Effect of molecular weight and charge ratio on the stability of the chitosan/DNA complexes

2008 ◽  
Vol 136 ◽  
pp. S178
Author(s):  
Yan Sun ◽  
Lei Fu ◽  
Zhiqiang Xu ◽  
chongfei Xu ◽  
Qian Yang
Keyword(s):  
Molecular Weight ◽  
Charge Ratio ◽  
Dna Complexes ◽  
The Stability

scholarly journals Development and Characterization of Two Types of Surface Displayed Levansucrases for Levan Biosynthesis

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 757
Author(s):  
Huiyi Shang ◽  
Danni Yang ◽  
Dairong Qiao ◽  
Hui Xu ◽  
Yi Cao
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Weight ◽  
Large Scale ◽  
Surface Display ◽  
Yeast Surface Display ◽  
Fusion Partner ◽  
Whole Cell ◽  
Food Industries ◽  
Yeast Surface ◽  
The Stability

Levan has wide applications in chemical, cosmetic, pharmaceutical and food industries. The free levansucrase is usually used in the biosynthesis of levan, but the poor reusability and low stability of free levansucrase have limited its large-scale use. To address this problem, the surface-displayed levansucrase in Saccharomyces cerevisiae were generated and evaluated in this study. The levansucrase from Zymomonas mobilis was displayed on the cell surface of Saccharomyces cerevisiae EBY100 using a various yeast surface display platform. The N-terminal fusion partner is based on a-agglutinin, and the C-terminal one is Flo1p. The yield of levan produced by these two whole-cell biocatalysts reaches 26 g/L and 34 g/L in 24 h, respectively. Meanwhile, the stability of the surface-displayed levansucrases is significantly enhanced. After six reuses, these two biocatalysts retained over 50% and 60% of their initial activities, respectively. Furthermore, the molecular weight and polydispersity test of the products suggested that the whole-cell biocatalyst of levansucrase displayed by Flo1p has more potentials in the production of levan with low molecular weight which is critical in certain applications. In conclusion, our method not only enable the possibility to reuse the enzyme, but also improves the stability of the enzyme.

scholarly journals Effect of Mixing Ratio of Oppositely Charged Block Copolymers on Polyion Complex Micelles for In Vivo Application

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 5
Author(s):  
Noriko Nakamura ◽  
Yuki Mochida ◽  
Kazuko Toh ◽  
Shigeto Fukushima ◽  
Horacio Cabral ◽  
...  
Keyword(s):  
Physicochemical Characteristics ◽  
Charge Ratio ◽  
Structural Variations ◽  
Polyion Complex ◽  
Functional Capabilities ◽  
The Stability ◽  
Biological Performance ◽  
Complex Micelles ◽  
Oppositely Charged

Self-assembled supramolecular structures based on polyion complex (PIC) formation between oppositely charged polymers are attracting much attention for developing drug delivery systems able to endure harsh in vivo environments. As controlling polymer complexation provides an opportunity for engineering the assemblies, an improved understanding of the PIC formation will allow constructing assemblies with enhanced structural and functional capabilities. Here, we focused on the influence of the mixing charge ratio between block aniomers and catiomers on the physicochemical characteristics and in vivo biological performance of the resulting PIC micelles (PIC/m). Our results showed that by changing the mixing charge ratio, the structural state of the core was altered despite the sizes of PIC/m remaining almost the same. These structural variations greatly affected the stability of the PIC/m in the bloodstream after intravenous injection and determined their biodistribution.

scholarly journals The multiple complexes formed by the interaction of platelet factor 4 with heparin

1980 ◽  
Vol 191 (3) ◽  
pp. 769-776 ◽  
Author(s):  
P E Bock ◽  
M Luscombe ◽  
S E Marshall ◽  
D S Pepper ◽  
J J Holbrook
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Chain Length ◽  
Salt Concentration ◽  
Human Platelet ◽  
Platelet Factor 4 ◽  
High Protein ◽  
Platelet Factor ◽  
The Stability ◽  
Very High

The anisotropy of the fluorescence of dansyl (5-dimethylaminonaphthalene-1- sulphonyl) groups covalently attached to human platelet factor 4 was used to detect the macromolecular compounds formed when the factor was mixed with heparin. At low heparin/protein ratios a very-high-molecular-weight compound (1) was formed that dissociated to give a smaller compound (2) when excess heparin was added. 2. A large complex was also detected as a precipitate that formed at high protein concentrations in chloride buffer. It contained 15.7% (w/w) polysaccharide, equivalent to four or five heparin tetrasaccharide units per protein tetramer. In this complex, more than one molecule of protein binds to each heparin molecule of molecular weight greater than about 6 × 10(3).3. The stability of these complexes varied with pH, salt concentration and the chain length of the heparin. The limit complexes found in excess of the larger heparins consisted of only one heparin molecule per protein tetramer, and the failure to observe complexes with four heparin molecules/protein tetramer is discussed.

