The crucial role of Myc as an oncoprotein and as a key regulator of cell growth makes it essential to understand the molecular basis of Myc function. The N-terminal region of c-Myc coordinates a wealth of protein interactions involved in transformation, differentiation and apoptosis. We have characterized in detail the ...

A series of 1,8-dipyrazolcarbazole (DPC) derivatives (6a-6d, 7a-7d) designed as G-quadruplex ligands have been synthesized and characterized. The FRET-melting and SPR results showed that the DPC derivatives could well recognize G-quadruplex with strong discrimination against the duplex DNA. In addition, the DPC derivatives showed much stronger stabilization activities and binding ...

Myosins are ATP-driven linear molecular motors that work as cellular force generators, transporters, and force sensors. These functions are driven by large-scale nucleotide-dependent conformational changes, termed "strokes"; the "power stroke" is the force-generating swinging of the myosin light chain-binding "neck" domain relative to the motor domain "head" while bound to ...

The eosinophil cationic protein (ECP) is an eosinophil-secreted RNase involved in the immune host defense, with a cytotoxic activity against a wide range of pathogens. During inflammation and eosinophilia disorders, ECP is secreted to the inflammation area, where it would contribute to the immune response. ECP secretion causes also severe ...

CryoTEM demonstrates that a CNA35-bearing liposomal MRI contrast agent selectively binds to poorly assembled collagen type I as opposed to well-assembled collagen fibrils, whereas monomeric CNA35 binds to all forms of collagen. It is shown that upon conjugation to liposomes and micelles CNA35 loses its ability to dissociate ordered collagen ...

Heparin derivative-based therapy has evolved from unfractionated heparin (UFH) to low-molecular-weight heparins (LMWHs) and now fondaparinux, a synthetic pentasaccharide. Contrary to UFH or LMWHs, fondaparinux is not neutralized by protamine sulfate, and no antidote is available to counteract bleeding disorders associated with overdosing. To make the use of fondaparinux safer, ...

Terminal 1,6-anhydro-aminosugars (1,6-anAS) are typical structural moieties of enoxaparin, a low-molecular-weight heparin (LMWH) widely used for prevention and treatment of thrombotic disorders. In the enoxaparin manufacturing process, these modified amino sugars are formed during the β-eliminative cleavage of heparin. To investigate the effect of terminal anAS on antithrombin (AT) binding ...

The presence of heparin binding has been become crucial in exerting growth factor related tissue formation. Receptor-mediated osteoblastic differentiation by bone morphogenetic protein (BMP)-4 and supportive function of its heparin binding has been proposed, direct role of the heparin binding site of BMP-4 on osteogenesis has not yet been fully ...

Polymer membrane-based electrodes sensitive to low molecular weight heparin (LMWH) have been used to examine the binding between several preparations of LMWH and heparin-binding foldamers, which have recently been developed as potential inhibitors of the anticoagulant activity of LMWHs. It was found that the structure of the heparin-binding foldamer affects ...

The serpin, antithrombin, requires allosteric activation by a sequence-specific pentasaccharide unit of heparin or heparan sulfate glycosaminoglycans to function as an anticoagulant regulator of blood clotting proteases. Surprisingly, X-ray structures have shown that the pentasaccharide produces similar induced-fit changes in the heparin binding site of native and latent antithrombin despite ...

Dermatan sulfate, an important member of the glycosaminoglycan family, interacts with heparin cofactor II, a member of the serpin family of proteins, to modulate antithrombotic response. Yet, the nature of this interaction remains poorly understood at a molecular level. We report the genetic algorithm-based combinatorial virtual library screening study of ...

The preparation and characterization of heparin-immobilized microspheres which were used to bind acidic fibroblast growth factor (aFGF), vascular endothelial growth factor (VEGF), monocyte chemoattractant protein 1 (MCP-1/CCL2), and regulation upon activation normal T cell express sequence (RANTES/CCL5) is described. These beads were used as trapping agents in microdialysis sampling experiments ...

