scholarly journals Determination of the Structural Integrity and Stability of Polysialic Acid during Alkaline and Thermal Treatment

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 165
Author(s):  
Bastian Bartling ◽  
Johanna S. Rehfeld ◽  
Daniel Boßmann ◽  
Ingo de Vries ◽  
Jörg Fohrer ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Large Scale ◽  
Polysialic Acid ◽  
Alkaline Solutions ◽  
Low Molecular Weight ◽  
Outer Cell ◽  
Scale Production ◽  
Thermal Hydrolysis ◽  
E Coli ◽  
Chain Lengths

Polysialic acid (polySia) is a linear homopolymer of varying chain lengths that exists mostly on the outer cell membrane surface of certain bacteria, such as Escherichia coli (E. coli) K1. PolySia, with an average degree of polymerization of 20 (polySia avDP20), possesses material properties that can be used for therapeutic applications to treat inflammatory neurodegenerative diseases. The fermentation of E. coli K1 enables the large-scale production of endogenous long-chain polySia (DP ≈ 130) (LC polySia), from which polySia avDP20 can be manufactured using thermal hydrolysis. To ensure adequate biopharmaceutical quality of the product, the removal of byproducts and contaminants, such as endotoxins, is essential. Recent studies have revealed that the long-term incubation in alkaline sodium hydroxide (NaOH) solutions reduces the endotoxin content down to 3 EU (endotoxin units) per mg, which is in the range of pharmaceutical applications. In this study, we analyzed interferences in the intramolecular structure of polySia caused by harsh NaOH treatment or thermal hydrolysis. Nuclear magnetic resonance (NMR) spectroscopy revealed that neither the incubation in an alkaline solution nor the thermal hydrolysis induced any chemical modification. In addition, HPLC analysis with a preceding 1,2-diamino-4,5-methylenedioxybenzene (DMB) derivatization demonstrated that the alkaline treatment did not induce any hydrolytic effects to reduce the maximum polymer length and that the controlled thermal hydrolysis reduced the maximum chain length effectively, while cost-effective incubation in alkaline solutions had no adverse effects on LC polySia. Therefore, both methods guarantee the production of high-purity, low-molecular-weight polySia without alterations in the structure, which is a prerequisite for the submission of a marketing authorization application as a medicinal product. However, a specific synthesis of low-molecular-weight polySia with defined chain lengths is only possible to a limited extent.

scholarly journals Facile construction of a family of supramolecular gels with good levofloxacin hydrochloride loading capacity

RSC Advances ◽  
2021 ◽  
Vol 11 (21) ◽  
pp. 12641-12648
Author(s):  
Renyuan Chen ◽  
Caidie Xu ◽  
Yihao Lei ◽  
Hongxin Liu ◽  
Yabin Zhu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Alkyl Chain ◽  
Low Molecular Weight ◽  
Loading Capacity ◽  
Supramolecular Gels ◽  
Low Molecular Weight Gelators ◽  
Chain Lengths

A family of low molecular weight gelators with different alkyl chain lengths was constructed, having excellent gelation ability and antibiotic loading capacity. A low molecular weight hydrogelator was obtained by adjusting the length of alkyl chain.

Functional design of glycan-conjugated molecules using a chemoenzymatic approach

2021 ◽  
Author(s):  
Makoto Ogata
Keyword(s):  
Molecular Weight ◽  
Large Scale ◽  
Biological Activities ◽  
Natural Compounds ◽  
Low Molecular Weight ◽  
Functional Design ◽  
Enzymatic Method ◽  
Conjugated Molecules ◽  
Design Synthesis ◽  
And Function

Abstract Carbohydrates play important and diverse roles in the fundamental processes of life. We have established a method for accurately and a large scale synthesis of functional carbohydrates with diverse properties using a unique enzymatic method. Furthermore, various artificial glycan-conjugated molecules have been developed by adding these synthetic carbohydrates to macromolecules and to middle and low molecular weight molecules with different properties. These glycan-conjugated molecules have biological activities comparable to or higher than those of natural compounds, and present unique functions. In this review, several synthetic glycan-conjugated molecules are taken as examples to show design, synthesis and function.

