Faecal Methylamine in Normal and Uraemic Subjects

1979 ◽  
Vol 56 (5) ◽  
pp. 509-512 ◽  
Author(s):  
C. W. I. Owens ◽  
W. Padovan
Keyword(s):  
Ion Exchange ◽  
Renal Impairment ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography

1. A ninhydrin-reacting substance seen during ion-exchange chromatography of faecal dialysate obtained in vivo from normal and uraemic subjects has been isolated and identified as methylamine. 2. Faecal dialysate concentrations of methylamine were higher in uraemic subjects and were related to the degree of renal impairment (P < 0·05). 3. Methylamine concentrations in faecal dialysate and centrifugate were not significantly different.

scholarly journals Intein-mediated backbone cyclization of entolimod confers enhanced radioprotective activity in mouse models

2018 ◽  
Author(s):  
Bingyu Ye ◽  
Wenlong Shen ◽  
Minglei Shi ◽  
Yan Zhang ◽  
Cunshuan Xu ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Clinical Investigation ◽  
Affinity Purification ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Size Exclusion ◽  
Radioprotective Activity ◽  
Backbone Cyclization

Background. Entolimod is a Salmonella enterica flagellin derivate. Previous work has demonstrated that entolimod effectively protects mice and non-human primates from ionizing radiation. However, it caused a “flu-like” syndrome after radioprotective and anticancer clinical application, indicating some type of immunogenicity and toxicity. Cyclization is commonly used to improve the in vivo stability and activity of peptides and proteins. Methods. We designed and constructed cyclic entolimod using split Npu DnaE intein with almost 100% cyclization efficiency. We adopted different strategies to purify the linear and circular entolimod due to their different topologies. Results. After Ni-chelating affinity purification, the linear and circular entolimod were purified by size-exclusion and ion-exchange chromatography, respectively. Compared with linear entolimod, the circular entolimod showed significantly increased both the in vitro NF-κB signaling and in vivo radioprotective activity in mice. Discussions/Conclusions. Our data indicates that circular entolimod might be a good candidate for further clinical investigation.

scholarly journals Keratin incorporation into intermediate filament networks is a rapid process.

1991 ◽  
Vol 113 (4) ◽  
pp. 843-855 ◽  
Author(s):  
R K Miller ◽  
K Vikstrom ◽  
R D Goldman
Keyword(s):  
Ion Exchange ◽  
Intermediate Filament ◽  
Immunofluorescence Microscopy ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Type I ◽  
Type Ii ◽  
Filament Networks ◽  
Cytoskeletal Elements

The properties of keratin-containing intermediate filament (IF) networks in vivo were studied following the microinjection of biotinylated keratin. Keratin-IFs were biotinylated, disassembled, and separated into type I and type II proteins by ion exchange chromatography. Recombination of these derivatized type I and type II keratins resulted in the formation of 10-nm diameter IF. The type I keratins were microinjected into epithelial cells and observed by immunofluorescence microscopy. Biotin-rich spots were found throughout the cytoplasm at 15-20 min after injection. Short biotinylated fibrous structures were seen at 30-45 min after injection, most of which colocalized with the endogenous bundles of IF (tono-filaments). By 1 1/2 to 2 h after microinjection, extensive biotinylated keratin IF-like networks were evident. These were highly coincident with the endogenous tonofilaments throughout the cell, including those at desmosomal junctions. These results suggest the existence of a relatively rapid subunit incorporation mechanism using numerous sites along the length of the endogenous tonofilament bundles. These observations support the idea that keratin-IFs are dynamic cytoskeletal elements.

IODOPEPTIDES FROM HUMAN THYROGLOBULIN

1977 ◽  
Vol 85 (4) ◽  
pp. 769-780 ◽  
Author(s):  
Lubomir J. Valenta ◽  
A. Donny Strosberg ◽  
Vera Valenta ◽  
Jean-Claude Jaton
Keyword(s):  
Ion Exchange ◽  
Peptide Mapping ◽  
Thyroid Tissue ◽  
Iodine Content ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Small Peptides ◽  
Thyroid Glands ◽  
High Voltage Electrophoresis

ABSTRACT Human thyroglobulin labelled in vivo by 125I was purified from eight different thyroid glands including normal thyroid tissue, thyrotoxic goitre and euthyroid multinodular goitre. The purified protein was cleaved with cyanogen bromide (CNBr) and the resulting peptides were separated by column chromatography and ion exchange chromatography. Reproducible elution profiles of both protein and iodine were obtained. However, the distribution of iodine depended on the iodine content of the intact thyroglobulin. Small CNBr peptides seemed to be preferentially iodinated, but with a limited capacity. With higher degrees of iodination, larger peptides became richer in iodine. This suggests sequential iodination of the thyroglobulin molecule. The mixture of small peptides was digested by trypsin. Two iodopeptides were identified in this material by peptide mapping and they had identical migration in thyroglobulins of different origin. One of them was purified by ion exchange chromatography and high voltage electrophoresis. Analogous amino acid composition was obtained for the iodopeptide purified from two different thyroglobulins. The data indicates that thyroglobulin iodination occurs in specific portions of the polypeptide chain and probably in a sequential manner.