Mycoplasma hyopneumoniae, the causative agent of porcine enzootic pneumonia, adheres to ciliated respiratory epithelia resulting in ciliostasis and epithelial cell death. The cilium adhesin P97 (Mhp183) contains two repeat regions, designated R1 and R2, that play key roles in adherence. Eight pentapeptide repeats in R1 are sufficient to bind porcine ...

Capsid proteins binding cell surface proteoglycans is a key early event in human papillomavirus (HPV) infection. The positively charged sequences at the C-terminus of the L1 protein and the N- and C-termini of the L2 protein of HPV-16 can efficiently bind to heparin receptors, which were characterized in the present ...

We report 3 cases of disease - leptospirosis, tropical malaria and fulminant meningococcaemia - associated with high serum concentrations of heparin-binding protein (HBP) and haemodynamic instability. Furthermore, HBP kinetics were observed for the first 3 days in survivors and were correlated with improvement in clinical condition.

Irreversible inactivation of alpha-thrombin (T) by the serpin, heparin cofactor II (HCII), is accelerated by ternary complex formation with the glycosaminoglycans (GAGs) heparin and dermatan sulfate (DS). Low expression of human HCII in Escherichia coli was optimized by silent mutation of 27 rare codons and five secondary Shine-Dalgarno sequences in ...

The critical and multiple roles of thrombin in blood coagulation are regulated by ligands and cofactors. Zymogen activation imparts proteolytic activity to thrombin and also affects the binding of ligands to its two principal exosites. We have used the activation peptide fragment 1.2 (F12), a ligand for anion-binding exosite 2, ...

Eosinophil cationic protein (ECP) is a highly stable, cytotoxic ribonuclease with the ability to enter and disrupt membranes that participates in innate immune defense against parasites but also kills human cells. We have used NMR spectroscopy to characterize the binding of ECP to membrane and heparin mimetics at a residue ...

In emergency cases anticoagulant action of heparin needs to be stopped instantaneously, which is usually achieved by intravenous administration of protamine sulfate (PS). However, PS shows many adverse effects. The objective of the present work was to find out if chitosan (Ch) and a cationically modified chitosan, N-(2-hydroxypropyl)-3-trimethylammonium chitosan chloride ...

The crystal structures of aprotinin and its complex with sucrose octasulfate (SOS), a polysulfated heparin analog, were determined at 1.7-2.6A resolutions. Aprotinin is monomeric in solution, which associates into a decamer at high salt concentrations. Sulfate ions serve to neutralize the basic amino acid residues of aprotinin to stabilize the ...

The host vasculature is believed to constitute the principal route of dissemination of Neisseria meningitidis (Nm) throughout the body, resulting in septicaemia and meningitis in susceptible humans. In vitro, the Nm outer membrane protein Opc can enhance cellular entry and exit, utilising serum factors to anchor to endothelial integrins; but ...

Clinically significant age-related differences in the anticoagulation effect of heparin have previously been established in vitro as well as in different clinical settings in vivo. These differences were hypothesized to be due to the age-specific differences in binding of heparin to plasma proteins. The aim of this project was to ...

Many studies have examined consensus sequences required for protein-glycosaminoglycan interactions. Through the synthesis of helical heparin binding peptides, this study probes the relationship between spatial arrangement of positive charge and heparin binding affinity. Peptides with a linear distribution of positive charge along one face of the alpha-helix had the highest ...

Heparin Binding Hemagglutinin A (HBHA) is hitherto the sole virulence factor associated with tuberculosis dissemination from the lungs, the site of primary infection, to epithelial cells. We have previously reported the solution structure of HBHA, a dimeric and elongated molecule. Since oligomerisation of HBHA is associated with its ability to ...

Inactivation of thrombin (T) by the serpins heparin cofactor II (HCII) and antithrombin (AT) is accelerated by a heparin template between the serpin and thrombin exosite II. Unlike AT, HCII also uses an allosteric interaction of its NH(2)-terminal segment with exosite I. Sucrose octasulfate (SOS) accelerated thrombin inactivation by HCII ...

