Physico-chemical properties of 2,6-TNS binding sites in squid giant axons: Involvement of water molecules in the excitation process

1974 ◽  
Vol 18 (1) ◽  
pp. 263-276 ◽  
Author(s):  
E. Carbone ◽  
K. Sisco ◽  
A. Warashina
Keyword(s):  
Binding Sites ◽  
Chemical Properties ◽  
Water Molecules ◽  
Excitation Process ◽  
Giant Axons ◽  
Physico Chemical

scholarly journals Tryptic phosphopeptides from whole casein. II. Physicochemical properties related to the solubilization of calcium

1989 ◽  
Vol 56 (3) ◽  
pp. 335-341 ◽  
Author(s):  
Rafael Berrocal ◽  
Serge Chanton ◽  
Marcel A. Juillerat ◽  
Blaise Favillare ◽  
Jean-Claude Scherz ◽  
...  
Keyword(s):  
Binding Sites ◽  
Calcium Phosphates ◽  
Chemical Properties ◽  
Sodium Caseinate ◽  
Ph Values ◽  
Physico Chemical ◽  
Casein Phosphopeptides ◽  
Hydrolysis Of ◽  
Phosphate Solutions ◽  
Tryptic Hydrolysis

SummaryCasein phosphopeptides (GPP) were produced by tryptic hydrolysis of sodium caseinate and further purified by precipitation and chromatography on QAE-Sephadex A-25. Their physico-chemical properties were compared with the properties of an enzymically dephosphorylated equivalent preparation (DPP). Binding of Ca2+ to the peptides was measured using a Ca selective electrode and was found to increase with pH and to show 1/1 stoicheiometry Ca/Porg in CPP at pH 6·5 a.nd 7·6. Klotz plots indicated equivalent binding sites at these two pH values, but some heterogeneity was seen at pH 3·5. In contrast, DPP did not bind significant amounts of Ca2+.CPP effectively inhibited the formation of insoluble calcium phosphates at different Ca/P ratios. The effective CPP concentration was 10 mg/1 and complete stability of calcium phosphate solutions was obtained at about 100 mg/1. This stabilizing effect was dependent on the presence of organic P.

Common pharmacological and physico-chemical properties of 5-HT3 binding sites in the rat cerebral cortex and NG 108-15 clonal cells

1990 ◽  
Vol 40 (7) ◽  
pp. 1541-1550 ◽  
Author(s):  
F.J. Bolan̄os ◽  
L.E. Schechter ◽  
M.C. Miquel ◽  
M.B. Emerit ◽  
J.F. Rumigny ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Binding Sites ◽  
Chemical Properties ◽  
Rat Cerebral Cortex ◽  
Physico Chemical

Nanostructures of Water Molecules in Iteratively Filtered Water

2011 ◽  
Vol 495 ◽  
pp. 37-40 ◽  
Author(s):  
Vittorio Elia ◽  
Elena Napoli
Keyword(s):  
Electrical Conductivity ◽  
Chemical Properties ◽  
Dissipative Structures ◽  
Living Systems ◽  
Water Molecules ◽  
Distilled Water ◽  
Main Ingredient ◽  
Structure Of Water ◽  
Physico Chemical

This work presents some experimental results on the variation of the physico-chemical properties of pure, twice distilled water, when subject to a procedure of iterative filtrations through Pyrex glass filters (Büchner funnels). The study involves the determination of electrical conductivity. After the filtrations, electrical conductivity increases three times. Part of those increases, about 10-30%, is to be attributed to impurities released by the glass filters. The hypothesis is that the remaining 70-90% of the increases comes from variations in the super-molecular structure of water. The iterative filtration procedure involves a flux of energy and material in an open system. The energy flux is partially dissipated as heat permitting the formation of “dissipative structures”. Water, the main ingredient of living systems, exhibits an extraordinary auto-organization potentiality triggered by several kinds of perturbations, including mechanical ones.

scholarly journals Synthesis and magnetic studies of copper(II)-lanthanide(III) 5-bromosalicylideneglycylglycine

2018 ◽  
Vol 34 (1) ◽  
pp. 25
Author(s):  
Beata Cristóvão ◽  
Wieslawa Ferenc ◽  
J. Sarzyński ◽  
Halina Głuchowska
Keyword(s):  
Magnetic Measurements ◽  
Thermal Analyses ◽  
Chemical Properties ◽  
Water Molecules ◽  
Magnetic Studies ◽  
Magnetic Susceptibility Data ◽  
Susceptibility Data ◽  
Physico Chemical ◽  
Heteronuclear Complexes ◽  
Two Stages

