogen activator kringle 2 domain, revealing specific residues involved in interaction. This method is valuable for mapping binding interfaces at atomic resolution.
Molecular dynamics simulations
Computational simulations complement experimental methods by modeling kringle domain interactions over time. Molecular dynamic simulation was applied to study the binding of plasminogen kringle 5 to the vWA1 domain of Cochlin, providing insights into stability and conformational changes.
Site-directed mutagenesis and CRISPR editing
Mutating key residues in kringle domains or their binding partners can test functional relevance. For example, epsilon-amino caproic acid inhibition of kringle-2 binding to fibrin was demonstrated using biochemical assays. CRISPR knockout or knock-in models can systematically dissect these interactions in cells.
How CRISPR Can Be Used to Study GO:0036143 kringle domain binding
Knockout
CRISPR knockout of genes encoding kringle domain-containing proteins (e.g., PLG, PLAT, LPA) can abolish kringle domain binding and reveal its role in fibrinolysis, coagulation, or lipoprotein(a) assembly. Knockout cell lines are essential for loss-of-function studies.
Point Mutation
Point mutations in kringle domains can disrupt specific binding interfaces. For example, mutating lysine-binding residues in the kringle-2 domain of tissue-type plasminogen activator can prevent fibrin binding, as suggested by epsilon-amino caproic acid inhibition studies. CRISPR point mutation models allow precise testing of these residues.
Knock-in
Knock-in of tagged or mutant kringle domains enables tracking and functional analysis. Tagged knock-in of plasminogen kringle-2 can be used to study PAM-type M-protein binding and dimer dissociation. Knock-in of disease-associated mutations in LPA or F12 can model cardiovascular risk.
Overexpression
Overexpression of kringle domain-containing proteins or their binding partners can amplify signaling or binding events. Overexpression of hepatocyte growth factor kringle mutants in cancer cell lines can test their role in heparin binding and cell migration. This approach is useful for gain-of-function studies.
How EDITGENE Supports kringle domain binding Research
Researchers studying kringle domain binding-related genes often need to determine whether a candidate gene is causally involved in fibrinolysis, coagulation, or lipoprotein metabolism. EDITGENE provides comprehensive CRISPR services to generate precisely engineered cell models for such investigations.
Contact EDITGENE today to design your custom CRISPR model for kringle domain binding research.
Frequently Asked Questions About kringle domain binding
What is kringle domain binding?
Kringle domain binding (GO:0036143) is the molecular function of binding to a kringle domain, a protein fold stabilized by three disulfide bonds that mediates interactions with blood coagulation factors.
What genes are involved in kringle domain binding?
Genes include PLG, PLAT, HGF, PLAU, F12, LPA, and COCH, which encode proteins containing kringle domains or binding to them.
What is the function of kringle domains?
Kringle domains mediate protein-protein interactions, particularly in blood coagulation and fibrinolysis, and can bind ligands such as fibrin and heparin.
How is kringle domain binding studied?
It is studied using surface plasmon resonance, NMR, molecular dynamics simulations, and CRISPR-based mutagenesis.
What diseases are associated with kringle domain binding?
Cardiovascular disease, thrombosis, bacterial infections, cancer, and hearing loss have been linked to kringle domain interactions.
Can kringle domain binding be targeted therapeutically?
Yes, small-molecule inhibitors of lipoprotein(a) formation target kringle domain interactions, and anticoagulants may target factor XII kringle domains.
What is the role of kringle-2 domain in tissue-type plasminogen activator?
The kringle-2 domain binds fibrin, and this interaction is inhibited by epsilon-amino caproic acid, facilitating clot lysis.
How does streptococcal PAM-type M-protein interact with plasminogen?
It binds the kringle-2 domain of human plasminogen, causing dissociation of PAM dimers and enhancing bacterial dissemination.
What is the significance of plasminogen kringle 5 binding to Cochlin?
This interaction with the vWA1 domain of Cochlin has been studied for its potential role in hearing loss and receptor function.
What CRISPR models are available for kringle domain binding research?
EDITGENE offers knockout, point mutation, knock-in, overexpression, and library screening models for genes involved in kringle domain binding.
Conclusion
Kringle domain binding (GO:0036143) is a molecular function critical for blood coagulation, fibrinolysis, and various pathological processes. Its role in mediating protein-protein interactions makes it a valuable target for therapeutic development and a key annotation in functional genomics. Researchers can leverage CRISPR models to dissect the precise contributions of kringle domains to health and disease.
References
- 1. Ayinuola O et al.. 2021. Binding of the kringle-2 domain of human plasminogen to streptococcal PAM-type M-protein causes dissociation of PAM dimers.. Microbiologyopen 10(6):e1252 PMID: 34964287
- 2. Diaz N et al.. 2024. Discovery of potent small-molecule inhibitors of lipoprotein(a) formation.. Nature 629(8013):945-950 PMID: 38720069
- 3. Zhang J et al.. 2022. Investigation of binding mechanism for human plasminogen Kringle 5 with its potential receptor vWA1 domain in Cochlin by bio-specific technologies and molecular dynamic simulation.. Bioorg Chem 127:105989 PMID: 35777236
- 4. Stephens RW et al.. 1992. Heparin binding to the urokinase kringle domain.. Biochemistry 31(33):7572-9 PMID: 1510944
- 5. Mizuno K et al.. 1994. Hairpin loop and second kringle domain are essential sites for heparin binding and biological activity of hepatocyte growth factor.. J Biol Chem 269(2):1131-6 PMID: 8288571
- 6. Shamanaev A et al.. 2024. Factor XII Structure-Function Relationships.. Semin Thromb Hemost 50(7):937-952 PMID: 37276883
- 7. Byeon IJ et al.. 1995. Ligand binding to the tissue-type plasminogen activator kringle 2 domain: structural characterization by 1H-NMR.. Biochemistry 34(9):2739-50 PMID: 7893685
- 8. van Zonneveld AJ et al.. 1986. On the interaction of the finger and the kringle-2 domain of tissue-type plasminogen activator with fibrin. Inhibition of kringle-2 binding to fibrin by epsilon-amino caproic acid.. J Biol Chem 261(30):14214-8 PMID: 3021732
