To express and identify fibronectin C-terminal heparin-binding domain (FNCH BD) polypeptides in Pichia pastoris expression system and study its function, the fragment of FNCHBD was amplified by PCR and inserted into pGEM-T vector. After sequenced, the fragment was inserted into pAo815SM vector, and then cloned into the expression vector pPIC9k. The recombinant plasmid was linerarized with restrict enzyme Sal I and transferred into the yeast host cell KM71 and GS115. The positive yeast clone was screened by G418 resistant, and the target protein was induced to express in the medium containing 0.5% methanol. The culture supernatant was collected and then was purified with membrane ultrafiltration and ion exchange chromatography. The purified product was analyzed with mass spectrogram, SDS-PAGE, Western blotting and heparin affinity chromatography. The results showed that the target protein was around 32 kDa and the purity of the product was above 95%. FNCHBD could be specifically recognized by fibronectin polyclonal antibody. These results suggest that FNCHBD could be expressed and purified successfully in Pichia pastoris, which provides a good strategy to further studies.
Fibronectins ; biosynthesis ; chemistry ; genetics ; Genetic Vectors ; Heparin ; metabolism ; Peptides ; genetics ; metabolism ; Pichia ; genetics ; metabolism ; Protein Binding ; Protein Structure, Tertiary ; Recombinant Proteins ; biosynthesis ; chemistry ; genetics

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

Crystallography, X-Ray ; Escherichia coli ; metabolism ; Fibroblast Growth Factors ; chemistry ; genetics ; metabolism ; Heparin ; metabolism ; Humans ; Models, Molecular ; Protein Binding ; Protein Isoforms ; chemistry ; metabolism ; Protein Structure, Tertiary ; Recombinant Proteins ; biosynthesis ; chemistry ; genetics ; Sulfates ; chemistry ; metabolism

Bone morphogenetic protein-2 (BMP-2) is used to promote bone regeneration. However, the bone regeneration ability of BMP-2 relies heavily on the delivery vehicle. Previously, we have developed heparin-conjugated fibrin (HCF), a vehicle for long-term delivery of BMP-2 and demonstrated that long-term delivery of BMP-2 enhanced its osteogenic efficacy as compared to short-term delivery at an equivalent dose. The aim of this study was to compare the bone-forming ability of the BMP-2 delivered by HCF to that delivered by clinically utilized BMP-2 delivery vehicle collagen sponge. An in vitro release profile of BMP-2 showed that HCF released 80% of the loaded BMP-2 within 20 days, whereas collagen sponge released the same amount within the first 6 days. Moreover, the BMP-2 released from the HCF showed significantly higher alkaline phosphatase activity than the BMP-2 released from collagen sponge at 2 weeks in vitro. Various doses of BMP-2 were delivered with HCF or collagen sponge to mouse calvarial defects. Eight weeks after the treatment, bone regeneration was evaluated by computed tomography, histology, and histomorphometric analysis. The dose of BMP-2 delivered by HCF to achieve 100% bone formation in the defects was less than half of the BMP-2 dose delivered by collagen sponge to achieve a similar level of bone formation. Additionally, bone regenerated by the HCF-BMP-2 had higher bone density than bone regenerated by the collagen sponge-BMP-2. These data demonstrate that HCF as a BMP-2 delivery vehicle exerts better osteogenic ability of BMP-2 than collagen sponge, a clinically utilized delivery vehicle.
Alkaline Phosphatase/metabolism ; Animals ; Bone Density ; *Bone Morphogenetic Protein 2/administration & dosage/genetics ; Bone Regeneration/*genetics ; Cells, Cultured ; Collagen Type I/chemistry/metabolism ; *Fibrin/chemistry/metabolism ; *Gene Transfer Techniques ; *Heparin/chemistry/metabolism ; Mice ; Osteogenesis/genetics ; Rats ; Rats, Sprague-Dawley

