Heparinases can produce biologically active oligosaccharides by specifically cleaving the α-(1,4) glycosidic linkages of heparin and heparan sulphate. Heparinases are divided into heparinase and heparanase. Because heparinase is an effective biocatalyst, more and more researchers pay attention to the application of heparinase in medical field in the recent years. Combined with the related research work in our group, the application value of heparinase in the medical field was summarized, such as the determination of the structure of heparin, the preparation of low-molecular-weight heparin and ultra-low-molecular-weight heparin, tumor therapy and as a heparin antagonist. In addition, we summarized the definition, source of heparinase and its application in the medicine field. Heparinases have a great application prospect in the field of medicine.
Heparin ; Heparin Lyase ; metabolism ; Heparitin Sulfate ; Oligosaccharides ; Polysaccharide-Lyases

It is well known that the glomerular basement membrane heparan sulfate proteoglycan(GBM HSPG) synthesized by glomerular epithelial cell(GEC) has an important role in the permeability of glomerular basement membrane and cyclic AMP(cAMP) is involved in regulation of a wide variety of genes maybe including GBM HSPG gene. The direct effect of cAMP on GBM HSPG gene expression and metabolism was not evaluated as yet. Proteinuria represents an impairment of permselectivity function of glomerular basement membrane regulated by GBM HSPG and could be associated with increased glomerular level of cAMP in nephrotic syndrome of diverse causes. RPD-I(rat GBM HSPG core protein domain-I) detected a >9.5kb transcript of GBM HSPG in RNA of rat GEC. Emp1oying a riboprobe synthesized from RPD-I in RNase protection assay, we examined whether cAMP regulated perlecan expression in the GEC. At l, 6, 24 and 48 hrs of incubation, l mM cAMP caused 43%, 32%, 47% and 40% reduction in mRNA expression of perlecan, respectively. Immunoprecipitation showed a corresponding reduction of 51%, 70% and 68% in the synthesis of 35SO4 labeled GBM HSPG by the GEC fol1owing l2, 24 and 48 hrs of incubation with cAMP. Our results show that decrease in GBM HSPG gene expression and synthesis by cAMP may be of relevance to proteinuric states characterized by activation of these mediators.
Animals ; Cyclic AMP* ; Epithelial Cells* ; Gene Expression ; Glomerular Basement Membrane* ; Heparan Sulfate Proteoglycans* ; Heparitin Sulfate* ; Immunoprecipitation ; Metabolism ; Nephrotic Syndrome ; Permeability ; Proteinuria ; Rats* ; Ribonucleases ; RNA ; RNA, Messenger

Heparin and heparan sulfate are a class of glycosaminoglycans for clinical anticoagulation. Heparosan N-sulfate-glucuronate 5-epimerase (C5, EC 5.1.3.17) is a critical modifying enzyme in the synthesis of heparin and heparan sulfate, and catalyzes the inversion of carboxyl group at position 5 on D-glucuronic acid (D-GlcA) of N-sulfoheparosan to form L-iduronic acid (L-IdoA). In this study, the heparin C5 epimerase gene Glce from zebrafish was expressed and molecularly modified in Escherichia coli. After comparing three expression vectors of pET-20b (+), pET-28a (+) and pCold Ⅲ, C5 activity reached the highest ((1 873.61±5.42) U/L) with the vector pCold Ⅲ. Then we fused the solution-promoting label SET2 at the N-terminal for increasing the soluble expression of C5. As a result, the soluble protein expression was increased by 50% compared with the control, and the enzyme activity reached (2 409±6.43) U/L. Based on this, site-directed mutations near the substrate binding pocket were performed through rational design, the optimal mutant (V153R) enzyme activity and specific enzyme activity were (5 804±5.63) U/L and (145.1±2.33) U/mg, respectively 2.41-fold and 2.28-fold of the original enzyme. Modification and expression optimization of heparin C5 epimerase has laid the foundation for heparin enzymatic catalytic biosynthesis.
Animals ; Carbohydrate Epimerases ; biosynthesis ; chemistry ; genetics ; Escherichia coli ; Gene Expression ; Heparin ; metabolism ; Heparitin Sulfate ; metabolism ; Iduronic Acid ; metabolism ; Zebrafish Proteins ; biosynthesis ; chemistry ; genetics

