scholarly journals Structure of the omalizumab Fab

2015 ◽  
Vol 71 (4) ◽  
pp. 419-426 ◽  
Author(s):  
Rasmus K. Jensen ◽  
Melanie Plum ◽  
Luna Tjerrild ◽  
Thilo Jakob ◽  
Edzard Spillner ◽  
...  
Keyword(s):  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Size Exclusion ◽  
Structural Basis ◽  
Hek 293 ◽  
Functional Studies ◽  
293 Cells ◽  
Exclusion Chromatography ◽  
Ige Mediated ◽  
High Affinity Ige Receptor

Omalizumab is a humanized anti-IgE antibody that inhibits the binding of IgE to its receptors on mast cells and basophils, thus blocking the IgE-mediated release of inflammatory mediators from these cells. Omalizumab binds to the Fc domains of IgE in proximity to the binding site of the high-affinity IgE receptor Fc∊RI, but the epitope and the mechanisms and conformations governing the recognition remain unknown. In order to elucidate the molecular mechanism of its anti-IgE activity, the aim was to analyse the interaction of omalizumab with human IgE. Therefore, IgE Fc C∊2–4 was recombinantly produced in mammalian HEK-293 cells. Functionality of the IgE Fc was proven by ELISA and mediator-release assays. Omalizumab IgG was cleaved with papain and the resulting Fab was purified by ion-exchange chromatography. The complex of IgE Fc with omalizumab was prepared by size-exclusion chromatography. However, crystals containing the complex were not obtained, suggesting that the process of crystallization favoured the dissociation of the two proteins. Instead, two structures of the omalizumab Fab with maximum resolutions of 1.9 and 3.0 Å were obtained. The structures reveal the arrangement of the CDRs and the position of omalizumab residues known from prior functional studies to be involved in IgE binding. Thus, the structure of omalizumab provides the structural basis for understanding the function of omalizumab, allows optimization of the procedure for complex crystallization and poses questions about the conformational requirements for anti-IgE activity.

scholarly journals Oxalic acid degradation by a novel fungal oxalate oxidase from Abortiporus biennis

2016 ◽  
Vol 63 (3) ◽  
Author(s):  
Marcin Grąz ◽  
Kamila Rachwał ◽  
Radosław Zan ◽  
Anna Jarosz-Wilkołazka
Keyword(s):  
Oxalic Acid ◽  
Ph Value ◽  
Enzyme Reaction ◽  
Oxalate Oxidase ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Size Exclusion ◽  
Optimum Temperature ◽  
Intracellular Enzyme ◽  
Exclusion Chromatography

Oxalate oxidase was identified in mycelial extracts of a basidiomycete Abortiporus biennis strain. Intracellular enzyme activity was detected only after prior lowering of the pH value of the fungal cultures by using oxalic or hydrochloric acids. This enzyme was purified using size exclusion chromatography (Sephadex G-25) and ion-exchange chromatography (DEAE-Sepharose). This enzyme exhibited optimum activity at pH 2 when incubated at 40°C, and the optimum temperature was established at 60°C. Among the tested organic acids, this enzyme exhibited specificity only towards oxalic acid. Molecular mass was calculated as 58 kDa. The values of Km for oxalate and Vmax for the enzyme reaction were 0.015 M and 30 mmol min-1, respectively.

Large-scale preparation of α-D-(14)-oligogalacturonic acids from pectic acid

2002 ◽  
Vol 80 (8) ◽  
pp. 900-903 ◽  
Author(s):  
Hong-Ni Fan ◽  
Mei-Zheng Liu ◽  
Yuan C Lee
Keyword(s):  
Galacturonic Acid ◽  
Large Scale ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Size Exclusion ◽  
Inexpensive Method ◽  
Pectic Acid ◽  
Large Scale Preparation ◽  
Exclusion Chromatography ◽  
Scale Preparation

An efficient and inexpensive method for large-scale preparation of α-D-(1[Formula: see text]4)-oligogalacturonic acids (oligo-GalA), up to DP 5, from pectic acid is described. Pectic acid was digested with a commercially available pectinase to yield a mixture of oligo-GalA, which was effectively separated by a combination of low-pressure – size-exclusion chromatography based on ion-exchange chromatography to obtain pure oligo-GalA of DP 2-5. Key words: pectic acid, galacturonic acid, galabiose, galatriose, pectinase.

