scholarly journals The electrical conductivities of aqueous solutions of sodium dodecyl sulphate and sodium hexadecyl sulphate at different temperatures

The classical work of McBain on the electrical conductivity and other properties of aqueous solutions of the soaps led him to postulate the formation of the ionic micelle. This aggregate of ions has a greater mobility than that of the ions composing it, and its formation accounts for the characteristic increase in conductivity exhibited by colloidal electrolytes. The conception has resulted in great advance in the study of all classes of colloidal electrolytes e. g ., protein and gelatine salts, dyes, and other substances of high molecular weight.

2014 ◽  
Vol 6 (5) ◽  
pp. 63-67
Author(s):  
A. Gomathiyalini ◽  
◽  
K. Renuka Devi ◽  
S. Rathika ◽  
S. Geetha

1976 ◽  
Vol 156 (1) ◽  
pp. 143-150 ◽  
Author(s):  
R H Quarles

Rats (14 days old) were injected with [14c]fucose and young adult rats with [3H]fucose in order to label the myelin-associated glycoproteins. As previously reported, the major [14C]fucose-labelled glycoprotein in the immature myelin had a higher apparent molecular weight on sodium dodecyl sulphate/polyacrylamide gels that the [3H]fucose-labelled glycoprotein in mature myelin. This predominant doubly labelled glycoprotein component was partially purified by preparative gel electrophoresis and converted to glycopeptides by extensive Pronase digestion. Gel filtration on Sephadex G-50 separated the glycopeptides into several clases, which were designted A,B, C AND D, from high to low molecular weight. The 14C-labelled glycopeptides from immature myeline were enriched in the highest-molecular-weight class A relative to the 3H-labelled glycopeptides from mature myelin. Neuraminidase treatment of the glycoprotein before Pronase digestion greatly decreased the proportion of glycopeptides fractionating in the higher-molecular-weight classes and largely eliminated the developmental differences that were apparent by gel filtration. However, neuraminidase treatment did not decrease the magnitude of the developmental difference revealed by electrophoresing the intact glycoprotein on sodium dodecyl sulphate gels, although it did decrease the apparent molecular weight of the glycoprotein from both the 15-day-old and adult rats by an amount comparable in magnitude to that developmental difference. The results from gel filtration of glycopeptides indicate that there is a higher content of large molecular weight, sialic acid-rich oligosaccharide units in the glycoprotein of immature myelin. However, the higher apparent molecular weight for the glycoprotein from 15-day-old rats on sodium dodcyl sulphate gels is not due primarily to its higher sialic acid content.


1983 ◽  
Vol 29 (2) ◽  
pp. 280-287 ◽  
Author(s):  
J. W. Coulton ◽  
D. T. F. Wan

Membrane proteins fom the cell envelope of Haemophilus influenzae type b ATCC 9795 were examined by sodium dodecyl sulphate – polyacrylamide gel electrophoresis. When envelopes were extracted with a phosphate-based buffer containing 2% Triton X-100, a major protein of molecular weight 43 000 was detected in fractions containing cytoplasmic membrane proteins. The cell wall material which was Triton X-100 insoluble contained six major proteins of molecular weights 46 000, 40 000, 36 000, 30 000, 27 000, and 16 000. One of these proteins showed a shift in molecular weight from 27 000 to 36 000 when it was heated over a temperature range from 50 °C to 100 °C in buffer containing 2% sodium dodecyl sulphate, 5% 2-mercaptoethanol. This alteration in mobility could be demonstrated either by the membrane-bound form of the protein or by a detergent-soluble form of the protein. Enriched preparations of the 36 000 molecular weight form were obtained by a series of purification steps. Extraction of the Triton X-100 insoluble material with buffer containing 2% Triton X-100, 5.0 mM EDTA yielded chiefly one major protein molecular weight 30 000 and many minor protein species. Pretreatment of the Triton X-100 insoluble fraction with lysozyme followed by extraction with buffer containing 2% Triton X-100, 5.0 mM EDTA released two proteins of molecular weights 16 000 and 27 000 and few minor proteins. By these operational manipulations, the proteins of molecular weights 16 000 and 27 000 may be considered as peptidoglycan-associated proteins.


