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Search results for: Streptokinase Proteins

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#33538961   2021/02/04 To Up

Cross-linked Enzyme Aggregates of Fibrinolytic Protease BC1 Immobilized on Magnetic Chitosan Nanoparticles (CLEAs-Fib-mChi): Synthesis, Purification, and Characterization.

Bacterial fibrinolytic proteases achieved more attention in the prevention and treatment of cardiovascular diseases, so purification, characterization, and activity enhancement are of prime importance. In this study, a fibrinolytic serine metalloprotease was purified from the culture supernatant from Bacillus sp. BC1. It was purified to homogeneity by a two-step procedure with a 24-fold increase in specific activity and a 33.1% yield. It showed 28 kDa molecular weight, while its optimal pH and temperature were obtained 8 and 50-60 °C. The cross-link enzyme aggregates of this fibrinolytic BC1 successfully immobilized on magnetic chitosan nanoparticles. A 52% activity enhancement was obtained by immobilized enzyme at pH 6.0, compared to free protease. K values of the free and immobilized proteases were obtained about 0.638 and 0.61 mg/ml, respectively. The free and immobilized enzymes did not show any activity concerning transferrin, γ-globulins, and hemoglobin, as blood plasma proteins. The in vitro blood clot lysis test of the free and immobilized proteases showed a maximum of 42 and 50% clot lysis, which was comparatively higher than that revealed by streptokinase and heparin at the same condition. These results indicated that the free and immobilized proteases have the potential to be effective fibrinolytic agents.
Shima Khankari, Arastoo Badoei-Dalfard, Zahra Karami

1066 related Products with: Cross-linked Enzyme Aggregates of Fibrinolytic Protease BC1 Immobilized on Magnetic Chitosan Nanoparticles (CLEAs-Fib-mChi): Synthesis, Purification, and Characterization.

11 mg100 ug10ml 500 ml 25ml 1 mg500 µl1x96 well plate200ul100ug

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#33495187   2021/01/25 To Up

Streptokinase in a COVID-19-positive patient with STEMI in a PPCI centre: a local experience.

Primary percutaneous coronary intervention is the recommended modality of treatment for acute ST-elevation myocardial infarction (STEMI). However, different countries now have different consensus about treatment of patients with STEMI during the COVID-19 pandemic. In this report, we describe a case of SARS-CoV-2-positive patient admitted with pneumonia. During hospital stay in COVID-19 designated special care, the patient developed inferoposterior wall myocardial infarction (MI) without haemodynamic instability and was treated successfully with thrombolytics (streptokinase) without any severe complications. To decrease the risk of in-hospital exposure to COVID-19 infection among the staff, in circumstances where there is no negative-pressure catheterisation laboratory and there is shortage in medical staff, thrombolytics can be used as a modality of treatment in low-risk, haemodynamically stable MI during this pandemic, as recommended by different cardiac societies. However, this needs further studies in order to reach local and international consensus.
Nasir Rahman, Ihsan Ullah, Ghufran Adnan

2373 related Products with: Streptokinase in a COVID-19-positive patient with STEMI in a PPCI centre: a local experience.

20 100.00 ug20 100 μg0.1mg100 μg4 Membranes/Box100 μg100 μg

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#33228554   2020/11/23 To Up

Comparison of QT dispersion in patients with ST elevation acute myocardial infarction (STEMI) before and after treatment by streptokinase versus primary percutaneous coronary intervention (PCI).

QT dispersion (QTD) represents inhomogeneous ventricular repolarization such that an increased QTD may predispose the heart to malignant ventricular arrhythmias (VAs). This study was conducted to compare QTD in patients with ST-elevation myocardial infarction (STEMI) before and after treatment by streptokinase (SK) versus primary percutaneous coronary intervention (PCI).
Abbas Valizadeh, Sahar Soltanabadi, Saeed Koushafar, Maryam Rezaee, Reza Jahankhah

1432 related Products with: Comparison of QT dispersion in patients with ST elevation acute myocardial infarction (STEMI) before and after treatment by streptokinase versus primary percutaneous coronary intervention (PCI).

100 μg20 ul

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#33208461   2020/11/18 To Up

Streptococcus co-opts a conformational lock in human plasminogen to facilitate streptokinase cleavage and bacterial virulence.

