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Wu X, Yun Z, Su N, Zhao L, Zhang H, Zhang M, Wu Q, Zhang C, Xing XH. Characterization of maltose-binding protein-fused heparinases with enhanced thermostability by application of rigid and flexible linkers. Biotechnol Appl Biochem 2024. [PMID: 39072851 DOI: 10.1002/bab.2642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 07/09/2024] [Indexed: 07/30/2024]
Abstract
Heparinases, including heparinases I-III (HepI, HepII, and HepIII, respectively), are important tools for producing low-molecular-weight heparin, an improved anticoagulant. The poor thermostability of heparinases significantly hinders their industrial and laboratory applications. To improve the thermostability of heparinases, we applied a rigid linker (EAAAK)5 (R) and a flexible linker (GGGGS)5 (F) to fuse maltose-binding protein (MBP) and HepI, HepII, and HepIII from Pedobacter heparinus, replacing the original linker from the plasmid pMAL-c2X. Compared with their parental fusion protein, MBP-fused HepIs, HepIIs, and HepIIIs with linkers (EAAAK)5 or (GGGGS)5 all displayed enhanced thermostability (half-lives at 30°C: 242%-464%). MBP-fused HepIs and HepIIs exhibited higher specific activity (127%-324%), whereas MBP-fused HepIIIs displayed activity similar to that of their parental fusion protein. Kinetics analysis revealed that MBP-fused HepIIs showed a significantly decreased affinity toward heparin with increased Km values (397%-480%) after the linker replacement, whereas the substrate affinity did not change significantly for MBP-fused HepIs and HepIIIs. Furthermore, it preliminarily appeared that the depolymerization mechanism of these fusion proteins may not change after linker replacement. These findings suggest the superior enzymatic properties of MBP-fused heparinases with suitable linker designs and their potential for the bioproduction of low-molecular-weight heparin.
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Affiliation(s)
- Xi Wu
- Sub-Institute of Agriculture and Food Standardization, China National Institute of Standardization, Beijing, China
| | - Zhenyu Yun
- Sub-Institute of Agriculture and Food Standardization, China National Institute of Standardization, Beijing, China
| | - Nan Su
- MOE Key Lab of Industrial Biocatalysis, Institute of Biochemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing, China
| | - Lin Zhao
- Sub-Institute of Agriculture and Food Standardization, China National Institute of Standardization, Beijing, China
| | - Hui Zhang
- MOE Key Lab of Industrial Biocatalysis, Institute of Biochemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing, China
| | - Mengyan Zhang
- Sub-Institute of Agriculture and Food Standardization, China National Institute of Standardization, Beijing, China
| | - Qi Wu
- Sub-Institute of Agriculture and Food Standardization, China National Institute of Standardization, Beijing, China
| | - Chong Zhang
- MOE Key Lab of Industrial Biocatalysis, Institute of Biochemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing, China
| | - Xin-Hui Xing
- MOE Key Lab of Industrial Biocatalysis, Institute of Biochemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing, China
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Venezia B, Morris DC, Gavriilidis A. Taylor‐vortex membrane reactor for continuous gas‐liquid reactions. AIChE J 2022. [DOI: 10.1002/aic.17880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Baldassarre Venezia
- Department of Chemical Engineering University College London, Torrington Place London UK
| | - David C. Morris
- Autichem Ltd, Unit 4, Gatewarth Industrial Estate Barnard Street Warrington WA5 1DD
| | - Asterios Gavriilidis
- Department of Chemical Engineering University College London, Torrington Place London UK
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Gao LW, Zhu HT, Liu CY, Lv ZX, Fan XM, Zhang YW. A highly active heparinase I from Bacteroides cellulosilyticus: Cloning, high level expression, and molecular characterization. PLoS One 2020; 15:e0240920. [PMID: 33079966 PMCID: PMC7575093 DOI: 10.1371/journal.pone.0240920] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 10/05/2020] [Indexed: 11/19/2022] Open