scholarly journals The composition of peptidochitodextrins from sarcophagid puparial cases

1971 ◽  
Vol 125 (3) ◽  
pp. 703-716 ◽  
Author(s):  
H. Lipke ◽  
T. Geoghegan
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Protein Complex ◽  
Covalent Bonds ◽  
Aromatic Residues ◽  
Similar Molecular Weight ◽  
X Ray ◽  
Molecular Weights ◽  
Physical Interactions ◽  
The Stability

1. N-Bromosuccinimide cleaved proteins and pigments from fly puparia, increasing the chitin:protein ratio from 0.5 to 1.5. The product afforded subfractions (ratio 5:1) of molecular weights of 1200 and 1600 devoid of aromatic residues and N-terminal β-alanine, direct aryl links between polysaccharide chains being discounted. 2. The chitin–protein complex decreased in molecular weight when treated with Pronase, which suggested polypeptide bridges within the native chitin micelle. The limit dextrins generated by chitinase were mixtures of unsubstituted dextrins and peptidylated oligosaccharides, with the former predominating. 3. Peptidochitodextrins of similar molecular weight but markedly different solubility were prepared, which were indistinguishable with respect to amino acid, glucosamine, acetyl, X-ray or infrared characteristics. It is suggested that physical interactions contribute to the stability of the integument in addition to the covalent bonds that form during sclerotization.

scholarly journals Effects Of Environmental Factors On The Dispersion Behavior Of Iron Oxide In Aqueous Solutions With Poly Acrylic Acid

2015 ◽  
Vol 60 (2) ◽  
pp. 1561-1564
Author(s):  
E.-H. Lee ◽  
K.-M. Kim ◽  
W.-Y. Maeng ◽  
D.-H. Hur
Keyword(s):  
Molecular Weight ◽  
Acrylic Acid ◽  
High Molecular Weight ◽  
Low Molecular Weight ◽  
Solution Ph ◽  
Molecular Weights ◽  
Aqueous Suspensions ◽  
Magnetite Particles ◽  
The Stability ◽  
Poly Acrylic Acid

Abstract After preparing aqueous suspensions from magnetite particles with a poly-acrylic acid, we investigated the effects of several experimental parameters. We characterized the stability of the suspensions using visual inspection, sedimentation, adsorption, and thermal stability of the dispersant. The dispersion stability is affected by the solution pH, the concentrations of magnetite particles, the molecular weight, the concentration of the dispersants, and the temperature. The stability of the suspensions increased as the concentration of the dispersant and the temperature increased. In terms of the molecular weights of the dispersant, the suspensions with dispersant of low-molecular weight (1800) were more stable than those of high-molecular weight (250000) at room temperature. However, at high temperature the suspensions with high-molecular weight showed stability. The adsorption efficiency of the dispersant was very low. The dispersant of high-molecular weight showed a higher thermal integrity than that of low-molecular weight. From this work, we obtained the optimum conditions for stable aqueous suspensions of magnetite particles.

scholarly journals Biomolecular Clusters Distribution up to Mega Dalton Region Using MALDI-Quadrupole Ion Trap Mass Spectrometer

2018 ◽  
Vol 19 (9) ◽  
pp. 2789 ◽  
Author(s):  
Yung-Kun Chuang ◽  
Szu-Hsueh Lai ◽  
Jung-Lee Lin ◽  
Chung-Hsuan Chen
Keyword(s):  
Molecular Weight ◽  
Cytochrome C ◽  
Mass Spectrometer ◽  
Ion Trap ◽  
Quadrupole Ion Trap ◽  
Charge Ratio ◽  
Ion Trap Mass Spectrometer ◽  
Quantitative Results ◽  
A Charge ◽  
Large Clusters

We present the first report on complete cluster distributions of cytochrome c (molecular weight of 12.4 kDa) and bovine serum albumin ((BSA), molecular weight of 66.4 kDa) with mass-to-charge ratio (m/z) reaching 350,000 and 1,400,000, respectively, by matrix-assisted laser desorption/ionization (MALDI). Large cluster distributions of the analytes were measured by our homemade frequency-scanned quadrupole ion trap (QIT) mass spectrometer with a charge detector. To our knowledge, we report the highest m/z clusters of these two biomolecules. The quantitative results indicate that large clusters ions of cytochrome c and BSA follow the power law (r2 > 0.99) with cluster size distribution, which provides experimental evidence for the laser ablation studies of MALDI.

scholarly journals Effect of molecular weight of polyvinylpyrrolidone on the skin irritation potential and properties of body wash cosmetics in the coacervate form

2019 ◽  
Vol 91 (9) ◽  
pp. 1521-1532 ◽  
Author(s):  
Tomasz Bujak ◽  
Tomasz Wasilewski ◽  
Zofia Nizioł-Łukaszewska
Keyword(s):  
Molecular Weight ◽  
Skin Irritation ◽  
Innovative Technology ◽  
Foaming Properties ◽  
Cosmetic Products ◽  
Surfactant Mixtures ◽  
Innovative Solutions ◽  
Basic Quality ◽  
Strong Competition ◽  
The Stability