Fluorescent perylenediimide probes modified with 2, 4, 6, or 8 ammonium groups were synthesized and their binding to the antithrombotic drug heparin was studied by fluorescence spectroscopy in solution. The polyanionic polysaccharide strands of heparin bind more probe molecules per sugar unit when the charge of the latter is low, ...

The flavivirus envelope protein is the dominant antigen in eliciting neutralizing antibodies and plays an important role in inducing immunologic responses in the infected host. It has been shown that highly sulfated forms of heparin sulfate can bind to the envelope protein and are involved in flavivirus infection. Among the ...

The importance of growth factors has been recognized for over five decades; however their utilization in medicine has yet to be fully realized. This is because free growth factors have short half-lives in plasma, making direct injection inefficient. Many growth factors are anchored and protected by sulfated glycosaminoglycans in the ...

Endostatin is a potent angiogenesis inhibitor with heparin-dependent activities. Nucleolin, a novel functional receptor of endostatin, mediates both the internalization to endothelial cells and the antiangiogenic activity of endostatin. To define the exact role of the heparin binding motif in mediating the interaction between endostatin and its receptor nucleolin, up ...

Polyphosphate (a linear polymer of inorganic phosphate) is secreted from platelet dense granules, and we recently showed that it accelerates factor V activation by thrombin. To examine the interaction of polyphosphate with thrombin. Thrombin, but not prothrombin, altered the electrophoretic migration of polyphosphate in gel mobility assays. Thrombin binding to ...

Neurofibrillary tangles, principally composed of bundles of filaments formed by the microtubule-associated protein Tau, are a hallmark of a group of neurodegenerative diseases such as Alzheimer disease. Polyanionic cofactors such as heparin can induce Tau filament formation in vitro. Here we quantitatively characterize the interaction between recombinant human Tau fragment ...

The longer splice isoforms of VEGF (vascular endothelial growth factor)-A, including VEGF(164(165)), contain a highly basic HBD (heparin-binding domain). This domain allows these isoforms to interact with and localize to the HS (heparan sulfate)-rich extracellular matrix, and bind to the co-receptor Nrp-1 (neuropilin-1). Heparin-binding VEGF-A isoforms are critical for survival: ...

The amyloid beta-peptide deposit found in the brain tissue of patients with Alzheimer disease is derived from a large heparin-binding protein precursor APP. The biological function of APP and its homologs is not precisely known. Here we report the x-ray structure of the E2 domain of APL-1, an APP homolog ...

A proteoglycan (PG) monomer is a macromolecule consisting of one or more glycosaminoglycan (GAG) chains attached to a core protein. PGs have signaling roles and modulatory functions in the extracellular matrix and at the cell surface. To elucidate the functions of higher-order PG structures, pseudoPGs that imitate the PG structure ...

The thermoreversible hydrogel of poly(N-isopropylacrylamide-co-acrylic acid) [p(NiPAAm-co-AAc)] was utilized in an injectable protein (growth factor) delivery system for use in tissue regeneration protocols. The transforming growth factor beta (TGF beta) proteins, which have been shown to bind to heparin, have been well established to induce chondrogenic differentiation in chondrocytes. In ...

Heparin possesses antimetastatic effects that were related to various molecular mechanisms beyond anticoagulant activities. The ability of heparin to interfere with the function of adhesion receptors in the metastatic course appears as a promising therapeutic approach. This refers to numerous findings that heparin attenuates metastasis in a selectin-dependent manner. We ...

Extracellular superoxide dismutase (ECSOD) interacts with heparin through its C-terminal domain. In this study we used isothermal titration calorimetry (ITC) to get detailed thermodynamic information about the interaction. We have shown that the interaction between ECSOD and intestinal mucosal heparin (M(w) 6000-30000 Da) is exothermic and driven by enthalpy at ...

The regulatory properties of thrombin are derived predominantly from its capacity to produce different functional conformations. Functional studies have revealed that two antagonistic thrombin conformations exist in equilibrium: the fast (procoagulant) and slow (anticoagulant) forms. The mechanisms whereby thrombin activity is regulated by the binding of different effectors remain among ...

