Binding of Pyrene to Cyclodextrin Polymers

1996 ◽  
Vol 50 (4) ◽  
pp. 511-516 ◽  
Author(s):  
T. C. Werner ◽  
Karen Colwell ◽  
Rezik A. Agbaria ◽  
Isiah M. Warner
Keyword(s):  
Polymer Chain ◽  
Gel Filtration ◽  
Water Soluble ◽  
Single Chain ◽  
Dramatic Decrease ◽  
Molecular Weights ◽  
Chromatography Analysis ◽  
Pyrene Fluorescence ◽  
Quencher Concentration ◽  
Rule Out

Polymers containing the three cyclodextrin (CD) molecules, α-CD, β-CD, and γ-CD, linked by epichlorohydrin (α-CDP, β-CDP, and γ-CDP) are highly water-soluble polydisperse mixtures containing CD units joined by repeating glyceryl linkers [-(CH2-CHOH-CH2-) n]. The average n value is 12-15, and gel filtration chromatography analysis indicates that the two major polymer components have molecular weights (MWs) of <2000 (1 CD/polymer chain) and 9-10,000 (4-5 CDs/polymer chain). We have used fluorescence properties to study the binding of pyrene to the three commercially available CDPs and to dialyzed samples of the CDPs, in which the low-MW (<2000, CDPL) and high-MW (9-10,000, CDPH) components have been separated. The pyrene emission I/III ratios for the three polymers are larger and exhibit a smaller range than the I/III ratios for the CD monomers. Moreover, the I/III ratio for the dialyzed polymers, β-CDPL and β-CDPH, are, within error, the same as that for β-CDP. It has been previously shown that additives, such as pentafluoropropanol (PFP), cause a dramatic decrease in the pyrene I/III ratio in the presence of β-CD. No effect on the pyrene I/III ratio is observed when these additives are added in the presence of the CDPs. The pyrene fluorescence decays in the presence of all three native polymers and the dialyzed β-CDPs are quite similar but different from the pyrene fluorescence decays in the presence of the three CD monomers. Moreover, the pyrene lifetimes show much greater dependence on iodide quencher concentration in the presence of CDPs than in the presence of β-CD and γ-CD. These data suggest that pyrene exists in a more exposed and hydrophilic environment when bound to the CDPs than that observed with the CDs. The agreement of the results for pyrene in the presence of β-CDP, β-CDPH, and β-CDPL would seem to rule out significant cooperative binding from two CD units on a single chain, which has previously been suggested. We conclude that pyrene binding to the CDPs may be largely noninclusional, involving considerable participation of the glyceryl linker units.

IDENTIFICATION AND PURIFICATION OF A NEW PROTEIN FROM WATER-SOLUBLE EXTRACTS OF HUMAN ADRENAL GLAND

1979 ◽  
Vol 82 (3) ◽  
pp. 383-NP ◽  
Author(s):  
M. A. AL-AWQATI ◽  
Y. B. GORDON ◽  
T. CHARD
Keyword(s):  
Molecular Weight ◽  
Adrenal Gland ◽  
Gel Filtration ◽  
Water Soluble ◽  
Double Immunodiffusion ◽  
Molecular Weights ◽  
Physicochemical Methods ◽  
Two Peaks ◽  
Sepharose 4B ◽  
New Protein

An homogenate of human foetal adrenal gland was subjected to negative immunoabsorption by column chromatography using anti-whole human serum coupled to Sepharose 4B. Two peaks were eluted and used to immunize rabbits. The antisera produced were absorbed and tested for specificity by double immunodiffusion. Two antigens, which appeared to be specific to the adrenal gland, were identified having molecular weights of 25 000 and 65 000 as determined by gel filtration. The lower molecular weight antigen was isolated by physicochemical methods and found to be a protein. The amino acid composition is reported.