scholarly journals Purification and Characterization of Transglutaminase from Streptomyces sp. TTA 02 SDS 14

2016 ◽  
Vol 11 (3) ◽  
Author(s):  
Lia Siti Nur'amaliyah ◽  
Dewi Seswita Zilda ◽  
Nisa Rachmania Mubarik
Keyword(s):  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Size Exclusion ◽  
Phenacyl Bromide ◽  
Optimum Temperature ◽  
Purification And Characterization ◽  
Streptomyces Sp ◽  
Exclusion Chromatography ◽  
Sulfonyl Fluoride

Streptomyces sp. TTA 02 SDS 14 is a transglutaminase producing bacteria which previously had been  screened along with more than one hundred isolates. This research aimed to purify and characterize transglutaminase from this strain. Transglutaminase was purified from crude enzyme by ultrafiltration, Q-Sepharose ion exchange chromatography and Sepacryl S200 size exclusion chromatography sequentially, obtaining yield and purification fold of  1.36%  and 27 folds, respectively. The molecular weight of the purified transglutaminase was 72 kDa detected by zymogram gel electrophoresis. The optimum temperature and pH were 50°C and 6. The transglutaminase was stable at 45°C and could be activated in the presence of 5 mM and 10 mM of Na+, K+, Li+,Ca2+, Mg2+, BPB (4-bromo-phenacyl bromide), and IAA (iodo acetamide acid), but the activity was inhibited by  the presence of Cu+, Zn2+, and PMSF (phenyl methyl sulfonyl fluoride).

scholarly journals Structure of a Rhamnogalacturonan Fragment from Apple Pectin: Implications for Pectin Architecture

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Xiangmei Wu ◽  
Andrew Mort
Keyword(s):  
Galacturonic Acid ◽  
2D Nmr ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Size Exclusion ◽  
Direct Connection ◽  
Apple Pectin ◽  
Nmr Spectrometry ◽  
Exclusion Chromatography ◽  
Rhamnogalacturonan Hydrolase

A commercial apple pectin was sequentially digested with the cloned enzymes endopolygalacturonase, galactanase, arabinofuranosidase, xylogalacturonase, and rhamnogalacturonan hydrolase. The rhamnogalacturonan hydrolase-generated oligosaccharides were separated by ultrafiltration, anion exchange, and size-exclusion chromatography. Fractions from the ion exchange chromatography were pooled, lyophilized, and screened by MALDI-TOF MS. An oligosaccharide (RGP14P3) was identified and its structure, α-D-GalpA-(1→2)-α-L-Rhap-(1→4)-α-D-GalpA-(1→2)-α-L-Rhap-(1→4)-α-D-GalpA, determined by 1D and 2D NMR spectrometry. This oligosaccharide probably represents a direct connection between homogalacturonan and rhamnogalacturonan in pectin. Alternatively, it could indicate that the nonreducing end of rhamnogalacturonan starts with a galacturonic acid residue.

scholarly journals Peroxidase from infected fruit of Solanum sp. grown in Nsukka

2019 ◽  
Vol 54 (2) ◽  
pp. 131-138
Author(s):  
Omeje KO ◽  
Eze SOO ◽  
FC Chilaka
Keyword(s):  
Molecular Weight ◽  
Quality Control ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Size Exclusion ◽  
Optimum Temperature ◽  
Ammonium Sulfate Precipitation ◽  
Optimum Ph ◽  
Exclusion Chromatography ◽  
The Ideal

In this study, we characterized the activity of peroxidase a quality control enzyme from the infected fruit of Solanum sp. Peroxidase was purified to homogeneity by ammonium sulfate precipitation, dialysis, ion exchange chromatography and size exclusion chromatography. The molecular weight of the native enzyme was 63000 da. The enzyme was shown to have two iso-enzymes with distinct optimum pH of 4.5 and 7.0 and optimum temperature of 40 and 70⁰C. The purified enzyme had broad substrate specificity with o-dianisidine being the ideal substrate. Na+, Ca2+, Mg2+, Mn2+, Cu2+, Al3+ were shown to be activators of the enzyme, while the peroxidase activity was severely inhibited by Co2+. Bangladesh J. Sci. Ind. Res.54(2), 131-138, 2019

scholarly journals Expression of Monomeric Insulin Precursor in Pichia pastoris and Its Conversion into Monomeric B27 Lys Destripeptide Insulin by Tryptic Hydrolysis