The ionized calcium level in blood is known to be falsely decreased when self-prepared liquid heparin anticoagulant is used, due to dilution and binding effects. The effect of liquid heparin on the determination of ionized magnesium is not as well understood. We compared the effect of liquid sodium heparin on the determination of ionized calcium and magnesium in 44 clinical samples using two types of user-prepared heparin syringes which differed in the amount of residual heparin from the BD Preset(TM) reference syringe. With the type 1 syringe, the liquid heparin was expelled once or twice such that some heparin could be left in the dead space at the syringe hub, while the liquid sodium heparin was thoroughly expelled from the type 2 syringe. The ionized magnesium levels obtained with the type 1 syringe were significantly lower than the reference value (by 0.068 mmol/L) (p < 0.0001), while the value obtained with the type 2 syringe differed less from the reference, by only 0.014 mmol/L (p < 0.0001). The heparin binding effect resulted in more negative bias in ionized magnesium (-0.026 +/- 0.032 mmol/L) than in ionized calcium (-0.009 +/- 0.042 mmol/L, p < 0.0001). In conclusion, we recommend using lyophilized, calcium-balanced, heparinized syringes for the determination of ionized magnesium and ionized calcium due to the increased negative bias in ionized magnesium determinations. When user-prepared syringes are used, the thorough evacuation of heparin solution should be strictly prescribed.
Syringes ; Protein Binding ; Magnesium/*chemistry/metabolism ; Ions ; Humans ; Heparin/administration & dosage/*therapeutic use ; Calcium/*metabolism ; Blood Specimen Collection/*methods ; Blood Chemical Analysis/*methods ; Anticoagulants/therapeutic use

Phospholipase C(PLC) plays a central role in signal transduction and it is important in cellular growth, differentiation and transformation. There are currently ten known mammalian isozymes of PLC identified and cloned. However, there are no report of PLC distribution in human lung tissue or their significances in pulmonary diseases. Presence of various PLC isozymes in normal human lung tissue was studied from surgical specimens. PLC isozymes in tissue extracts of the lung were partially purified by successive chromatographic steps on heparin-sepharose CL-6B conventional and TSKgel heparin-5PW HPLC columns and their activities were assayed. PLC activity peaks identified in the chromatography were immunoblotted with specific antibodies against ten known mammalian PLC isozymes(PLC-beta 1-4, -gamma 1-2, and -delta 1-4). In addition, immunohistochemical staining of the lung tissue was performed to determine subcellular and histological localization of PLC isozymes. The results indicate that normal human lungs contain beta 1, beta 3, gamma 1, and delta 1, isozymes of PLC. The order of amount present in the lung tissue was PLC-delta 1 > gamma 1 >beta 1 >> beta 3, in descending order. On immunohistochemistry, PLC-gamma 1 was most widely distributed and was present in bronchiolar epithelium, in type I and type II pneumocytes as well as in fibroblasts of the interstitial tissue. PLC-delta 1 was present in the cytoplasm of the bronchiolar epithelium whereas PLC-beta 1 was localized to the apical membranous portion of the same epithelium. PLC-beta 3 was seen in the nucleus of the respiratory and alveolar lining epithelium as well as in the nucleus of lung fibroblasts.
Adult ; Chromatography, Agarose ; Female ; Heparin/chemistry ; Human ; Immunohistochemistry ; Isoenzymes/isolation & purification/*metabolism ; Lung/*enzymology/pathology ; Male ; Phospholipase C/isolation & purification/*metabolism