scholarly journals Cloning, expression, and analysis of the group 2 allergen from Dermatophagoides farinae from China

2010 ◽  
Vol 82 (4) ◽  
pp. 941-951 ◽  
Author(s):  
Cui Yu-bao ◽  
Ying Zhou ◽  
Shi Weihong ◽  
Ma Guifang ◽  
Li Yang ◽  
...  
Keyword(s):  
Large Scale ◽  
Alpha Helix ◽  
Random Coil ◽  
Reference Sequence ◽  
Scale Production ◽  
Dermatophagoides Farinae ◽  
E Coli ◽  
Large Scale Production ◽  
Solid Foundation ◽  
Group 2

To obtain the recombinant group 2 allergen product of Dermatophagoides farinae (Der f 2), the Der f 2 gene was synthesized by RT-PCR. The full-length cDNA comprised 441 nucleotides and was 99.3% identical to the reference sequence (GenBank AB195580). The cDNA was bound to vector pET28a to construct plasmid pET28a(+)-Der f 2, which was transformed into E. coli BL21 and induced by IPTG. SDS-PAGE showed a specific band of about 14kDa in the hole cell lysate. s estiated by chroatography, about 3.86 g of the recobinant product as obtained, which conjugated with serum IgE from asthmatic children. The protein had a signal peptide of 17 amino acids. Its secondary structure comprised an alpha helix (19.86%), an extended strand (30.82%), and a random coil (49.32%). The subcellular localization of this allergen was predicted to be at mitochondria. Furthermore, its function was shown to be associated with an MD-2-related lipid-recognition (ML) domain. The results of this study provide a solid foundation for large-scale production of the allergen for clinical diagnosis and treatent of allergic disorders.

scholarly journals Advances in the Metabolic Engineering of Escherichia coli for the Manufacture of Monoterpenes

Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 433 ◽  
Author(s):  
Si-si Xie ◽  
Lingyun Zhu ◽  
Xin-yuan Qiu ◽  
Chu-shu Zhu ◽  
Lv-yun Zhu
Keyword(s):  
Large Scale ◽  
Metabolic Flux ◽  
Process Development ◽  
Pathway Engineering ◽  
Scale Production ◽  
Future Studies ◽  
E Coli ◽  
Large Scale Production ◽  
Rate Limiting ◽  
Dependent Pathway

Monoterpenes are commonly applied as pharmaceuticals and valuable chemicals in various areas. The bioproduction of valuable monoterpenes in prokaryotic microbial hosts, such as E. coli, has progressed considerably thanks to the development of different outstanding approaches. However, the large-scale production of monoterpenes still presents considerable limitations. Thus, process development warrants further investigations. This review discusses the endogenous methylerythritol-4-phosphate-dependent pathway engineering and the exogenous mevalonate-dependent isoprenoid pathway introduction, as well as the accompanied optimization of rate-limiting enzymes, metabolic flux, and product toxicity tolerance. We suggest further studies to focus on the development of systematical, integrational, and synthetic biological strategies in light of the inter disciplines at the cutting edge. Our review provides insights into the current advances of monoterpene bioengineering and serves as a reference for future studies to promote the industrial production of valuable monoterpenes.

Monoclonal antibodies against the capsular K antigen of Escherichia coli (09: K30(A): H12): characterisation and use in analysis of K antigen organisation on the cell surface

1988 ◽  
Vol 34 (10) ◽  
pp. 1159-1165 ◽  
Author(s):  
Mary K. Homonylo ◽  
Sheila J. Wilmot ◽  
Joseph S. Lam ◽  
Leslie A. MacDonald ◽  
Christopher Whitfield
Keyword(s):  
Escherichia Coli ◽  
Molecular Weight ◽  
Monoclonal Antibodies ◽  
Cell Surface ◽  
Molecular Probes ◽  
Low Molecular Weight ◽  
Gel Chromatography ◽  
E Coli ◽  
Capsular Antigen ◽  
K Antigen