2005 ◽  
Vol 37 (4) ◽  
pp. 234-240 ◽  
Author(s):  
Jin-Guo Ding ◽  
Jian Fei ◽  
Da-Fu Cui ◽  
You-Shang Zhang
Keyword(s):  
Pichia Pastoris ◽  
Ion Exchange ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Size Exclusion ◽  
Spectrometric Analysis ◽  
Exclusion Chromatography ◽  
Native Gel ◽  
Tryptic Hydrolysis

Abstract Monomeric B27 Lys destripeptide insulin (B27 Lys DTrI) was designed and produced from its precursor expressed in Pichia pastoris through tryptic hydrolysis instead of the less efficient tryptic transpeptidation. The monomeric B27 Lys DTrI precursor (MIP) was purified from a cultured medium of P. pastoris by a combination of hydrophobic, size-exclusion, and ion-exchange chromatography. The purified MIP was converted, by tryptic hydrolysis, to B27 Lys DTrI, which was then purified by ion-exchange chromatography to homogeneity as assessed by native gel electrophoresis, HPLC, amino acid composition, and electrospray mass-spectrometric analysis. B27 Lys DTrI exhibited superior monomeric properties in size-exclusion chromatography. The yield of MIP was 200 mg per liter of culture, and the overall yield of purified B27 Lys DTrI from the crude MIP was 70%. The in vivo biological activity of B27 Lys DTrI as determined by the mouse convulsion assay was 21 U/mg, identical to that obtained by semisynthesis.

Frequent Occurrence of HIV-Inhibitory Sulphated Polysaccharides in Marine Invertebrates

1993 ◽  
Vol 4 (3) ◽  
pp. 167-172 ◽  
Author(s):  
J. A. Beutler ◽  
T. C. McKee ◽  
R. W. Fuller ◽  
M. Tischler ◽  
J. H. Cardellina ◽  
...  
Keyword(s):  
Marine Invertebrates ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Size Exclusion ◽  
Aqueous Extracts ◽  
Sulphated Polysaccharides ◽  
Anionic Polysaccharides ◽  
Gel Permeation ◽  
Anti Hiv ◽  
C Nmr

Aqueous extracts of many marine invertebrates have exhibited some activity in the National Cancer Institute's primary screen for anti-HIV cytopathicity. Using a variety of techniques, including gel permeation, size exclusion and ion exchange chromatography, toluidine blue metachromicity, 13C-NMR spectroscopy and combustion analyses, we have determined that this activity is largely due to sulphated polysaccharides. Because of the wide occurrence of this class of compounds in these organisms we sought a method for the rapid dereplication of sulphated polysaccharides. It was critical that the method selected for dereplication allow differentiation of anionic polysaccharides from other AIDS-antiviral chemotypes. After evaluating a variety of methods, we found that the most efficient strategy appeared to be precipitation of the polysaccharide fraction from aqueous ethanolic solutions of the crude aqueous extracts.

Molecular and biochemical characteristics of inulosucrase InuBK from Alkalihalobacillus krulwichiae JCM 11 691

2021 ◽  
Author(s):  
Ken-ji Yokoi ◽  
Sosyu Tsutsui ◽  
Gen-ya Arakawa ◽  
Masakazu Takaba ◽  
Koichi Fujii ◽  
...  
Keyword(s):  
High Performance ◽  
Culture Medium ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Size Exclusion ◽  
Resonance Spectroscopy ◽  
Gene Encoding ◽  
Reading Frame ◽  
Exclusion Chromatography ◽  
Chain Lengths

Abstract Information about the inulosucrase of non-lactic acid bacteria is scarce. We found a gene encoding inulosucrase (inuBK) in the genome of the gram-positive bacterium Alkalihalobacillus krulwichiae JCM 11691. The inuBK open reading frame encoded a protein comprising 456 amino acids. We expressed His-tagged InuBK in culture medium using a Brevibacillus system. The optimal pH and temperature of purified InuBK were 7.0–9.0 and 50 °C–55 °C, respectively. The findings of high-performance anion-exchange chromatography, nuclear magnetic resonance spectroscopy, and high-performance size-exclusion chromatography with multi-angle laser light scattering showed that the polysaccharide produced by InuBK was an inulin with a molecular weight of 3,806, a polydispersity index (PI) of 1.047, and fructosyl chain lengths with 3–27 degrees of polymerization. The size of InuBK was smaller than commercial inulins, and the PI of the inulin that it produced was lower.

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