Abstract
As one of the most extensively studied glycosaminoglycan lyases, heparinase I has been used in producing low or ultra-low molecular weight heparin. Its' important applications are to neutralize the heparin in human blood and analyze heparin structure in the clinic. However, the low productivity and activity of the enzyme have greatly hindered its applications. In this study, a novel Hep-I from Bacteroides cellulosilyticus (BcHep-I) was successfully cloned and heterologously expressed in E. coli BL21 (DE3) as a soluble protein. The molecular mass and isoelectric point (pI) of the enzyme are 44.42 kDa and 9.02, respectively. And the characterization of BcHep-I after purified with Ni-NTA affinity chromatography suggested that it is a mesophilic enzyme. BcHep-I can be activated by 1 mM Ca2+, Mg2+, and Mn2+, while severely inhibited by Zn2+, Co2+, and EDTA. The specific activity of the enzyme was 738.3 U·mg-1 which is the highest activity ever reported. The Km and Vmax were calculated as 0.17 mg·mL-1 and 740.58 U·mg-1, respectively. Besides, the half-life of 300 min at 30°C showed BcHep-I has practical applications. Homology modeling and substrate docking revealed that Gln15, Lys74, Arg76, Lys104, Arg149, Gln208, Tyr336, Tyr342, and Lys338 were mainly involved in the substrate binding of Hep-I, and 11 hydrogen bonds were formed between heparin and the enzyme. These results indicated that BcHep-I with high activity has great potential applications in the industrial production of heparin, especially in the clinic to neutralize heparin.
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Affiliation(s)
- Li-Wei Gao
- The People’s Hospital of Danyang, Affiliated Danyang Hospital of Nantong University, Danyang, Jiangsu Province, China
| | - Hong-Tao Zhu
- The People’s Hospital of Danyang, Affiliated Danyang Hospital of Nantong University, Danyang, Jiangsu Province, China
| | - Cai-Yun Liu
- School of Pharmacy, Jiangsu University, Zhenjiang, People’s Republic of China
| | - Zhi-Xiang Lv
- The People’s Hospital of Danyang, Affiliated Danyang Hospital of Nantong University, Danyang, Jiangsu Province, China
| | - Xiao-Man Fan
- School of Pharmacy, Jiangsu University, Zhenjiang, People’s Republic of China
| | - Ye-Wang Zhang
- School of Pharmacy, Jiangsu University, Zhenjiang, People’s Republic of China
- * E-mail:
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Liu CY, Su WB, Guo LB, Zhang YW. Cloning, expression, and characterization of a novel heparinase I from Bacteroides eggerthii. Prep Biochem Biotechnol 2020; 50:477-485. [PMID: 31900079 DOI: 10.1080/10826068.2019.1709977] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Heparinase I (Hep I) specifically degrades heparin to oligosaccharide or unsaturated disaccharide and has been widely used in preparation of low molecular weight heparin (LMWH). In this work, a novel Hep I from Bacteroides eggerthii VPI T5-42B-1 was cloned and overexpressed in Escherichia coli BL21 (DE3). The enzyme has specific activity of 480 IU·mg-1 at the optimal temperature and pH of 30 °C and pH 7.5, and the Km and Vmax were 3.6 mg·mL-1 and 647.93 U·mg-1, respectively. The Hep I has good stability with t1/2 values of 350 and 60 min at 30 and 37 °C, respectively. And it showed a residual relative activity of 70.8% after 21 days incubation at 4 °C. Substrate docking study revealed that Lys99, Arg101, Gln241, Lys270, Asn275, and Lys292 were mainly involved in the substrate binding of Hep I. The shorter hydrogen bonds formed between heparin and these residues suggested the higher specific activity of BeHep I. And the minimum conformational entropy value of 756 J·K-1 provides an evidence for the improved stability of this enzyme. This Hep I could be of interest in the industrial preparation of LMWH for its high specific activity and good stability.