Studies on the purification of Entamoeba histolytica antigens by gel filtration. II. The antigenic properties of the isolated fractions

1970 ◽  
Vol 16 (6) ◽  
pp. 493-498 ◽  
Author(s):  
Z. Ali Khan ◽  
E. Meerovitch
Keyword(s):  
Entamoeba Histolytica ◽  
Gel Filtration ◽  
Water Soluble ◽  
The Other ◽  
Soluble Extract ◽  
Serological Tests ◽  
Molecular Weights ◽  
Antigenic Properties ◽  
Water Soluble Extract

Partially purified fractions of the water-soluble extract of Entamoeba histolytica (DKB strain) obtained by chromatography in Sephadex G-200 (F1, F2, and F4) and G-100 (F3a, F3b, F3c, and F3d) gels were used in various serological tests and their reactivities compared with the whole 1:40 antigen. The main haemagglutinating (HA) and complement-fixing (CF) activities were confined to fractions F1 and F2, which had molecular weights of 650 000 and 229 000, respectively. The 4 to 6 μg/ml of protein contained in these fractions at the optimum dilution gave antibody liters comparable to those for the whole antigen, which had about 77 μg/ml of protein. The other antigen fractions (F4, F3a, F3b, F3c, and F3d) showed very little activity. Fraction F1 had two main precipitin bands (1 and 2), which showed reaction of identity with two of the bands in fraction F2. The other fractions which showed some HA and CF reactivity had trace amounts of these antigens. It is presumed that the antigens specific for precipitin bands 1 and 2 are the main CF and HA antigens.

Interactions of Herbicides with Water-Soluble Soil Organic Matter

Weed Science ◽  
1991 ◽  
Vol 39 (4) ◽  
pp. 667-672 ◽  
Author(s):  
Karrie L. Pennington ◽  
Sidney S. Harper ◽  
William C. Koskinen
Keyword(s):  
High Performance Liquid Chromatography ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
High Performance ◽  
Agricultural Soils ◽  
Gel Filtration ◽  
Water Soluble ◽  
Leaching Potential ◽  
Molecular Weights ◽  
Significant Mechanism

Interactions of water-soluble soil organic matter (WSSOM) with the herbicides bromacil, metribuzin, alachlor, diquat, and paraquat were examined to determine if these interactions can improve predictions of herbicide leaching potential. A high-performance liquid chromatography gel filtration column was used to separate WSSOM extracts from four mineral agricultural soils into fractions with approximate log molecular weights of 4.96 to 6.82. WSSOM fractions were predominantly anionic in nature with some hydrophobic character. The amount of paraquat bound by WSSOM ranged from 1.1 to 2.1 mmol g−1DOC−1 with KDOC (partition coefficient for dissolved organic carbon) values from 0.050 to 0.187 L kg−1. Diquat was bound at 0.9 to 1.5 mmol g−1DOC−1 by the extracts with KDOC values from 0.044 to 0.143 L kg−1. Bromacil, metribuzin, and alachlor did not bind to the extracts tested. WSSOM did not increase paraquat solubility in the presence of soil. Binding of these herbicides to WSSOM in the soils used in this study would not be a significant mechanism for increased mobility and groundwater contamination potential.

scholarly journals Viscoelasticity and Solution Stability of Cyanoethylcellulose with Different Molecular Weights in Aqueous Solution

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3201
Author(s):  
Qian Li ◽  
Yuehu Li ◽  
Zehua Jin ◽  
Yujie Li ◽  
Yifan Chen ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Sol Gel ◽  
Water Soluble ◽  
Effective Control ◽  
Solution Stability ◽  
Cellulose Ethers ◽  
Single Chain ◽  
Molecular Weights ◽  
Chain Complexes ◽  
Sol Gel Transition