1983 ◽  
Vol 59 (1) ◽  
pp. 81-103 ◽  
Author(s):  
R. Crossley ◽  
D.V. Holberton

Proteins from the axonemes and disc cytoskeleton of Giardia lamblia have been examined by sodium dodecyl sulphate/polyacrylamide gel electrophoresis. In addition to tubulin and the 30 X 10(3) molecular weight disc protein, at least 18 minor components copurify with the two major proteins in Triton-insoluble structures. The most prominent minor bands have the apparent molecular weights of 110 X 10(3), 95 X 10(3) and 81 X 10(3). Protein of 30 X 10(3) molecular weight accounts for about 20% of organelle protein on gels. In continuous 25 mM-Tris-glycine buffer it migrates mostly as a close-spaced doublet of polypeptides, which are here given the name giardins. Giardia tubulin and giardin have been purified by gel filtration chromatography in the presence of sodium dodecyl sulphate. Well-separated fractions were obtained that could be further characterized. Both proteins are heterogeneous when examined by isoelectric focusing. Five tubulin chains were detected by PAGE Blue 83 dye-binding after focusing in a broad-range ampholyte gel. Giardin is slightly less acidic than tubulin. On gels it splits into four major and four minor chains with isoelectric points in the pI range from 5.8 to 6.2. The amino acid composition of the giardin fraction has been determined, and compared to Giardia tubulin and a rat brain tubulin standard. Giardins are rich in helix-forming residues, particularly leucine. They have a low content of proline and glycine; therefore they may have extensive alpha-helical regions and be rod-shaped. As integral proteins of disc microribbons, giardins in vivo associate closely with tubulin. The properties of giardins indicate that in a number of respects - molecular size, charge, stoichiometry - their structural interaction with tubulin assemblies will be different from other tubulin-accessory protein copolymers studied in vitro.


2010 ◽  
Vol 2 (2) ◽  
pp. 313-321 ◽  
Author(s):  
K. M. A. Haque ◽  
M. S. Hussain

Nano-sized nickel particles have been synthesized by a bottom-up approach, using hydrazine as the reducing agent in the presence of an anionic surfactant - sodium-dodecyl sulphate (SDS). The effect of adding a nonionic polymer -polyvinylpyrrolidone (PVP) with an anionic surfactant has been studied at two different temperatures; the rate of reduction increased as the reaction temperature was increased from 60 to 100°C. These nano-aggregated nickel particles were characterized by using SEM with EDX facilities and TEM. TEM characterization showed the presence of spherical Ni particles as fine as 10nm in diameter. However, the SEM images showed a very spiky morphology, very small spherical shaped objects were clearly observed within these spiky structures. The combination of SDS/PVP reaction produced nano-sized nickel particles which were much finer than the reactions where SDS was used on its own. PVP has shown some dispersion power, and was found to be capable of preventing nickel particles from gradual agglomeration.  Keywords: Bottom-up; SDS; PVP; 10 nm. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.       DOI:10.3329/jsr.v2i2.3261               J. Sci. Res. 2 (2), 313-321 (2010) 


1981 ◽  
Vol 197 (2) ◽  
pp. 519-522 ◽  
Author(s):  
E G Afting ◽  
M L Recker

Cathepsin D was purified by two-step affinity chromatography on concanavalin A- and pepstatin-Sepharose. The main purification was achieved by washing the enzyme bound to the pepstatin-Sepharose column with buffered 6 M-urea. This step separated cathepsin D from all low- and high-molecular-weight impurities. Although the 1700-fold purified acid proteinase was homogeneous on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, it still showed microheterogeneity.


1994 ◽  
Vol 11 (3) ◽  
pp. 161-174 ◽  
Author(s):  
Fouad Taha ◽  
M.B. Saleh ◽  
K.M.E. Attyia ◽  
M.M.R. Khalaf

The surface charge properties of cassiterite and quartz particles in primary amine hydrochloride, sodium oleate, sodium dodecyl sulphate, phenyl disodium orthophosphate, 4-nitrophenyl disodium orthophosphate and starch solutions have been monitored using particle microelectrophoresis. The zeta potentials of the oxides and their isoelectric points (IEPs) were determined as a function of pH in the presence of different surfactant concentrations. In general, cassiterite and quartz particles acquired a negative charge in the various aqueous solutions and were dramatically influenced by both pH and the presence of surfactants. The magnitude of the surface charge varied considerably and could adopt positive or negative values. The IEPs also varied depending on the solution properties.


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