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

Antithrombin III (AT III) is the most important anti-clotting substance. Recombinant human antithrombin III (rhAT III) expressed in transgenic goat milk attracts more and more attention. Develop an effective purification route for rhAT III is vital to its industrial production. An efficient purification method was developed for the rapid purification of rhAT III by isoelectric precipitation and heparin affinity chromatography. First, casein was effectively removed by isoelectric precipitation. rhAT III was further purified by heparin affinity chromatography. In the process of heparin affinity chromatography, the effects of pH and temperature on the stability of rhAT III were studied, and the effects of operating conditions, elution gradient, flow rate and sample loaded, on the purification efficiency were also studied. Under the optimized conditions, the protein recovery of rhAT III was about 90% with purity over 99%, while its activity recovery was about 50%. Such a purification process is very simple and effective, and it would provide a valuable reference for the further scaling-up of industrial production.
Animals ; Animals, Genetically Modified ; Antithrombin III ; biosynthesis ; Chromatography, Affinity ; Female ; Goats ; Heparin ; Humans ; Mammary Glands, Animal ; metabolism ; Milk ; chemistry ; Recombinant Proteins ; biosynthesis

To investigate effects of collagen matrices by covalent incorporation of heparin and loading with huangqi injection (HI) on anagenetic capillaries, we established the chick chorioallantois model. The collagen matrices by covalent incorporation of heparin and loading with HI were placed and then the eggs were continuously incubated for 3 days. The number of capillaries in the vicinity of samples, the hemoglobin content inside the samples, the dry weight and the macroscopic observation were evaluated. We found the heparinized matrices had comparable angiogenic effects. The number of capillaries, the hemoglobin content, the expression of CD34 increased remarkably (P < 0.01). So we concluded that HI might be considered as an alternative or addition agent to promote the acidification of capillaries.
Animals ; Blood Vessels ; drug effects ; physiology ; Capillaries ; drug effects ; metabolism ; Chick Embryo ; Collagen ; administration & dosage ; chemistry ; pharmacology ; Drugs, Chinese Herbal ; administration & dosage ; pharmacology ; Heparin ; administration & dosage ; chemistry ; pharmacology ; Humans ; Injections

To investigate the effects of complex danshen solution and heparin on the changes of blood coagulation factors in rats with hemorrhagic shock, and to explore the therapy of coagulopathy by compound danshen solution, the rat model of hemorrhagic shock was set up, 40 SD rats were randomized into four groups: sham operation, shock, compound danshen solution and heparin groups, each group was composed of 10 SD rats. Plasma SFMC, TM, ATIII, D-D, t-PA, PAI levels and APTT were detected, incidences of bleeding complications between heparin and danshen group were compared. The results showed that plasma SFMC, D-D levels in shock group were higher but ATIII level in shock group was lower than that in sham operation group, compound danshen solution group and heparin group (P < 0.001), TM levels obviously increased in shock group and heparin group (P < 0.001). There was no significant difference between compound danshen solution and sham-operation groups. Plasma t-PA, D-D levels obviously increased after shock for 2 hours, PAI level reached the peak after shock for 4 hours, but t-PA decreased. After shock for 6 hours, plasma PAI descended, t-PA continually drop in, but PAI and D-D remained in higher levels. Plasma D-D level in heparin group was lower than that in shock group, t-PA level was higher than that in shock group, but there was no significant difference between in heparin and shock groups. Plasma t-PA, PAI and D-D levels in compound danshen solution group were lower than that in shock group. APTT of danshen group was lower than that of shock group and heparin group. Bleeding incidences was 30% in heparin group and 0% in danshen group, respectively. It is concluded that compound danshen solution may used to treat hypercoagulation and hyperfibrinolysis. In comparsion with heparin, danshen posses-ses advantages of safety with less bleeding complication and needs not tight monitor.
Animals ; Anticoagulants ; therapeutic use ; Blood Coagulation ; drug effects ; Blood Coagulation Factors ; metabolism ; Drugs, Chinese Herbal ; therapeutic use ; Female ; Fibrin Fibrinogen Degradation Products ; metabolism ; Heparin ; therapeutic use ; Male ; Partial Thromboplastin Time ; Phytotherapy ; Plasminogen Activator Inhibitor 1 ; blood ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Salvia miltiorrhiza ; chemistry ; Shock, Hemorrhagic ; blood ; drug therapy ; Thromboplastin ; metabolism ; Tissue Plasminogen Activator ; blood