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Affiliation(s)
- Cai-Yun Liu
- School of Pharmacy, Jiangsu University, Zhenjiang, People's Republic of China
| | - Wen-Bin Su
- School of Pharmacy, Jiangsu University, Zhenjiang, People's Republic of China
| | - Li-Bin Guo
- School of Pharmacy, Jiangsu University, Zhenjiang, People's Republic of China
| | - Ye-Wang Zhang
- School of Pharmacy, Jiangsu University, Zhenjiang, People's Republic of China
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Zhang C, Yang BC, Liu WT, Li ZY, Song YJ, Zhang TC, Luo XG. Structure-based engineering of heparinase I with improved specific activity for degrading heparin. BMC Biotechnol 2019; 19:59. [PMID: 31399136 PMCID: PMC6688311 DOI: 10.1186/s12896-019-0553-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Accepted: 07/31/2019] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Heparinase I from Pedobacter heparinus (Ph-HepI), which specifically cleaves heparin and heparan sulfate, is one of the most extensively studied glycosaminoglycan lyases. Enzymatic degradation of heparin by heparin lyases not only largely facilitates heparin structural analysis but also showed great potential to produce low-molecular-weight heparin (LMWH) in an environmentally friendly way. However, industrial applications of Ph-HepI have been limited by their poor yield and enzyme activity. In this work, we improve the specific enzyme activity of Ph-HepI based on homology modeling, multiple sequence alignment, molecular docking and site-directed mutagenesis. RESULTS Three mutations (S169D, A259D, S169D/A259D) exhibited a 50.18, 40.43, and 122.05% increase in the specific enzyme activity and a 91.67, 108.33, and 75% increase in the yield, respectively. The catalytic efficiencies (kcat/Km) of the mutanted enzymes S169D, A259D, and S169D/A259D were higher than those of the wild-type enzyme by 275, 164, and 406%, respectively. Mass spectrometry and activity detection showed the enzyme degradation products were in line with the standards of the European Pharmacopoeia. Protein structure analysis showed that hydrogen bonds and ionic bonds were important factors for improving specific enzyme activity and yield. CONCLUSIONS We found that the mutant S169D/A259D had more industrial application value than the wild-type enzyme due to molecular modifications. Our results provide a new strategy to increase the catalytic efficiency of other heparinases.
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Affiliation(s)
- Chuan Zhang
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education & Tianjin Key Lab of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China.,State Key Laboratory of Food Nutrition and Safety, Tianjin, 300457, China
| | - Bao-Cheng Yang
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education & Tianjin Key Lab of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China.,State Key Laboratory of Food Nutrition and Safety, Tianjin, 300457, China
| | - Wen-Ting Liu
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education & Tianjin Key Lab of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China.,State Key Laboratory of Food Nutrition and Safety, Tianjin, 300457, China
| | - Zhong-Yuan Li
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education & Tianjin Key Lab of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China.,State Key Laboratory of Food Nutrition and Safety, Tianjin, 300457, China
| | - Ya-Jian Song
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education & Tianjin Key Lab of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China.,State Key Laboratory of Food Nutrition and Safety, Tianjin, 300457, China
| | - Tong-Cun Zhang
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education & Tianjin Key Lab of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China.,State Key Laboratory of Food Nutrition and Safety, Tianjin, 300457, China
| | - Xue-Gang Luo
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education & Tianjin Key Lab of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China. .,State Key Laboratory of Food Nutrition and Safety, Tianjin, 300457, China.
