scholarly journals Purification of plant-derived anti-virus mAb through optimized pH conditions for coupling between protein A and epoxy-activated beads

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6828
Author(s):  
Ilchan Song ◽  
Yang Joo Kang ◽  
Su-Lim Choi ◽  
Dalmuri Han ◽  
Deuk-Su Kim ◽  
...  
Keyword(s):  
Protein A ◽  
Leaf Tissue ◽  
Positive Control ◽  
Total Soluble Protein ◽  
Fresh Leaf ◽  
Agarose Beads ◽  
Sds Page ◽  
Ph Conditions ◽  
Fluorescent Focus ◽  
Mab Production

The main goal of this research was to determine optimum pH conditions for coupling between protein A and epoxy-activated Sepharose beads for purification of monoclonal antibodies (mAbs) expressed in plants. To confirm the effect of pH conditions on purification efficacy, epoxy-activated agarose beads were coupled to protein A under the pH conditions of 8.5, 9.5, 10.5, and 11.5 (8.5R, 9.5R, 10.5R, and 11.5R, respectively). A total of 300 g of fresh leaf tissue of transgenic Arabidopsis expressing human anti-rabies mAb (mAbP) SO57 were harvested to isolate the total soluble protein (TSP). An equal amount of TSP solution was applied to five resin groups including commercial protein A resin (GR) as a positive control. The modified 8.5R, 9.5R, 10.5R, and 11.5R showed delayed elution timing compared to the GR control resin. Nano-drop analysis showed that the total amount of purified mAbPSO57 mAbs from 60 g of fresh leaf mass were not significantly different among 8.5R (400 μg), 9.5R (360 μg), 10.5R (380 μg), and GR (350 μg). The 11.5R (25 μg) had the least mAbPSO57. SDS–PAGE analysis showed that the purity of mAbPSO57 was not significantly different among the five groups. Rapid fluorescent focus inhibition tests revealed that virus-neutralizing efficacies of purified mAbPSO57 from all the five different resins including the positive control resin were similar. Taken together, both pH 8.5 and 10.5 coupling conditions with high recovery rate should be optimized for purification of mAbPSO57 from transgenic Arabidopsis plant, which will eventually reduce down-stream cost required for mAb production using the plant system.

scholarly journals Studies on regulation of IGF (insulin-like growth factor)-binding protein (IGFBP) 4 proteolysis by pregnancy-associated plasma protein-A (PAPP-A) in cells treated with phorbol ester

2004 ◽  
Vol 379 (1) ◽  
pp. 57-64 ◽  
Author(s):  
Arun S. SIVANANDAM ◽  
Subburaman MOHAN ◽  
Hirohito KITA ◽  
Sanjay KAPUR ◽  
Shin-Tai CHEN ◽  
...  
Keyword(s):  
Growth Factor ◽  
Proteolytic Activity ◽  
Plasma Protein ◽  
Binding Protein ◽  
Protein A ◽  
Insulin Like Growth Factor ◽  
Factor Binding ◽  
Fold Reduction ◽  
Sds Page ◽  
Eosinophil Major Basic Protein

PAPP-A (pregnancy-associated plasma protein-A) is produced by hSFs (human skin fibroblasts) and hOBs (human osteoblasts) and enhances the mitogenic activity of IGFs (insulin-like growth factors) by degradation of IGFBP-4 (insulin-like growth factor-binding protein 4). PKC (protein kinase C) activation in these cells led to reduction in IGFBP-4 proteolysis. This study was undertaken to determine the mechanism by which activation of PKC suppresses IGFBP-4 proteolysis. Treatment of hSFs/hOBs with TPA (PMA; 100 nM) reduced IGFBP-4 proteolysis without significantly decreasing the PAPP-A level in the CM (conditioned medium). Immunodepletion of the proform of eosinophil major basic protein (proMBP), a known PAPP-A inhibitor, from CM of TPA-treated cells (TPA CM) failed to increase IGFBP-4 proteolytic activity. Transduction of hSFs with proMBP retrovirus increased the concentration of proMBP up to 30 ng/ml and led to a moderate reduction in IGFBP-4 proteolysis. In contrast, TPA treatment blocked IGFBP-4 proteolysis but failed to induce a detectable amount of proMBP in the CM. While proMBP overexpression led to the formation of a covalent proMBP–PAPP-A complex and reduced the migration of PAPP-A on SDS/PAGE, TPA treatment dose- and time-dependently increased the conversion of a ≈470 kDa PAPP-A form (PAPP-A470) to a ≈400 kDa PAPP-A form (PAPP-A400). Since unreduced PAPP-A400 co-migrated with the 400 kDa recombinant PAPP-A homodimer and since PAPP-A monomers from reduced PAPP-A470 and PAPP-A400 co-migrated on SDS/PAGE, conversion of PAPP-A470 to PAPP-A400 is unlikely to be caused by proteolytic cleavage of PAPP-A. Consistent with the data showing that the increase in the ratio of PAPP-A400/PAPP-A470 is correlated with the extent of reduction in IGFBP-4 proteolysis, partially purified PAPP-A400 exhibited a 4-fold reduction in IGFBP-4 proteolytic activity compared with PAPP-A470. These data suggest that a novel mechanism, namely conversion of PAPP-A470 to the less-active PAPP-A400, could account for the TPA-induced suppression of PAPP-A activity.