The physico-chemical properties of the new 3d-4f heteronuclear complexes with general formula LnCu3(C11H8N2O4Br)3·13H2O (where Ln = Pr, Eu, Gd, Tb, Er, Yb and H3(C11H8N2O4Br) – 5-bromosalicylideneglycylglycine) were studied. The compounds were characterized by elemental, spectral and thermal analyses and magnetic measurements. The formation of Schiff base is evidenced by a strong band at ca. 1646–1650 cm–1 attributable to C=N stretching mode. The presence of water molecules is confirmed by broad absorptions with maximum at 3360 – 3368 cm-1. The Cu(II)–Ln(III) complexes are stable up to ca. 318 K. During dehydration process the water molecules are lost probably in two stages. The magnetic susceptibility data for these complexes change with temperature according to the Curie-Weiss law.

CONTROL OF PHYSICO-CHEMICAL PROPERTIES OF A LIPID NANOCONTAINER FOR DELIVERY OF DRUGS WITH LOW BIOAVAILABILITY

2020 ◽  
pp. 153-154
Author(s):  
I. Yakimov ◽  
I. Le-Deygen ◽  
A. Skuredina ◽  
E. Kudryashova
Keyword(s):  
Targeted Delivery ◽  
Binding Sites ◽  
Chemical Properties ◽  
Anionic Phospholipid ◽  
Molecular Weights ◽  
Physico Chemical ◽  
Drug Incorporation ◽  
Mannose Derivatives ◽  
Derivatives Of ◽  
Selection Of

We have used two ways to control the physicochemical properties of liposomal nanocontainers for the delivery of fluoroquinolones: variation of the lipid composition of liposomes and selection of a functionalizing polymer based on chitosan mannose derivatives. The presence of anionic phospholipid cardiolipin in the liposome composition increases the loading efficiency by 5-20%. The mechanism of drug incorporation into membranes was studied, and the main binding sites were determined. The functionalization of the liposomal surface was carried out by chitosan mannose derivatives of various molecular weights, potentially providing targeted delivery to alveolar macrophages.

scholarly journals Impact of biopolymer matrices on relaxometric properties of contrast agents

2016 ◽  
Vol 6 (6) ◽  
pp. 20160061 ◽  
Author(s):  
Alfonso Maria Ponsiglione ◽  
Maria Russo ◽  
Paolo Antonio Netti ◽  
Enza Torino
Keyword(s):  
Contrast Agents ◽  
Metal Chelate ◽  
Chemical Properties ◽  
Metal Chelates ◽  
Titration Calorimetry ◽  
Water Molecules ◽  
Polymer Conformation ◽  
Self Diffusion ◽  
Physico Chemical ◽  
The Impact

Properties of water molecules at the interface between contrast agents (CAs) for magnetic resonance imaging and macromolecules could have a valuable impact on the effectiveness of metal chelates. Recent studies, indeed, demonstrated that polymer architectures could influence CAs' relaxivity by modifying the correlation times of the metal chelate. However, an understanding of the physico-chemical properties of polymer/CA systems is necessary to improve the efficiency of clinically used CAs, still exhibiting low relaxivity. In this context, we investigate the impact of hyaluronic acid (HA) hydrogels on the relaxometric properties of Gd-DTPA, a clinically used CA, to understand better the determining role of the water, which is crucial for both the relaxation enhancement and the polymer conformation. To this aim, water self-diffusion coefficients, thermodynamic interactions and relaxometric properties of HA/Gd-DTPA solutions are studied through time-domain NMR relaxometry and isothermal titration calorimetry. We observed that the presence of Gd-DTPA could alter the polymer conformation and the behaviour of water molecules at the HA/Gd-DTPA interface, thus modulating the relaxivity of the system. In conclusion, the tunability of hydrogel structures could be exploited to improve magnetic properties of metal chelates, inspiring the development of new CAs as well as metallopolymer complexes with applications as sensors and memory devices.

scholarly journals Magnetic, spectrochemical and thermal properties of the 2-chloro-5-nitrobenzoates of Co(II), Ni(II) and Cu(II)