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Abstract
Dextran aldehyde (dexOx), resulting from the periodate oxidative cleavage of 1,2-diol moiety inside dextran, is a polymer that is very useful in many areas, including as a macromolecular carrier for drug delivery and other biomedical applications. In particular, it has been widely used for chemical engineering of enzymes, with the aim of designing better biocatalysts that possess improved catalytic properties, making them more stable and/or active for different catalytic reactions. This polymer possesses a very flexible hydrophilic structure, which becomes inert after chemical reduction; therefore, dexOx comes to be highly versatile in a biocatalyst design. This paper presents an overview of the multiple applications of dexOx in applied biocatalysis, e.g., to modulate the adsorption of biomolecules on carrier surfaces in affinity chromatography and biosensors design, to serve as a spacer arm between a ligand and the support in biomacromolecule immobilization procedures or to generate artificial microenvironments around the enzyme molecules or to stabilize multimeric enzymes by intersubunit crosslinking, among many other applications.
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Sha Y, Fritz J, Klemm T, Ripperger S. Untersuchung der Strömung im Taylor-Couette-System bei geringen Spaltbreiten. CHEM-ING-TECH 2016. [DOI: 10.1002/cite.201500009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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8
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Polycation-induced benzoperylene probe excimer formation and the ratiometric detection of heparin and heparinase. Biosens Bioelectron 2016; 75:404-10. [DOI: 10.1016/j.bios.2015.08.068] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 08/20/2015] [Accepted: 08/29/2015] [Indexed: 01/03/2023]
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9
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CFD simulation of shear flow and mixing in a Taylor–Couette reactor with variable cross-section inner cylinders. POWDER TECHNOL 2015. [DOI: 10.1016/j.powtec.2015.04.050] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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10
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Wu J, Zhou L, Zhang H, Guo J, Mei X, Zhang C, Yuan J, Xing XH. Direct affinity immobilization of recombinant heparinase I fused to maltose binding protein on maltose-coated magnetic nanoparticles. Biochem Eng J 2014. [DOI: 10.1016/j.bej.2014.05.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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11
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Zhang Y, Lapidos KA, Gal-Moscovici A, Sprague SM, Ameer GA. A receptor-based bioadsorbent to target advanced glycation end products in chronic kidney disease. Artif Organs 2013; 38:474-83. [PMID: 24206165 DOI: 10.1111/aor.12203] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The accumulation of advanced glycation end products (AGEs) has been reported to be a major contributor to chronic systemic inflammation. AGEs are not efficiently removed by hemodialysis or the kidney of a chronic kidney disease (CKD) patient. The goal of this study was to develop a receptor for AGEs (RAGE)-based bioadsorbent device that was capable of removing endogenous AGEs from human blood. The extracellular domain of RAGE was immobilized onto agarose beads to generate the bioadsorbent. The efficacy of AGE removal from saline, serum, and whole blood; biological effects of AGE reduction; and hemocompatibility and stability of the bioadsorbent were investigated. The bioadsorbent bound AGE-modified bovine serum albumin (AGE-BSA) with a binding capacity of 0.73 ± 0.07 mg AGE-BSA/mL bioadsorbent. The bioadsorbent significantly reduced the concentration of total AGEs in serum isolated from end-stage kidney disease patients by 57%. AGE removal resulted in a significant reduction of vascular cell adhesion molecule-1 expression in human endothelial cells and abolishment of osteoclast formation in osteoclast progenitor cells. A hollow fiber device loaded with bioadsorbent-reduced endogenous AGEs from recirculated blood to 36% of baseline levels with no significant changes in total protein or albumin concentration. The bioadsorbent maintained AGE-specific binding capacity after freeze-drying and storage for 1 year. This approach provides the foundation for further development of soluble RAGE-based extracorporeal therapies to selectively deplete serum AGEs from human blood and decrease inflammation in patients with diabetes and/or CKD.