Virulent strains of Streptococcus pyogenes (GAS) recruit host single-chain human plasminogen (hPg) to the cell surface - where in the case of Pattern D strains of GAS - hPg binds directly to the cells through a surface receptor, plasminogen-binding group A streptococcal M-protein (PAM).  The coinherited Pattern D GAS-secreted streptokinase (SK2b) then accelerates cleavage of hPg at the R561-V562 peptide bond, resulting in the disulfide-linked two-chain protease, plasmin (hPm).  hPm localizes on the bacterial surface, assisting bacterial dissemination via proteolysis of host defense proteins.  Studies using isolated domains from PAM and hPg revealed that the A-domain of PAM binds to the hPg kringle-2 module (K2hPg), but how this relates to the function of the full-length proteins is unclear.  Herein, we use intact proteins to show that the lysine binding site (LBS) of K2hPg is a major determinant of the activation-resistant T-conformation of hPg.  The binding of PAM to the LBS of K2hPg relaxes the conformation of hPg, leading to a greatly enhanced activation rate of hPg by SK2b.  Domain swapping between hPg and mPg emphasizes the importance of the Pg latent heavy chain (residues 1-561) in PAM binding and shows that while SK2b binds to both hPg and mPg, the activation properties of SK are strictly attributed to the serine protease domain (residues 562-791) of hPg.  Overall, these data show that native hPg is locked in an activation-resistant conformation that is relaxed upon its direct binding to PAM, allowing hPm to form and provide GAS cells with a proteolytic surface.
Yetunde A Ayinuola, Teresa Brito-Robinson, Olawole Ayinuola, Julia E Beck, Diana Cruz-Topete, Shaun W Lee, Victoria A Ploplis, Francis J Castellino

1456 related Products with: Streptococcus co-opts a conformational lock in human plasminogen to facilitate streptokinase cleavage and bacterial virulence.

25 100 1 kit(96 Wells)100 μg100 μg100 μg100 μg50 100 μg100 μg200 100 μg

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#33167101   // To Up

[Thrombolytic effects of recombinant staphylokinase on coronary thrombosis in miniature pigs].

To evaluate the thrombolytic effects of recombinant staphylokinase and compare it with those of recombinant streptokinase.
Guang Li, Xiao-Lan Fang, Zhong Ren, Ke-Qiang Li, Song-Hui Zhou, Dao-Qi Hu, Gang-Qiang Wu, Tai-Lin Wang, Wei-Ping Li

1160 related Products with: [Thrombolytic effects of recombinant staphylokinase on coronary thrombosis in miniature pigs].

10 100 5 2 2 2 2

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#32343811   // To Up

Excessively activated plasminogen in human plasma cleaves VWF multimers and reduces collagen-binding activity.

Plasmin (Pm) is a serine protease that can dissolve fibrin clots. Several possible functions of Pm in blood other than fibrinolysis have been proposed. To explore the effects of Pm on primary haemostasis, we evaluated the cleavage of von Willebrand factor multimers (VWFMs) in human plasma by streptokinase (SK)-activated plasminogen (Pg) and the binding ability of the digested VWFMs to collagen. SK-activated Pg and ADAMTS13 (a VWF-cleaving enzyme) in human plasma cleaved VWFMs in conformation-dependent manners through dialysis to the urea-containing buffer. However, VWFMs in human plasma under vortex-based shear stress were cleaved by SK-activated Pg but not by ADAMTS13. These results suggested that the VWFM-cleavage sites in human plasma are exposed to some extent by vortex-based shear stress for Pm but not for ADAMTS13. Additionally, we revealed that cleavage by SK-activated Pg reduced VWFMs' binding ability to collagen, and VWFMs in human plasma were cleaved by Pm at several sites. These results suggest that SK-activated Pg degrades VWFMs, reduces their binding abilities to collagen and affects primary haemostasis. Because excessive Pg activation can degrade fibrinogen/fibrin, we propose that SK-activated Pg in blood may cause impaired primary and secondary haemostasis.
Kenshi Togashi, Satoshi Suzuki, Sae Morita, Yuki Ogasawara, Yasutada Imamura, Yongchol Shin

2718 related Products with: Excessively activated plasminogen in human plasma cleaves VWF multimers and reduces collagen-binding activity.