Water-soluble cellulose ethers are widely used as stabilizers, thickeners, and viscosity modifiers in many industries. Understanding rheological behavior of the polymers is of great significance to the effective control of their applications. In this work, a series of cyanoethylcellulose (CEC) samples with different molecular weights were prepared with cellulose and acrylonitrile in NaOH/urea aqueous solution under the homogeneous reaction. The rheological properties of water-soluble CECs as a function of concentration and molecular weight were investigated using shear viscosity and dynamic rheological measurements. Viscoelastic behaviors have been successfully described by the Carreau model, the Ostwald-de-Waele equation, and the Cox–Merz rule. The entanglement concentrations were determined to be 0.6, 0.85, and 1.5 wt% for CEC-11, CEC-7, and CEC-3, respectively. All of the solutions exhibited viscous behavior rather than a clear sol-gel transition in all tested concentrations. The heterogeneous nature of CEC in an aqueous solution was determined from the Cox–Merz rule due to the coexistence of single chain complexes and aggregates. In addition, the CEC aqueous solutions showed good thermal and time stability, and the transition with temperature was reversible.

Rapid Isolation of High Molecular Weight Urokinase from Native Human Urine

1982 ◽  
Vol 47 (03) ◽  
pp. 197-202 ◽  
Author(s):  
Kurt Huber ◽  
Johannes Kirchheimer ◽  
Bernd R Binder
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Human Urine ◽  
Gel Filtration ◽  
Chain Structure ◽  
The Other ◽  
Single Chain ◽  
Apparent Homogeneity ◽  
Sequential Adsorption

SummaryUrokinase (UK) could be purified to apparent homogeneity starting from crude urine by sequential adsorption and elution of the enzyme to gelatine-Sepharose and agmatine-Sepharose followed by gel filtration on Sephadex G-150. The purified product exhibited characteristics of the high molecular weight urokinase (HMW-UK) but did contain two distinct entities, one of which exhibited a two chain structure as reported for the HMW-UK while the other one exhibited an apparent single chain structure. The purification described is rapid and simple and results in an enzyme with probably no major alterations. Yields are high enough to obtain purified enzymes for characterization of UK from individual donors.

Solubilization of Itraconazole by Surfactants and Phospholipid-Surfactant Mixtures: Interplay of Amphiphile Structure, pH and Electrostatic Interactions

2020 ◽  
Author(s):  
Zahari Vinarov ◽  
Gabriela Gancheva ◽  
Nikola Burdzhiev ◽  
Slavka S. Tcholakova
Keyword(s):  
Nmr Spectroscopy ◽  
Electrostatic Interactions ◽  
Triazole Ring ◽  
Water Soluble ◽  
Single Chain ◽  
Surfactant Mixtures ◽  
Solubilization Capacity ◽  
Water Soluble Drugs ◽  
Hydrophobic Chain ◽  
Brick Dust

Although surfactants are frequently used in enabling formulations of poorly water-soluble drugs, the link between their structure and drug solubilization capacity is still unclear. We studied the solubilization of the “brick-dust” molecule itraconazole by 16 surfactants and 3 phospholipid:surfactant mixtures. NMR spectroscopy was used to study in more details the drug-surfactant interactions. Very high solubility of itraconazole (up to 3.6 g/L) was measured in anionic surfactant micelles at pH = 3, due to electrostatic attraction between the oppositely charged (at this pH) drug and surfactant molecules. <sup>1</sup>H NMR spectroscopy showed that itraconazole is ionized at two sites (2+ charge) at these conditions: in the phenoxy-linked piperazine nitrogen and in the dioxolane-linked triazole ring. The increase of amphiphile hydrophobic chain length had a markedly different effect, depending on the amphiphile type: the solubilization capacity of single-chain surfactants increased, whereas a decrease was observed for double-chained surfactants (phosphatidylglycerols). The excellent correlation between the chain melting temperatures of phosphatidylglycerols and itraconazole solubilization illustrated the importance of hydrophobic chain mobility. This study provides rules for selection of itraconazole solubilizers among classical single-chain surfactants and phospholipids. The basic physics underpinning the described effects suggests that these rules should be transferrable to other “brick-dust” molecules.

scholarly journals Semi-Crystalline Hydrophobic Polyamidoamines: A New Family of Technological Materials?