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Affiliation(s)
- Yangrong Zhang
- Biomedical Engineering Department, Northwestern University, Evanston, IL, USA
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12
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Combination of site-directed mutagenesis and calcium ion addition for enhanced production of thermostable MBP-fused heparinase I in recombinant Escherichia coli. Appl Microbiol Biotechnol 2012; 97:2907-16. [PMID: 22588503 DOI: 10.1007/s00253-012-4145-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 04/13/2012] [Accepted: 04/26/2012] [Indexed: 10/28/2022]
Abstract
Heparinase I (HepI), which specifically cleaves heparin and heparan sulfate, is one of the most extensively studied glycosaminoglycan lyases. Low productivity of HepI has largely hindered its industrial and pharmaceutical applications. Loss of bacterial HepI enzyme activity through poor thermostability during its expression and purification process in production can be an important issue. In this study, using a thermostabilization strategy combining site-directed mutagenesis and calcium ion addition during its production markedly improved the yield of maltose-binding protein-fused HepI (MBP-HepI) from recombinant Escherichia coli. Substitution of Cys297 to serine in MBP-HepI offered a 30.6% increase in the recovered total enzyme activity due to a mutation-induced thermostabilizing effect. Furthermore, upon addition of Ca2+ as a stabilizer at optimized concentrations throughout its expression, extraction, and purification process, purified mutant MBP-HepI showed a specific activity of 56.3 IU/mg, 206% higher than that of the wild type obtained without Ca2+ addition, along with a 177% increase in the recovered total enzyme activity. The enzyme obtained through this novel approach also exhibited significantly enhanced thermostability, as indicated by both experimental data and the kinetic modeling. High-yield production of thermostable MBP-HepI using the present system will facilitate its applications in laboratory-scale heparin analysis as well as industrial-scale production of low molecular weight heparin as an improved anticoagulant substitute.
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Chen S, Ye F, Chen Y, Chen Y, Zhao H, Yatsunami R, Nakamura S, Arisaka F, Xing XH. Biochemical analysis and kinetic modeling of the thermal inactivation of MBP-fused heparinase I: Implications for a comprehensive thermostabilization strategy. Biotechnol Bioeng 2011; 108:1841-51. [DOI: 10.1002/bit.23144] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Revised: 03/07/2011] [Accepted: 03/14/2011] [Indexed: 11/12/2022]
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14
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Varghese MS, Hildebrandt D, Glasser D, Rubin D, Crowther N. The effect of poly-l-lysine/alginate bead membrane characteristics on the absorption of heparin. ACTA ACUST UNITED AC 2009; 37:13-22. [DOI: 10.1080/10731190802664171] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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15
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Varghese MS, Hildebrandt D, Glasser D, Crowther NJ, Rubin DM. Efficiency of Polymer Beads in the Removal of Heparin: Toward the Development of a Novel Reactor. ACTA ACUST UNITED AC 2009; 34:419-32. [PMID: 16818415 DOI: 10.1080/10731190600769800] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Administration of heparin during extracorporeal procedures increases the risk of haemorrhage. Various reactor designs, including the use of heparinase and poly-L-lysine. HBr hollow fiber, have been investigated for the removal of heparin prior to the blood being returned to the patient; however, none of them have been implemented clinically. In this paper it is proposed that beads made from poly-L-lysine/alginate can be used to remove the heparin. The aim of this work is to perform the necessary experiments in order to get the information required to design a heparin removal reactor that uses these beads. The experiments are aimed at measuring the removal rates of heparin by the beads, testing the efficiency of the beads to remove heparin, determining repeatability and identifying factors that could influence the removal rate. Batch rate experiments using poly-L-lysine/alginate beads in saline solutions were performed to investigate the removal rate of heparin. The results, which indicate that heparin is efficiently removed, may lead to improved bioreactor designs.