Heparinase III (HepIII) is a 73-kDa polysaccharide lyase (PL) that degrades the heparan sulfate (HS) polysaccharides at sulfate-rare regions, which are important co-factors for a vast array of functional distinct proteins including the well-characterized antithrombin and the FGF/FGFR signal transduction system. It functions in cleaving metazoan heparan sulfate (HS) and providing carbon, nitrogen and sulfate sources for host microorganisms. It has long been used to deduce the structure of HS and heparin motifs; however, the structure of its own is unknown. Here we report the crystal structure of the HepIII from Bacteroides thetaiotaomicron at a resolution of 1.6 Å. The overall architecture of HepIII belongs to the (α/α)₅ toroid subclass with an N-terminal toroid-like domain and a C-terminal β-sandwich domain. Analysis of this high-resolution structure allows us to identify a potential HS substrate binding site in a tunnel between the two domains. A tetrasaccharide substrate bound model suggests an elimination mechanism in the HS degradation. Asn260 and His464 neutralize the carboxylic group, whereas Tyr314 serves both as a general base in C-5 proton abstraction, and a general acid in a proton donation to reconstitute the terminal hydroxyl group, respectively. The structure of HepIII and the proposed reaction model provide a molecular basis for its potential practical utilization and the mechanism of its eliminative degradation for HS polysaccarides.
Amino Acid Sequence ; Bacteroides ; enzymology ; Catalytic Domain ; Crystallography, X-Ray ; Heparitin Sulfate ; metabolism ; Kinetics ; Models, Molecular ; Molecular Sequence Data ; Polysaccharide-Lyases ; chemistry ; metabolism ; Substrate Specificity

COVID-19 represents the most serious public health event in the past few decades of the 21^st century. The development of vaccines, neutralizing antibodies, and small molecule chemical agents have effectively prevented the rapid spread of COVID-19. However, the continued emergence of SARS-CoV-2 variants have weakened the efficiency of these vaccines and antibodies, which brought new challenges for searching novel anti-SARS-CoV-2 drugs and methods. In the process of SARS-CoV-2 infection, the virus firstly attaches to heparan sulphate on the cell surface of respiratory tract, then specifically binds to hACE2. The S protein of SARS-CoV-2 is a highly glycosylated protein, and glycosylation is also important for the binding of hACE2 to S protein. Furthermore, the S protein is recognized by a series of lectin receptors in host cells. These finding implies that glycosylation plays important roles in the invasion and infection of SARS-CoV-2. Based on the glycosylation pattern and glycan recognition mechanisms of SARS-CoV-2, it is possible to develop glycan inhibitors against COVID-19. Recent studies have shown that sulfated polysaccharides originated from marine sources, heparin and some other glycans display anti-SARS-CoV-2 activity. This review summarized the function of glycosylation of SARS-CoV-2, discoveries of glycan inhibitors and the underpinning molecular mechanisms, which will provide guidelines to develop glycan-based new drugs against SARS-CoV-2.
Antibodies, Neutralizing ; Glycosylation ; Heparin ; Heparitin Sulfate ; Humans ; Polysaccharides/chemistry* ; Receptors, Mitogen/metabolism* ; SARS-CoV-2 ; Spike Glycoprotein, Coronavirus/metabolism* ; COVID-19 Drug Treatment

Mucopolysaccharidosis (MPS) III has 4 enzymatically distinct forms (A, B, C, and D), and MPS IIIC, also known as Sanfilippo C syndrome, is an autosomal recessive lysosomal storage disease caused by a deficiency of heparan acetyl-CoA:alpha-glucosaminide N-acetyltransferase (HGSNAT). Here, we report a case of MPS IIIC that was confirmed by molecular genetic analysis. The patient was a 2-yr-old girl presenting with skeletal deformity, hepatomegaly, and delayed motor development. Urinary excretion of glycosaminoglycan (GAG) was markedly elevated (984.4 mg GAG/g creatinine) compared with the age-specific reference range (<175 mg GAG/g creatinine), and a strong band of heparan sulfate was recognized on performing thin layer chromatography. HGSNAT enzyme activity in leukocytes was 0.7 nmol/17 hr/mg protein, which was significantly lower than the reference range (8.6-32 nmol/17 hr/mg protein). PCR and direct sequencing of the HGSNAT gene showed 2 mutations: c.234+1G>A (IVS2+1G>A) and c.1150C>T (p.Arg384*). To the best of our knowledge, this is the first case of MPS IIIC to be confirmed by clinical, biochemical, and molecular genetic findings in Korea.
Acetyltransferases/*genetics ; Asian Continental Ancestry Group/*genetics ; Base Sequence ; Child, Preschool ; Chromatography, Thin Layer ; Female ; Glycosaminoglycans/urine ; Heparitin Sulfate/chemistry/metabolism ; Humans ; Leukocytes/immunology/metabolism ; Mucopolysaccharidosis III/*diagnosis/genetics/radiography ; Mutation ; Republic of Korea ; Sequence Analysis, DNA