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1018
Author(s):  
Massimo Marcioni ◽  
Jenny Alongi ◽  
Elisabetta Ranucci ◽  
Mario Malinconico ◽  
Paola Laurienzo ◽  
...  
Keyword(s):  
Maximum Stress ◽  
Water Resistance ◽  
Prolonged Exposure ◽  
Water Soluble ◽  
Synthesis And Characterization ◽  
Molecular Weights ◽  
New Family ◽  
Methylene Groups ◽  
Methane Flame

The hitherto known polyamidoamines (PAAs) are not suitable as structural materials because they are usually water-soluble or swellable in water. This paper deals with the synthesis and characterization of semi-crystalline hydrophobic PAAs (H-PAAs) by combining different bis-sec-amines with bis-acrylamides obtained from C6–C12 bis-prim-amines. H-PAAs were initially obtained in a solution of benzyl alcohol, a solvent suitable for both monomers and polymers. Their number average molecular weights, M¯n, which were determined with 1H-NMR by evaluating the percentage of their terminal units, varied from 6000 to >10,000. The solubility, thermal properties, ignitability and water resistance of H-PAAs were determined. They were soluble in organic solvents, semi-crystalline and thermally stable. The most promising ones were also prepared using a bulk process, which has never been previously reported for PAA synthesis. In the form of films, these H-PAAs were apparently unaffected by water. The films underwent tensile and wettability tests. They showed similar Young moduli (260–263 MPa), whereas the maximum stress and the stress at break depended on the number of methylene groups of the starting bis-acrylamides. Their wettability was somewhat higher than that of common Nylons. Interestingly, none of the H-PAAs considered, either as films or powders, ignited after prolonged exposure to a methane flame.

scholarly journals Purification and characterization of fat body lipase from the greater wax moth, Galleria mellonella (Lepidoptera: Pyralidae)

2019 ◽  
Vol 81 (1) ◽  
Author(s):  
Rahma R. Z. Mahdy ◽  
Shaimaa A. Mo’men ◽  
Marah M. Abd El-Bar ◽  
Emad M. S. Barakat
Keyword(s):  
Metal Ions ◽  
Kinetic Parameters ◽  
Biochemical Characterization ◽  
Galleria Mellonella ◽  
Fat Body ◽  
Specific Activity ◽  
Larval Instar ◽  
Gel Filtration ◽  
Molecular Weights

Abstract Background Insect lipid mobilization and transport are currently under research, especially lipases and lipophorin because of their roles in the production of energy and lipid transport at a flying activity. The present study has been conducted to purify intracellular fat body lipase for the first time, from the last larval instar of Galleria mellonella. Results Purification methods by combination of ammonium sulfate [(NH4)2SO4] precipitation and gel filtration using Sephadex G-100 demonstrated that the amount of protein and the specific activity of fat body lipase were 0.008633 ± 0.000551 mg/ml and 1.5754 ± 0.1042 μmol/min/mg protein, respectively, with a 98.9 fold purity and recovery of 50.81%. Hence, the sephadex G-100 step was more effective in the purification process. SDS-PAGE and zymogram revealed that fat body lipase showed two monomers with molecular weights of 178.8 and 62.6 kDa. Furthermore, biochemical characterization of fat body lipase was carried out through testing its activities against several factors, such as different temperatures, pH ranges, metal ions, and inhibitors ending by determination of their kinetic parameters with the use of p-nitrophenyl butyrate (PNPB) as a substrate. The highest activities of enzyme were determined at the temperature ranges of 35–37 °C and 37–40 °C and pH ranges of 7–9 and 7–10. The partially purified enzyme showed significant stimulation by Ca2+, K+, and Na+ metal ions indicating that fat body lipase is metalloproteinase. Lipase activity was strongly inhibited by some inhibitors; phenylmethylsulfonyl fluoride (PMSF), ethylene-diaminetetractic acid (EDTA), and ethylene glycoltetraacetic acid (EGTA) providing evidence of the presence of serine residue and activation of enzymes by metal ions. Kinetic parameters were 0.316 Umg− 1 Vmax and 301.95 mM Km. Conclusion Considering the purification of fat body lipase from larvae and the usage of some inhibitors especially ion chelating agents, it is suggested to develop a successful control of Galleria mellonella in near future by using lipase inhibitors.