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Affiliation(s)
- M Sunil Varghese
- School of Process and Materials Engineering, University of the Witwatersrand, Johannesburg, South Africa
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16
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Soos M, Wu H, Morbidelli M. Taylor-Couette unit with a lobed inner cylinder cross section. AIChE J 2007. [DOI: 10.1002/aic.11153] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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17
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Ameer GA, Grovender EA, Obradovic B, Cooney CL, Langer R. RTD analysis of a novel Taylor-Couette flow device for blood detoxification. AIChE J 2006. [DOI: 10.1002/aic.690450320] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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18
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Grovender EA, Cooney CL, Langer R, Ameer GA. Immunoadsorption model for a novel fluidized-bed blood detoxification device. AIChE J 2006. [DOI: 10.1002/aic.690481025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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19
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Racina A, Kind M, Požarnik M. Experimentelle Untersuchung zur Makro- und Mesovermischung im Taylor-Couette-Reaktor mittels laserinduzierter Fluoreszenz (LIF). CHEM-ING-TECH 2005. [DOI: 10.1002/cite.200500040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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20
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Resende MM, Vieira PG, Sousa Jr R, Giordano RLC, Giordano RC. Estimation of mass transfer parameters in a Taylor-Couette-Poiseuille heterogeneous reactor. BRAZILIAN JOURNAL OF CHEMICAL ENGINEERING 2004. [DOI: 10.1590/s0104-66322004000200006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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21
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Resende MM, Sousa R, Tardioli PW, Giordano RLC, Giordano RC. Enzymatic tailor-made proteolysis of whey in a vortex flow reactor. AIChE J 2004. [DOI: 10.1002/aic.10241] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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22
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Körfer S, Klaus S, Mottaghy K. Application of Taylor vortices in hemocompatibility investigations. Int J Artif Organs 2003; 26:331-8. [PMID: 12757032 DOI: 10.1177/039139880302600408] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Artificial organs, implants and extracorporeal circulation affect the physiological flow characteristics of blood as a liquid organ. These artificial systems consist of a wide variety of biomaterials with different geometries and, therefore, with their own flow properties. Secondary flow also occurs in extra--as well as in intracorporeal circulation. METHODS In order to investigate the influence of vortical flow conditions a modified Taylor-Couette system was introduced. It consisted of two coaxial cylinders whose surfaces were the target of investigation. The annular gap was filled with donor blood shear and secondary flows were produced by rotating the inner cylinder. Platelet activation and protein adsorption were investigated as markers for thrombogenicity. RESULTS At shear rates high enough to establish stable Taylor vortices (G > or = 550 s(-1)) significant differences between vortical Taylor flow and steady laminar flow were detected. At shear rates of G > or = 550 s(-1) laminar flow caused a significantly higher platelet drop and PF4 release when compared to Taylor vortex flow. Also protein adsorption per square unit was significantly higher for laminar flow. CONCLUSIONS Based on the present data we conclude that vortical flow patterns lead to an accumulation of platelets and plasma proteins in the vortex center and therefore to a decreased probability of contact between platelets and material surfaces. It can be concluded that a preactivation of the platelets circulating in extracorporeal circuits can be manifested downstream in other geometrical configurations and flow conditions.
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Affiliation(s)
- S Körfer
- Institute for Physiology, and Interdisciplinary Center for Clinical Research (IZKF) BIOMAT, RWTH Aachen, Germany.
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23
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Ameer GA, Grovender EA, Ploegh H, Ting D, Owen WF, Rupnick M, Langer R. A novel immunoadsorption device for removing beta2-microglobulin from whole blood. Kidney Int 2001; 59:1544-50. [PMID: 11260419 DOI: 10.1046/j.1523-1755.2001.0590041544.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND High plasma levels of beta2-microglobulin (beta2m) have been implicated in the formation of the severely destructive and potentially fatal amyloid deposits that are characteristic of dialysis-related amyloidosis (DRA). Conventional renal replacement technologies remove insufficient quantities of beta2m to normalize plasma levels. This limitation arises because of nonspecific adsorptive qualities and reliance on size exclusion, which can also remove other middle molecular weight proteins. These nonspecific approaches also make it difficult to evaluate the role and contribution of middle molecular weight molecules to the pathology of DRA and other morbidities of end-stage renal disease. A high-affinity and biologically specific approach could target a protein, prevent a significant loss of other important molecules, and improve the apparent adsorption rate within an extracorporeal device. METHODS Agarose-immobilized murine anti-human beta2m monoclonal antibodies were used in a Vortex Flow Plasmapheretic Reactor (VFPR) to remove donor baseline and controlled amounts of recombinant beta2m from human blood in vitro. The extracorporeal circuit was hemoperfused at 200 mL/min for two hours. RESULTS The immunoadsorptive media had a binding site density of 30 microg beta2m per mL of settled gel. The VFPR cleared baseline quantities of donor beta2m below detectable limits of the assay. The experiments with higher initial beta2m concentrations reached an equilibrium concentration within 20 minutes, corresponding to a 92% clearance. No deleterious hemocompatibility issues were observed (complete blood count, total protein, and plasma free hemoglobin). CONCLUSIONS The adsorptive kinetics of the VFPR are optimal for the conditions used and support the use of immunoadsorption for the removal of beta2m.