To explore the effects of platelet factor 4(PF4) on hematopoietic reconstitution and its mechanism in syngenic bone marrow transplantation (BMT). The syngenic BMT mice models were established. 20 and 26 h before irradiation, the mice were injected 20 micrograms/kg PF4 or PBS twice into abdominal cavity, then the donor bone marrow nuclear cells (BMNC) were transplanted. On the 7th day, spleen clone forming units (CFU-S) were counted. On the 7th, 14th and 21st day after BMT, the BMNC and megakaryoryocytes in bone marrow tissue were counted and the percentage of hematopoietic tissue and expression level of heparan sulfate in bone marrow tissue were assessed. In PF4-treated groups, the CFU-S counts on the 7th day were higher than those in BMT groups after BMT. The BMNC and megakaryoryocyte counts and the percentage of hematopoietic tissue and heparan sulfate expression level were higher than those in BMT group on the 7th, 14th and 21st day after BMT (P < 0.01 or P < 0.05). PF4 could accelerate hematopoietic reconstitution of syngenic bone marrow transplantation. The promotion of the heparan sulfate expression in bone marrow may be one of mechanisms of PF4.
Animals ; Bone Marrow Cells ; metabolism ; Bone Marrow Transplantation ; Female ; Hematopoietic Stem Cells ; cytology ; Heparitin Sulfate ; metabolism ; Male ; Mice ; Mice, Inbred BALB C ; Platelet Factor 4 ; pharmacology ; Radiation-Protective Agents ; pharmacology ; Random Allocation ; Spleen ; cytology ; Stem Cells ; Whole-Body Irradiation

Glycosaminoglycans are important structural components in the skin and exist as various proteoglycan forms, except hyaluronic acid. Heparan sulfate (HS), one of the glycosaminoglycans, is composed of repeated disaccharide units, which are glucuronic acids linked to an N-acetyl-glucosamine or its sulfated forms. To investigate acute ultraviolet (UV)-induced changes of HS and HS proteoglycans (HSPGs), changes in levels of HS and several HSPGs in male human buttock skin were examined by immunohistochemistry and real-time quantitative polymerase chain reaction (qPCR) after 2 minimal erythema doses (MED) of UV irradiation (each n = 4-7). HS staining revealed that 2 MED of UV irradiation increased its expression, and staining for perlecan, syndecan-1, syndecan-4, CD44v3, and CD44 showed that UV irradiation increased their protein levels. However, analysis by real-time qPCR showed that UV irradiation did not change mRNA levels of CD44 and agrin, and decreased perlecan and syndecan-4 mRNA levels, while increased syndecan-1 mRNA level. As HS-synthesizing or -degrading enzymes, exostosin-1 and heparanase mRNA levels were increased, but exostosin-2 was decreased by UV irradiation. UV-induced matrix metalloproteinase-1 expression was confirmed for proper experimental conditions. Acute UV irradiation increases HS and HSPG levels in human skin, but their increase may not be mediated through their transcriptional regulation.
Adult ; Agrin/genetics ; Antigens, CD44/genetics ; Base Sequence ; DNA Primers/genetics ; Gene Expression/radiation effects ; Glucuronidase/genetics ; Heparan Sulfate Proteoglycans/genetics/*metabolism ; Heparitin Sulfate/metabolism ; Humans ; Male ; Matrix Metalloproteinase 1/genetics ; N-Acetylglucosaminyltransferases/genetics ; RNA, Messenger/genetics/metabolism ; Skin/*metabolism/*radiation effects ; Skin Aging/genetics/physiology ; Syndecan-1/genetics ; Syndecan-4/genetics ; Ultraviolet Rays/*adverse effects ; Young Adult