A new quinine derivative PQ, bearing pyrenyl as a fluorophore, was prepared to recognize heparin in aqueous solution. PQ exhibits good selectivity and sensitivity for heparin over other biological molecules. Upon binding with heparin, PQ shows a typical excimer emission peaked at 489 nm along with a weak monomer emission ...

Osteopontin (OPN) is a proinflammatory cytokine that plays an important role in the pathogenesis of rheumatoid arthritis (RA). OPN can be cleaved by thrombin, resulting in OPN-R and exposing the cryptic C-terminal alpha4beta1 and alpha9beta1 integrin-binding motif (SVVYGLR). Thrombin-activatable carboxypeptidase B (CPB), also called thrombin-activatable fibrinolysis inhibitor, removes the C-terminal ...

Histidine-rich glycoprotein (HRG) is a heparin-binding glycoprotein present in plasma at 100microg/ml. A recent study revealed that HRG suppressed heparin-dependent basic fibroblast growth factor (bFGF)-induced angiogenesis. Additionally, we reported that high mobility group box 1 (HMGB1) in complex with heparin induces angiogenesis; therefore, we examined the effect of HRG on ...

Heparan sulfate (HS) proteoglycans (PGs) interact with a number of extracellular signaling proteins, thereby playing an essential role in the regulation of many physiological processes. One major function of HS is to interact with fibroblast growth factors (FGFs) and their receptors (FGFRs) and form FGF.HS.FGFR signaling complexes. Past studies primarily ...

A major limitation in biopharmaceutical development is selectively targeting drugs to diseased tissues. Growth factors and viruses have solved this problem by targeting tissue-specific cell-surface heparan sulfates. Neuregulin (NRG), a growth factor important in both nervous system development and cancer, has a unique heparin-binding domain (HBD) that targets to cell ...

The small leucine-rich repeat proteins, fibromodulin and osteoadherin, have N-terminal extensions with a variable number of O-sulfated tyrosine residues. This modification combined with a number of aspartic and glutamic acid residues results in a highly negatively charged domain of less than 30 amino acids. We hypothesized that this domain shares ...

Staphylokinase (SAK) is an effective thrombolysis agent for therapy of myocardial infarction. We have constructed a fusion SAK variant (SAK-HV) with a thrombin-binding domain composed of 12 amino acids from hirudin and expressed it in Escherichia coli and purified the resultant protein. SAK-HV maintained fibrinolytic activity similar to SAK and ...

Heparin and heparan sulfate glycosaminoglycans allosterically activate the serpin, antithrombin, by binding through a specific pentasaccharide sequence containing a critical 3-O-sulfo group. To elucidate the role of the 3-O-sulfo group in the activation mechanism, we compared the effects of deleting the 3-O-sulfo group or mutating the Lys(114) binding partner of ...

Interaction between the receptor for advanced glycation end products (RAGE) and its ligands has been implicated in the pathogenesis of various inflammatory disorders. In this study, we establish an in vitro binding assay in which recombinant human high-mobility group box 1 (rhHMGB1) or recombinant human S100A12 (rhS100A12) immobilized on the ...

AMBN (ameloblastin) is an enamel matrix protein that regulates cell adhesion, proliferation, and differentiation of ameloblasts. In AMBN-deficient mice, ameloblasts are detached from the enamel matrix, continue to proliferate, and form a multiple cell layer; often, odontogenic tumors develop in the maxilla with age. However, the mechanism of AMBN functions ...

Glial cell line-derived neurotrophic factor (GDNF) protects and repairs dopamine neurons. It binds to GDNF family receptor alpha1 (GFRalpha1) and activates receptor tyrosine kinase. Heparan sulphate proteoglycans (HSPGs) also participate in the signalling of GDNF, though binding to HS may hinder the diffusion of infused GDNF. We assessed the importance ...

Human FGF1 (fibroblast growth factor 1) is a powerful signaling molecule with a short half-life in vivo and a denaturation temperature close to physiological. Binding to heparin increases the stability of FGF1 and is believed to be important in the formation of FGF1.fibroblast growth factor receptor (FGFR) active complex. In ...