2006 ◽  
Vol 71 (8-9) ◽  
pp. 929-937 ◽  
Author(s):  
Wiesława Ferenc ◽  
Agnieszka Walków-Dziewulska ◽  
Beata Cristóvão ◽  
Jan Sarzyñski
Keyword(s):  
Thermal Decomposition ◽  
Thermal Properties ◽  
Metal Ion ◽  
Chemical Properties ◽  
Water Molecules ◽  
Dehydration Process ◽  
Crystallization Water ◽  
Physico Chemical ◽  
One Step ◽  
Hydrated Complexes

Some physico-chemical properties of the 2-chloro-5-nitrobenzoates of Co(II) Ni(II) and Cu(II) were studied. The complexes were obtained as hydrates with a metal ion to ligand ratio of 1:2. All the complexes were polycrystalline compounds. Their colors depended on the nature of the central ion: pink for the Co(II) complex, green for the Ni(II) and blue for the Cu(II) compounds. Their thermal decomposition was studied in the range of 293-523 K because it was found that the 2-chloro-5-nitrobenzoates decomposed explosively on heating in air above 523 K. The hydrated complexes lost crystallization water molecules in one step. From the results, it appeared that no transformation of the nitro group to nitrite occurred during the dehydration process. Their solubilities in water at 293 K were of the order of 10-2 mol dm-3 for the Ni(II) and Co(II) complexes and 10-4 mol dm-3 for that of Cu(II). The magnetic moment values of Co2+, Ni2+ and Cu2+ in the 2-chloro-5-nitrobenzoates, experimentally determined in the range, of 76-303 K ranged from 3.48 to 3.82 ?B for Co(II), from 2.69 to 3.08 ?B for the Ni(II) and from 1.87 to 2.00 ?B for the Cu(II) complex. The 2-chloro-5-nitrobenzoates of Co(II), Ni(II) and Cu(II) followed the Curie-Weiss law.

Decoration of specific sites on freeze-fractured membranes

1978 ◽  
Vol 36 (2) ◽  
pp. 140-141
Author(s):  
H. Gross ◽  
H. Moor
Keyword(s):  
Pure Water ◽  
Freeze Fracture ◽  
Chemical Properties ◽  
Surface Forces ◽  
Sulfate Pentahydrate ◽  
Copper Sulfate Pentahydrate ◽  
Physico Chemical ◽  
Water Of Hydration ◽  
Small Container ◽  
Binding Forces

Fracturing under ultrahigh vacuum (UHV, p ≤ 10-9 Torr) produces membrane fracture faces devoid of contamination. Such clean surfaces are a prerequisite foe studies of interactions between condensing molecules is possible and surface forces are unequally distributed, the condensate will accumulate at places with high binding forces; crystallites will arise which may be useful a probes for surface sites with specific physico-chemical properties. Specific “decoration” with crystallites can be achieved nby exposing membrane fracture faces to water vopour. A device was developed which enables the production of pure water vapour and the controlled variation of its partial pressure in an UHV freeze-fracture apparatus (Fig.1a). Under vaccum (≤ 10-3 Torr), small container filled with copper-sulfate-pentahydrate is heated with a heating coil, with the temperature controlled by means of a thermocouple. The water of hydration thereby released enters a storage vessel.

Physico-Chemical Properties of Recombinant Desulphatohirudin

1990 ◽  
Vol 63 (03) ◽  
pp. 499-504 ◽  
Author(s):  
A Electricwala ◽  
L Irons ◽  
R Wait ◽  
R J G Carr ◽  
R J Ling ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Gel Filtration ◽  
Chemical Properties ◽  
Alpha Helix ◽  
Apparent Molecular Weight ◽  
Correlation Spectroscopy ◽  
Nmr Studies ◽  
Recombinant Hirudin ◽  
Physico Chemical ◽  
Recombinant Molecule

SummaryPhysico-chemical properties of recombinant desulphatohirudin expressed in yeast (CIBA GEIGY code No. CGP 39393) were reinvestigated. As previously reported for natural hirudin, the recombinant molecule exhibited abnormal behaviour by gel filtration with an apparent molecular weight greater than that based on the primary structure. However, molecular weight estimation by SDS gel electrophoresis, FAB-mass spectrometry and Photon Correlation Spectroscopy were in agreement with the theoretical molecular weight, with little suggestion of dimer or aggregate formation. Circular dichroism studies of the recombinant molecule show similar spectra at different pH values but are markedly different from that reported by Konno et al. (13) for a natural hirudin-variant. Our CD studies indicate the presence of about 60% beta sheet and the absence of alpha helix in the secondary structure of recombinant hirudin, in agreement with the conformation determined by NMR studies (17)

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