scholarly journals Influences of Molecular Weights on Physicochemical and Biological Properties of Collagen-Alginate Scaffolds

Marine Drugs ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 85 ◽  
Author(s):  
Truc Cong Ho ◽  
Jin-Seok Park ◽  
Sung-Yeoul Kim ◽  
Hoyeol Lee ◽  
Ju-Sop Lim ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Subcritical Water ◽  
Biological Properties ◽  
Ethanol Solution ◽  
Water Soluble ◽  
Potential Candidate ◽  
High Porosity ◽  
Engineering Applications ◽  
Molecular Weights

For tissue engineering applications, biodegradable scaffolds containing high molecular weights (MW) of collagen and sodium alginate have been developed and characterized. However, the properties of low MW collagen-based scaffolds have not been studied in previous research. This work examined the distinctive properties of low MW collagen-based scaffolds with alginate unmodified and modified by subcritical water. Besides, we developed a facile method to cross-link water-soluble scaffolds using glutaraldehyde in an aqueous ethanol solution. The prepared cross-linked scaffolds showed good structural properties with high porosity (~93%) and high cross-linking degree (50–60%). Compared with collagen (6000 Da)-based scaffolds, collagen (25,000 Da)-based scaffolds exhibited higher stability against collagenase degradation and lower weight loss in phosphate buffer pH 7.4. Collagen (25,000 Da)-based scaffolds with modified alginate tended to improve antioxidant capacity compared with scaffolds containing unmodified alginate. Interestingly, in vitro coagulant activity assay demonstrated that collagen (25,000 Da)-based scaffolds with modified alginate (C25-A63 and C25-A21) significantly reduced the clotting time of human plasma compared with scaffolds consisting of unmodified alginate. Although some further investigations need to be done, collagen (25,000 Da)-based scaffolds with modified alginate should be considered as a potential candidate for tissue engineering applications.

FRACTIONATION OF LIVETIN AND THE MOLECULAR WEIGHTS OF THE α- AND β-COMPONENTS

1957 ◽  
Vol 35 (4) ◽  
pp. 241-250 ◽  
Author(s):  
W. G. Martin ◽  
J. E. Vandegaer ◽  
W. H. Cook
Keyword(s):  
Light Scattering ◽  
Soluble Protein ◽  
Soluble Fraction ◽  
Egg Yolk ◽  
Water Soluble ◽  
Water Soluble Fraction ◽  
Molecular Weights ◽  
Water Soluble Protein ◽  
Hen Egg Yolk ◽  
Hen Egg

Livetin, the major water-soluble protein of hen egg yolk, was found to contain three major components having mobilities of −6.3, −3.8, and −2.1 cm.2 sec.−1 volt−1 at pH 8, µ 0.1, and these have been designated α-, β-, and γ-livetin respectively. The α- and β-livetins were separated and purified electrophoretically after removal of γ-livetin by precipitation from 37% saturated ammonium sulphate or 20% isopropanol. The α-, β-, and mixed livetins resembled pseudoglobulins in solubility but γ-livetin was unstable and this loss of solubility has, so far, prevented its characterization. Molecular weights determined by light scattering, osmotic pressure, and Archibald sedimentation procedure yielded respectively: 8.7, 7.8, and 6.7 × 104 for α-livetin, and 4.8, 5.0, and4.5 × 104 for β-livetin. Under suitable conditions of sedimentation and electrophoresis, egg yolk has been shown to contain three components having the same behavior as the three livetins of the water-soluble fraction.

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