Effective Transduction of Brain Neurons with Lentiviral Vectors Purified by Ion-Exchange Chromatography

2020 ◽  
Vol 36 (5) ◽  
pp. 89-97
Author(s):  
D.A. Lanshakov
Keyword(s):  
Gene Therapy ◽  
Ion Exchange ◽  
High Titer ◽  
Lentiviral Vectors ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
In Vivo Studies ◽  
Modern Biology ◽  
The Brain

The development of methods for purification viral vectors for gene therapy is one of the most important and urgent problems of modern biology and medicine. Recently, drugs that carry cerebral neurotrophic factors, such as BDNF, have become increasingly popular. However, viral drugs for gene therapy should meet certain requirements, including high titer and applicability for in vivo studies. At the same time, the creation of such vectors requires cost-effective, inexpensive and affordable methods for standard laboratories. This study compares various methods for purification of lentiviral vectors encoding the brain neurotrophic factor, BDNF. The highest titer (1.12 ∙ 109/mL) was obtained via PEG 6 000 precipitation followed by anion-exchange chromatography on two columns of sorbents containing quaternary ammonium groups. Abnormal aggregates of transduced neurons were detected after lentiviruses purified only by PEG precipitation were injected into the brain of a newborn rat. This fact confirms the necessity of the proposed additional chromatographic purification stage. lentivirus, BDNF, ion exchange chromatography, gene therapy, PEG This work was financially supported by budgetary funding project no. 0259-2019-0003-C-01.

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.

scholarly journals Intein-mediated backbone cyclization of entolimod confers enhanced radioprotective activity in mouse models

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5043
Author(s):  
Bingyu Ye ◽  
Wenlong Shen ◽  
Minglei Shi ◽  
Yan Zhang ◽  
Cunshuan Xu ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Clinical Investigation ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Size Exclusion ◽  
Nostoc Punctiforme ◽  
Radioprotective Activity ◽  
Backbone Cyclization

Background Entolimod is a Salmonella enterica flagellin derivate. Previous work has demonstrated that entolimod effectively protects mice and non-human primates from ionizing radiation. However, it caused a “flu-like” syndrome after radioprotective and anticancer clinical application, indicating some type of immunogenicity and toxicity. Cyclization is commonly used to improve the in vivo stability and activity of peptides and proteins. Methods We designed and constructed cyclic entolimod using split Nostoc punctiforme DnaE intein with almost 100% cyclization efficiency. We adopted different strategies to purify the linear and circular entolimod due to their different topologies. Both of linear and circular entolimod were first purified by Ni-chelating affinity chromatography, and then the linear and circular entolimod were purified by size-exclusion and ion-exchange chromatography, respectively. Results The circular entolimod showed significantly increased both the in vitro NF-κB signaling and in vivo radioprotective activity in mice. Conclusion Our data indicates that circular entolimod might be a good candidate for further clinical investigation.

scholarly journals Intein-mediated backbone cyclization of entolimod confers enhanced radioprotective activity in mouse models

2018 ◽  
Author(s):  
Bingyu Ye ◽  
Wenlong Shen ◽  
Minglei Shi ◽  
Yan Zhang ◽  
Cunshuan Xu ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Clinical Investigation ◽  
Affinity Purification ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Size Exclusion ◽  
Radioprotective Activity ◽  
Backbone Cyclization

Background. Entolimod is a Salmonella enterica flagellin derivate. Previous work has demonstrated that entolimod effectively protects mice and non-human primates from ionizing radiation. However, it caused a “flu-like” syndrome after radioprotective and anticancer clinical application, indicating some type of immunogenicity and toxicity. Cyclization is commonly used to improve the in vivo stability and activity of peptides and proteins. Methods. We designed and constructed cyclic entolimod using split Npu DnaE intein with almost 100% cyclization efficiency. We adopted different strategies to purify the linear and circular entolimod due to their different topologies. Results. After Ni-chelating affinity purification, the linear and circular entolimod were purified by size-exclusion and ion-exchange chromatography, respectively. Compared with linear entolimod, the circular entolimod showed significantly increased both the in vitro NF-κB signaling and in vivo radioprotective activity in mice. Discussions/Conclusions. Our data indicates that circular entolimod might be a good candidate for further clinical investigation.

Studies on an Inhibitor of Plasminogen Activation in Human Serum

1973 ◽  
Vol 30 (02) ◽  
pp. 414-424 ◽  
Author(s):  
Ulla Hedner
Keyword(s):  
Ion Exchange ◽  
Human Serum ◽  
Antithrombin Iii ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Specific Adsorption ◽  
Partial Purification ◽  
Plasminogen Activation ◽  
Preparative Electrophoresis

SummaryA procedure is described for partial purification of an inhibitor of the activation of plasminogen by urokinase and streptokinase. The method involves specific adsorption of contammants, ion-exchange chromatography on DEAE-Sephadex, gel filtration on Sephadex G-200 and preparative electrophoresis. The inhibitor fraction contained no antiplasmin, no plasminogen, no α1-antitrypsin, no antithrombin-III and was shown not to be α2 M or inter-α-inhibitor. It contained traces of prothrombin and cerulo-plasmin. An antiserum against the inhibitor fraction capable of neutralising the inhibitor in serum was raised in rabbits.

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