Abstract Body wash cosmetics are among the most common groups of cosmetics used by consumers. Faced with strong competition in the marketplace, cosmetic manufacturers search for innovative solutions both in terms of product composition and form. An example of an innovative technology which can be used in the production of body wash cosmetics is the process of coacervation which yields a concentrated body wash product. Another important aspect which needs to be considered in the formulation of body wash cosmetics is their safety of use. It is crucial to ensure that such cosmetic products do not induce skin irritations. At present, the most widespread method of reducing the skin irritation potential of cosmetic products is the use of surfactant mixtures. The study is an attempt to evaluate the effect of using polyvinylpyrrolidone in the formulations of model body wash cosmetics in the coacervate form on the skin irritation potential and basic quality determinants of body wash products. Polyvinylpyrrolidone was found to contribute to a significant reduction in the irritant effect, and the skin irritation potential decreased in proportion to increasing molecular mass of the polymer. The application of polyvinylpyrrolidone with the different molecular weight also has an impact on improving the foaming properties of model body wash cosmetics and the stability of foam they produce.

scholarly journals An ATP/ADP-Dependent Molecular Switch Regulates the Stability of p53-DNA Complexes

1999 ◽  
Vol 19 (11) ◽  
pp. 7501-7510 ◽  
Author(s):  
Andrei L. Okorokov ◽  
Jo Milner
Keyword(s):  
Dna Damage ◽  
Dna Binding ◽  
Cellular Response ◽  
Atp Hydrolysis ◽  
P53 Protein ◽  
Molecular Switch ◽  
Dna Complexes ◽  
Switch Mechanism ◽  
The Stability ◽  
First Time

ABSTRACT Interaction with DNA is essential for the tumor suppressor functions of p53. We now show, for the first time, that the interaction of p53 with DNA can be stabilized by small molecules, such as ADP and dADP. Our results also indicate an ATP/ADP molecular switch mechanism which determines the off-on states for p53-DNA binding. This ATP/ADP molecular switch requires dimer-dimer interaction of the p53 tetramer. Dissociation of p53-DNA complexes by ATP is independent of ATP hydrolysis. Low-level ATPase activity is nonetheless associated with ATP-p53 interaction and may serve to regenerate ADP-p53, thus recycling the high-affinity DNA binding form of p53. The ATP/ADP regulatory mechanism applies to two distinct types of p53 interaction with DNA, namely, sequence-specific DNA binding (via the core domain of the p53 protein) and binding to sites of DNA damage (via the C-terminal domain). Further studies indicate that ADP not only stabilizes p53-DNA complexes but also renders the complexes susceptible to dissociation by specific p53 binding proteins. We propose a model in which the DNA binding functions of p53 are regulated by an ATP/ADP molecular switch, and we suggest that this mechanism may function during the cellular response to DNA damage.

scholarly journals Binding Affinity, Cellular Uptake, and Subsequent Intracellular Trafficking of the Nano-Gene Vector P123-PEI-R13

2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Yaguang Zhang ◽  
Hongmei Shu ◽  
Jing Hu ◽  
Min Zhang ◽  
Junweng Wu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Cellular Uptake ◽  
Intracellular Trafficking ◽  
Transfection Efficiency ◽  
Cross Linking ◽  
Low Molecular Weight ◽  
Gene Vector ◽  
Dna Complexes ◽  
Dynamic Source

A nano-gene vector PEI-P123-R13 was synthesized by cross-linking low molecular weight PEI with P123 and further coupling bifunctional peptide R13 to the polymer for targeting tumor and increasing cellular uptake. The binding assessment of R13 toαvβ3 positive cells was performed by HRP labeling. The internalization pathways of P123-PEI-R13/DNA complexes were investigated based on the effect of specific endocytic inhibitors on transfection efficiency. The mechanism of intracellular trafficking was investigated based on the effect of endosome-lysosome acidification inhibitors, cytoskeleton, and dynein inhibitors on transfection efficiency. The results indicated that the bifunctional peptide R13 had the ability of binding toαvβ3 positive cellsin vitro. The modification of P123-PEI-R13 with R13 made it display new property of internalization. P123-PEI-R13/DNA complexes were conducted simultaneously via clathrin-mediated endocytosis, caveolin-mediated endocytosis, macropinocytosis, and possible energy-independent route. After internalization, P123-PEI-R13/DNA complexes could escape from the endosome-lysosome system because of its acidification and further took microtubule as the track and dynein as the dynamic source to be transported toward the microtubule (+) end, to wit nucleus, under the action of microfilament, and with the aid of intermediate filament.

Sign in / Sign up

Export Citation Format

Share Document