Monoclonal antibodies were produced against the capsular antigen of Escherichia coli serotype K(A)30, using a mouse hybridoma system. The antibodies also recognised the chemically identical capsular polysaccharide produced by Klebsiella K20. Chemical modification of the K30 polysaccharide indicated that the glucuronic acid residues found in the E. coli K30 capsular antigen were important in the epitope recognised by these antibodies. Use of the antibodies as molecular probes revealed the presence of two discrete forms of the K30 antigen. One form was comprised of high molecular weight polysaccharide, present as a surface capsular layer. The second form of the antigen was of low molecular weight and was associated with lipopolysaccharide fractions from cell surface polysaccharide extracts. Separation of lipopolysaccharide fractions using gel chromatography in the presence of detergent showed that the low molecular weight K-antigenic fraction comigrated with a lipopolysaccharide lipid A core fraction present in encapsulated E. coli K30 bacteria but absent in acapsular mutants.

cDNA cloning and heterologous expression of a wheat proteinase inhibitor of subtilisin and chymotrypsin (WSCI) that interferes with digestive enzymes of insect pests

2005 ◽  
Vol 386 (4) ◽  
pp. 383-389 ◽  
Author(s):  
Simone Di Gennaro ◽  
Anna G. Ficca ◽  
Daniela Panichi ◽  
Elia Poerio
Keyword(s):  
Proteinase Inhibitor ◽  
Large Scale ◽  
Insect Pests ◽  
Expression System ◽  
Physiological Role ◽  
Scale Production ◽  
Insect Larvae ◽  
E Coli ◽  
Large Scale Production ◽  
Degenerate Oligonucleotide

Abstract A cDNA encoding the proteinase inhibitor WSCI (wheat subtilisin/chymotrypsin inhibitor) was isolated by RT-PCR. Degenerate oligonucleotide primers were designed based on the amino acid sequence of WSCI and on the nucleotide sequence of the two homologous inhibitors (CI-2A and CI-2B) isolated from barley. For large-scale production, wsci cDNA was cloned into the E. coli vector pGEX-2T. The fusion protein GST-WSCI was efficiently produced in the bacterial expression system and, as the native inhibitor, was capable of inhibiting bacterial subtilisin, mammalian chymotrypsins and chymotrypsin-like activities present in crude extracts of a number of insect larvae (Helicoverpa armigera, Plodia interpunctella and Tenebrio molitor). The recombinant protein produced was also able to interfere with chymotrypsin-like activity isolated from immature wheat caryopses. These findings support a physiological role for this inhibitor during grain maturation.

scholarly journals Anti-inflammatory activity of low molecular weight polysialic acid on human macrophages

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Anahita Shahraz ◽  
Jens Kopatz ◽  
Rene Mathy ◽  
Joachim Kappler ◽  
Dominic Winter ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Polysialic Acid ◽  
Inflammatory Activity ◽  
Low Molecular Weight ◽  
Human Macrophages ◽  
Anti Inflammatory

scholarly journals Media Optimization for Production of Recombinant Carrier Protein (CRM197) in Escherichia coli

2021 ◽  
Vol 13 (1) ◽  
pp. 283-297
Author(s):  
S. Shukla ◽  
D. Mishra
Keyword(s):  
Escherichia Coli ◽  
Large Scale ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Luria Bertani ◽  
Lag Phase ◽  
Carrier Protein ◽  
Scale Production ◽  
E Coli ◽  
Defined Media

Since the advent of vaccines, the mankind has benefited from the same and has been able to curb the mortality rate around the globe. Amongst different types of available vaccines, polysaccharide based vaccines are very widely used against various infectious diseases. The polysaccharide vaccines need to be conjugated with a carrier protein to make the vaccine more immunogenic. Recombinant Escherichia coli cells are the organism of choice for large scale production of a carrier protein because of its widely studied scientific aspects. In the present study, for proof of concept, the recombinant E. coli cells were cultured in Luria-Bertani media to check the expression of rCRM197. At 80L scale, it was observed that when recombinant E. coli cells were grown in a chemically defined media, it resulted in inconsistent growth and a long lag phase. When the defined media was supplemented with yeast extract, the lag phase of the culture was substantially reduced and the maximum growth of the culture was achieved. Protein expression was checked using SDS PAGE (Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis) and Western blot technique. The optimized media resulted in a robust fermentation process to achieve high cell density and maximum biomass for the production of recombinant protein.

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