Phosphorus compounds measured in a rapid and simple leaf test for the assessment of the phosphorus status of subterranean clover

1984 ◽  
Vol 24 (125) ◽  
pp. 213 ◽  
Author(s):  
GCJ Irving ◽  
D Bouma
Keyword(s):  
Leaf Tissue ◽  
Rapid Test ◽  
Subterranean Clover ◽  
Exchange Chromatography ◽  
Phosphorus Compounds ◽  
Fresh Leaf ◽  
Organic Phosphates ◽  
Phosphorus Status ◽  
Colour Development ◽  
Hydrolysis Of

Experiments were done to determine what proportion of the phosphate extracted from fresh leaf tissue by five drops of 10 N H2SO4 represents inorganic tissue phosphate, and to what extent hydrolysis of organic phosphates during and after the extraction, and during the development of the blue phosphomolybdate complex, could contribute to the values obtained. The extraction is the basis of a simple and rapid test for the assessment of the phosphorus status of subterranean clover (Bouma and Dowling 1982). Extraction of leaf tissue of subterranean clover and sunflower with 0.2 M HClO4 at O�C, which was shown to extract inorganic leaf phosphorus without causing significant hydrolysis of organic phosphates, gave values not significantly different from those in H2SO4 extracts. The rate of hydrolysis of endogenous organic phosphates in tissue, extracted and left at room temperature for periods of up to 40 min. after adding H2SO4, did not differ significantly from zero. Errors due to hydrolysis during the 30 min. previously recommended for colour development are reduced to negligible proportions by reducing the time for colour development to 10 min. and by adding citric acid at this point. Anion-exchange chromatography of 10 N H2SO4 and 0.2 M HClO4 extracts confirmed the similarity of their composition and provided estimates of the various phosphate compounds present. The extraction of fresh leaf tissue with 10 N H2SO4 provides a satisfactory estimate of the endogenous inorganic phosphorus content.

scholarly journals Generating and characterizing the anti-human CD45 monoclonal antibody

2020 ◽  
Vol 23 (3) ◽  
pp. 665-672
Author(s):  
Giang Huong Ta ◽  
Huy Quoc Nguyen ◽  
Quan Dang Nguyen
Keyword(s):  
Monoclonal Antibody ◽  
Western Blotting ◽  
Jurkat Cells ◽  
Spleen Cells ◽  
Myeloma Cells ◽  
E Coli ◽  
Common Marker ◽  
Sds Page ◽  
Hybridoma Technology ◽  
Mab Production

Introduction: CD45 is a common marker of leukocytes. Anti-human CD45 monoclonal antibody (MAb) has been used widely in diagnosing and monitoring hematologic diseases. The aim of this study was to generate an anti-human CD45 MAb, which can be used in research and diagnosis. Methods: Recombinant human CD45RO antigen was expressed from E. coli BL21 (DE3), purified and analyzed by SDS-PAGE and Western blotting. The purified CD45RO antigen was used to immunize Balb/c mice. Spleen cells from immunized mouse were collected and fused with P3X63Ag8.653 myeloma cells to form hybridoma. Anti-CD45 antibody-secreting capacity of hybridoma clones was evaluated by ELISA assay. Anti-CD45 MAb from the culture supernatant of the chosen hybridoma clone was purified by affinity chromatography. The MAb was characterized the biochemical characteristics and biological activity. Results: Recombinant human CD45RO antigen was expressed and purified from E.coli BL21 (DE3). Injection of purified CD45RO antigen provoked the immune response in Balb/c mice. Hybridoma clones were generated successfully by the fusion of spleen cells from the selected immunized-mouse and myeloma cells. Among these hybridoma clones, one with the highest yield of MAb production was identified. The isotype of the anti-CD45 MAb created in this work is IgG2b, while its the light chain is kappa (k) type. The affinity of this MAb with CD45RO antigen is high with Kd value at the picomolar level. The anti-CD45 MAb can interact with CD45 naturally expressed on the surface of Jurkat cells in Western blotting and fluorescent immuno-staining assay. Conclusion: We have developed successfully an anti-human CD45 MAb using hybridoma technology, which can recognize CD45 in ELISA, Western blotting, and fluorescent immuno-staining analysis. Although further investigations are necessary, obviously, our anti-human CD45 MAb is potential for research and diagnosis applications.