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Affiliation(s)
- G A Ameer
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, USA.
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Shriver Z, Sundaram M, Venkataraman G, Fareed J, Linhardt R, Biemann K, Sasisekharan R. Cleavage of the antithrombin III binding site in heparin by heparinases and its implication in the generation of low molecular weight heparin. Proc Natl Acad Sci U S A 2000; 97:10365-70. [PMID: 10984532 PMCID: PMC27030 DOI: 10.1073/pnas.97.19.10365] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Heparin has been used as a clinical anticoagulant for more than 50 years, making it one of the most effective pharmacological agents known. Much of heparin's activity can be traced to its ability to bind antithrombin III (AT-III). Low molecular weight heparin (LMWH), derived from heparin by its controlled breakdown, maintains much of the antithrombotic activity of heparin without many of the serious side effects. The clinical significance of LMWH has highlighted the need to understand and develop chemical or enzymatic means to generate it. The primary enzymatic tools used for the production of LMWH are the heparinases from Flavobacterium heparinum, specifically heparinases I and II. Using pentasaccharide and hexasaccharide model compounds, we show that heparinases I and II, but not heparinase III, cleave the AT-III binding site, leaving only a partially intact site. Furthermore, we show herein that glucosamine 3-O sulfation at the reducing end of a glycosidic linkage imparts resistance to heparinase I, II, and III cleavage. Finally, we examine the biological and pharmacological consequences of a heparin oligosaccharide that contains only a partial AT-III binding site. We show that such an oligosaccharide lacks some of the functional attributes of heparin- and heparan sulfate-like glycosaminoglycans containing an intact AT-III site.
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Affiliation(s)
- Z Shriver
- Division of Bioengineering and Environmental Health, Harvard-Massachusetts Institute of Technology, Division of Health Sciences and Technology, Cambridge, MA 02139, USA
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Giordano R, Giordano R, Prazeres D, Cooney C. Analysis of a Taylor–Poiseuille vortex flow reactor — II: reactor modeling and performance assessment using glucose-fructose isomerization as test reaction. Chem Eng Sci 2000. [DOI: 10.1016/s0009-2509(00)00052-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Giordano RL, Giordano RC, Cooney CL. Performance of a continuous Taylor–Couette–Poiseuille vortex flow enzymic reactor with suspended particles. Process Biochem 2000. [DOI: 10.1016/s0032-9592(00)00143-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Ameer GA, Raghavan S, Sasisekharan R, Harmon W, Cooney CL, Langer R. Regional heparinization via simultaneous separation and reaction in a novel Taylor-Couette flow device. Biotechnol Bioeng 1999. [DOI: 10.1002/(sici)1097-0290(19990605)63:5%3c618::aid-bit12%3e3.0.co;2-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Ameer GA, Raghavan S, Sasisekharan R, Harmon W, Cooney CL, Langer R. Regional heparinization via simultaneous separation and reaction in a novel Taylor-Couette flow device. Biotechnol Bioeng 1999. [DOI: 10.1002/(sici)1097-0290(19990605)63:5<618::aid-bit12>3.0.co;2-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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