96T1 mg1mg10.05 mg48 assays100 μg96T1 mg1 Gram1.0mg

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#32304282   2020/05/10 To Up

Novel Streptococcus equi strains causing strangles outbreaks in Arabian horses in Egypt.

Strangles displays a major challenge to veterinary medicine worldwide. However, no data on Streptococcus equi subsp. equi (S. equi) M protein alleles have been reported so far from Arabian horses. We report here for the first time the S. equi SeM alleles causing strangles in Arabian horses, and the associated risk factors for the disease. Duplicate samples from one hundred Arabian horses with acute strangles in confirmed outbreaks and sporadic cases were analysed by phenotypic methods and multiplex polymerase chain reaction (PCR) targeting streptokinase precursor, seeI and sodA genes. PCR and sequencing of S. equi SeM gene were employed for strains typing, and the four superantigens were determined among the allelic variants. Direct-sample PCR confirmed and highly positively correlated (r = .85) with the phenotypic results, and detected S. equi in five samples more than the conventional culture. A combination of multiplex PCR from samples and culture could successfully identify S. equi (92%), S. zooepidemicus (5%) and S. equisimilis (3%). SeM typing demonstrated five SeM alleles, including four previously unidentified alleles that were deposited in the PubMLST-SeM database. SeM-139 and SeM-141 are related to some strains that were recently recovered from donkeys in China. SeM-140 and SeM-199 are related to a group of alleles from horses in Europe. Variation in the presence of seeM, seeH and seeL superantigens was found across the four novel alleles without interference with the severity of strangles and clinical presentation seen in different outbreaks. Horse age was the most important factor in developing strangles, followed by seasonality and the diagnosis of strangles in the previous year. These new findings comprise a significant contribution to the horse industry through the identification of novel S. equi SeM types that may bolster measures for strangles control as the identified SeM alleles will certainly help in the development of SeM-containing vaccine.
Yasmine H Tartor, El-Sayed Y El-Naenaeey, Nesreen M Gharieb, Wessam S Ali, Ahmed M Ammar

2937 related Products with: Novel Streptococcus equi strains causing strangles outbreaks in Arabian horses in Egypt.

25

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#32244484   2020/03/31 To Up

Deriving Immune Modulating Drugs from Viruses-A New Class of Biologics.

Viruses are widely used as a platform for the production of therapeutics. Vaccines containing live, dead and components of viruses, gene therapy vectors and oncolytic viruses are key examples of clinically-approved therapeutic uses for viruses. Despite this, the use of virus-derived proteins as natural sources for immune modulators remains in the early stages of development. Viruses have evolved complex, highly effective approaches for immune evasion. Originally developed for protection against host immune responses, viral immune-modulating proteins are extraordinarily potent, often functioning at picomolar concentrations. These complex viral intracellular parasites have "performed the R&D", developing highly effective immune evasive strategies over millions of years. These proteins provide a new and natural source for immune-modulating therapeutics, similar in many ways to penicillin being developed from mold or streptokinase from bacteria. Virus-derived serine proteinase inhibitors (serpins), chemokine modulating proteins, complement control, inflammasome inhibition, growth factors (e.g., viral vascular endothelial growth factor) and cytokine mimics (e.g., viral interleukin 10) and/or inhibitors (e.g., tumor necrosis factor) have now been identified that target central immunological response pathways. We review here current development of virus-derived immune-modulating biologics with efficacy demonstrated in pre-clinical or clinical studies, focusing on pox and herpesviruses-derived immune-modulating therapeutics.
Jordan R Yaron, Liqiang Zhang, Qiuyun Guo, Michelle Burgin, Lauren N Schutz, Enkidia Awo, Lyn Wise, Kurt L Krause, Cristhian J Ildefonso, Jacek M Kwiecien, Michael Juby, Masmudur M Rahman, Hao Chen, Richard W Moyer, Antonio Alcami, Grant McFadden, Alexandra R Lucas

1404 related Products with: Deriving Immune Modulating Drugs from Viruses-A New Class of Biologics.

1 mg500 100ug Lyophilized0.25 mg0.1 mg200 100ug Lyophilized0.1 mg1mg0.25 mg0.25 mg100ug Lyophilized

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