scholarly journals Improved Phos-tag SDS-PAGE under neutral pH conditions for advanced profiling of protein phosphorylation

2012 ◽  
Vol 56 (Suppl_1) ◽  
pp. s41-s44
Author(s):  
Emiko Kinoshita-Kikuta ◽  
Eiji Kinoshita ◽  
Tohru Koike
Keyword(s):  
Protein Phosphorylation ◽  
Neutral Ph ◽  
Sds Page ◽  
Ph Conditions

EXPRESSION OF PLATELET ALLOANTIGENS ON HUMAN ENDOTHELIAL CELLS AND HEL CELLS

1987 ◽  
Author(s):  
Y Kawai ◽  
R R Montgomery ◽  
K Furihata ◽  
T J Kunicki
Keyword(s):  
Endothelial Cells ◽  
Protein A ◽  
Cell Types ◽  
Membrane Glycoproteins ◽  
Human Endothelial Cells ◽  
Immunoblot Assay ◽  
Sds Page ◽  
Hel Cells ◽  
Erythroleukemia Cell ◽  
Different Cell Types

Analogs of platelet membrane glycoproteins IIb and IIIa (GPIIb-IIIa) have been shown to be synthesized and expressed by human endothelial cells (HEC), a human erythroleukemia cell line (HEL) and various other cells. Previous studies from our laboratory demonstrated that the platelet alloantigen P1A1, is expressed on HEC GPIIIa. Other alloantigen systems, namely, Pen and Bak, are known to be localized on platelet GPIIIa and GPIIb, respectively. Utilizing additional antibodies from patients with PTP specific for Pena, Baka, and Bakb allo-antigens, and isoantibodies (iso-ab) from a patient with Glanzmann's Thrombasthenia (GT), we have studied cultured HEC and HEL cells for expression of epitopes recognized by these antibodies. HEC and HEL cells were meta-bolically labeled with 35S-methionine and lysed in 0.5% TX-100 in the presence of 5mM EDTA. Soluble antigens were immunoprecipitated with these antibodies coupled to Protein A-Sepharose and subjected to SDS-PAGE and fluorography. Anti-Pena and the GT iso-ab reacted with the GPIIb-IIIa complex from both HEC and HEL lysates, but anti-Baka and anti-Bakb failed to immunoprecipitate GPIIb-IIIa analogs from either HEC or HEL. In an immunoblot assay, the GT iso-ab bound to GPIIIa of both HEC and HEL. Anti-Pena failed to react with SDS-denatured proteins. HEL GPIIIa migrates slightly faster than HEC GPIIIa and slightly slower than platelet GPIIIa. These results indicate that the epitopes of platelet GPIIIa recognized by alloantibodies and isoantibodies are shared by GPIIIa analogs of HEC and HEL. GPIIb-associated alloantigens are not expressed by HEC and HEL GPIIb analogs, an observation that is consistent with the decreased structural homology between GPIIb analogs derived from different cell types.

scholarly journals Chemical modification of the lectin of the marine coral Gerardia savaglia by marine quinone avarone

2007 ◽  
Vol 72 (12) ◽  
pp. 1271-1274 ◽  
Author(s):  
Ivana Pajic ◽  
Zoran Vujcic ◽  
Miroslava Vujcic ◽  
Irena Novakovic ◽  
Dusan Sladic ◽  
...  
Keyword(s):  
Chemical Modification ◽  
Isoelectric Focusing ◽  
Marine Sponge ◽  
Protein A ◽  
Hemagglutination Activity ◽  
Sds Page ◽  
Dysidea Avara

The quinone avarone, isolated from the marine sponge Dysidea avara, possesses the ability to chemically modify proteins. In this work, modification of lectin isolated from the coral Gerardia savaglia by avarone was examined. The techniques used for studying the modification were: SDS PAGE, isoelectric focusing and hemagglutination testing. The results of the SDS PAGE indicate dimerization of the protein. A shift of the pI toward lower value occurs upon modification. The change of the hemagglutination activity of the protein confirms that chemical modification of G. savaglia lectin by avarone changes its ability to interact with the membrane of erythrocytes.

scholarly journals Molecular cloning and biochemical characterization of rabbit factor XI

2002 ◽  
Vol 367 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Dipali SINHA ◽  
Mariola MARCINKIEWICZ ◽  
David GAILANI ◽  
Peter N. WALSH
Keyword(s):  
Human Factor ◽  
Biochemical Characterization ◽  
Protein A ◽  
Size Exclusion ◽  
Factor Xi ◽  
Sds Page ◽  
Exclusion Chromatography ◽  
Intracellular Process ◽  
And Function

Human factor XI, a plasma glycoprotein required for normal haemostasis, is a homodimer (160kDa) formed by a single interchain disulphide bond linking the Cys-321 of each Apple 4 domain. Bovine, porcine and murine factor XI are also disulphide-linked homodimers. Rabbit factor XI, however, is an 80kDa polypeptide on non-reducing SDS/PAGE, suggesting that rabbit factor XI exists and functions physiologically either as a monomer, as does prekallikrein, a structural homologue to factor XI, or as a non-covalent homodimer. We have investigated the structure and function of rabbit factor XI to gain insight into the relation between homodimeric structure and factor XI function. Characterization of the cDNA sequence of rabbit factor XI and its amino acid translation revealed that in the rabbit protein a His residue replaces the Cys-321 that forms the interchain disulphide linkage in human factor XI, explaining why rabbit factor XI is a monomer in non-reducing SDS/PAGE. On size-exclusion chromatography, however, purified plasma rabbit factor XI, like the human protein and unlike prekallikrein, eluted as a dimer, demonstrating that rabbit factor XI circulates as a non-covalent dimer. In functional assays rabbit factor XI and human factor XI behaved similarly. Both monomeric and dimeric factor XI were detected in extracts of cells expressing rabbit factor XI. We conclude that the failure of rabbit factor XI to form a covalent homodimer due to the replacement of Cys-321 with His does not impair its functional activity because it exists in plasma as a non-covalent homodimer and homodimerization is an intracellular process.

scholarly journals Activation of Fusion by the SER Virus F Protein: a Low-pH-Dependent Paramyxovirus Entry Process

2003 ◽  
Vol 77 (11) ◽  
pp. 6520-6527 ◽  
Author(s):  
Shaguna Seth ◽  
Annelet Vincent ◽  
R. W. Compans
Keyword(s):  
Elevated Temperatures ◽  
Protein A ◽  
Syncytium Formation ◽  
Simian Virus ◽  
Low Ph ◽  
F Protein ◽  
Simian Virus 5 ◽  
Cytoplasmic Content ◽  
Ph Conditions ◽  
Ph Dependent

ABSTRACT SER virus, a paramyxovirus closely related to simian virus 5, induces no syncytium formation. The SER virus F protein has a long cytoplasmic tail (CT), and truncation or mutations of the CT result in enhanced syncytium formation (S. Seth, A. Vincent, and R. W. Compans, J. Virol. 77:167-178, 2003; S. Tong, M. Li, A. Vincent, R. W. Compans, E. Fritsch, R. Beier, C. Klenk, M. Ohuchi, and H.-D. Klenk, Virology 301:322-333, 2002). We hypothesized that the presence of the long CT serves to stabilize the metastable conformation of the F protein. We observed that the hemifusion, cytoplasmic content mixing, and syncytium formation ability of the wild-type SER virus F coexpressed with the SER virus hemagglutinin-neuraminidase (HN) protein was enhanced, both qualitatively and quantitatively, at elevated temperatures. We also observed enhanced hemifusion, content mixing, and syncytium formation in SER virus F- and HN-expressing cells at reduced pH conditions ranging between 4.8 and 6.2. We have obtained evidence that in contrast to other paramyxoviruses, entry of SER virus into cells occurs by a low-pH-dependent process, indicating that the conversion to the fusion-active state for SER virus F is triggered by exposure to reduced pH.

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