Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “SDS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9Linked to original sources

Dermatitis herpetiformis: biochemical properties of the granular deposits of IgA in papillary dermis. Characterization of SDS-soluble IgA-like material and potentially antigen-binding IgA fragments released by pepsin.

Granular deposits of IgA in radioactively labeled thin slices of papillary dermis from 4-mm punch biopsies of clinically normal skin from patients with dermatitis herpetiformis were solubilized with sodium dodecyl sulfate (SDS) or peptic digestion at pH 4.5. Solubilized IgA-like material was isolated by immunoprecipitation and analyzed by electrophoresis in one and two dimensions in polyacrylamide gels containing SDS followed by autoradiography. SDS extracts contained IgA-like components corresponding to monomers, dimers, as well as higher polymers of IgA. A fraction of the SDS-soluble material behaved like IgA upon immunoprecipitation but could not be deaggregated to alpha- and light chains by reduction and alkylation, suggesting that it was present as irreversible aggregates with itself or with other proteins. Peptic digestion at pH 4.5 released fragments which were precipitated by antibodies to human alpha-chains and had molecular weights similar to the proteolytic fragments corresponding to F(ab)2 and Fab formed by peptic digestion of human monomeric IgA under the same conditions.

Antigens↗

Separation of cardiac myosin heavy chains by gradient SDS-PAGE.

Separation of alpha- and beta-myosin heavy chains (MHCs) in cardiac ventricles of rats by gradient sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was accomplished and compared with the separation of myosin isozymes obtained with pyrophosphate gels. Whole muscle homogenates were electrophoresed on a 4-9% linear gradient SDS polyacrylamide gel for 3-4 h. MHC bands were identified by the migration distance relative to a MHC standard and immunoblot results with a monoclonal antibody to MHC. The MHC bands were further identified as alpha and beta based on the electrophoretic mobility of ventricular homogenates from hypothyroid and hyperthyroid rats and ventricular and slow soleus skeletal muscle homogenates from control rats. The beta-MHC migrated faster than alpha-MHC, and laser densitometry revealed separate peaks when both MHCs were present. With homogenates containing MHC ranging from 0 to 100% alpha, the separation of MHCs with gradient SDS-PAGE correlated highly (r = 0.97) with separation of myosin isozymes by pyrophosphate gel electrophoresis. The SDS-PAGE technique reported herein is a quick, valid, and direct method for the identification and quantification of ventricular MHCs.

Animals↗

Rheological studies on the solubilization by the surfactant SDS of complexes between three acidic polysaccharides and an organic base chloride.

Developments in the solubilization of complexes between the cationic polymer, poly(hexamethylenebiguanidinium chloride) (PHMBH+Cl-) and acidic polysaccharides are reported. It was discovered that the anionic detergent sodium dodecyl sulphate (SDS) is an excellent solubilizer for these complexes, enabling several multi-component systems to be studied. SDS itself was shown to interact with PHMBH+Cl- to form a highly viscous solution. Maximum viscosity was obtained with a SDS:PHMBH+Cl- molar ratio of 15.6. SDS:PHMBH+Cl- at this ratio served as a good solubilizer for the acidic polysaccharides (sodium alginate, sodium carboxymethyl cellulose, and xanthan), forming highly viscous fluids. The effect of temperature on the viscosity of these solutions was also examined.

Alkalies↗

Evidence for structural and functional diversity among SDS-resistant SNARE complexes in neuroendocrine cells.

The core complex, formed by the SNARE proteins synaptobrevin 2, syntaxin 1 and SNAP-25, is an important component of the synaptic fusion machinery and shows remarkable in vitro stability, as exemplified by its SDS-resistance. In western blots, antibodies against one of these SNARE proteins reveal the existence of not only an SDS-resistant ternary complex but also as many as five bands between 60 and >200 kDa. Structural conformation as well as possible functions of these various complexes remained elusive. In western blots of protein extracts from PC12 cell membranes, an antibody against SNAP-25 detected two heat-sensitive SDS-resistant bands with apparent molecular weights of 100 and 230 kDa. A syntaxin antibody recognized only the 230 kDa band and required heat-treatment of the blotting membrane to detect the 100 kDa band. Various antibodies against synaptobrevin failed to detect SNARE complexes in conventional western blots and detected either the 100 kDa band or the 230 kDa band on heat-treated blotting membranes. When PC12 cells were exposed to various extracellular K(+)-concentrations (to evoke depolarization-induced Ca(2+) influx) or permeabilized in the presence of basal or elevated free Ca(2+), levels of these SNARE complexes were altered differentially: moderate Ca(2+) rises (</=1 microM) caused an increase, whereas Ca(2+) elevations of more than 1 microM led to a decrease in the 230 kDa band. Under both conditions the 100 kDa band was either increased or remained unchanged. Our data show that various SDS-resistant complexes occur in living cells and indicate that they represent SNARE complexes with different structures and diverging functions. The distinct behavior of these complexes under release-promoting conditions indicates that these SNARE structures have different roles in exocytosis.

Animals↗

Freeze-fracture replica electron microscopy combined with SDS digestion for cytochemical labeling of integral membrane proteins. Application to the immunogold labeling of intercellular junctional complexes.

We propose a new electron microscopic method, the sodium dodecylsulphate (SDS)-digested freeze-fracture replica labeling technique, to study the two-dimensional distribution of integral membrane proteins in cellular membranes. Unfixed tissue slices were frozen with liquid helium, freeze-fractured, and replicated in a platinum/carbon evaporator. They were digested with 2.5% SDS to solubilize unfractured membranes and cytoplasm. While the detergent dissolved unfractured membranes and cytoplasm, it did not extract fractured membrane halves. After SDS-digestion, the platinum/carbon replicas, along with attached cytoplasmic and exoplasmic membrane halves, were processed for cytochemical labeling, followed by electron microscopic observation. As an initial screening, we applied this technique to the immunogold labeling of intercellular junction proteins: connexins (gap junction proteins), occludin (tight junction protein), desmoglein (desmosome protein), and E-cadherin (adherens junction protein). The immunogold labeling was seen superimposed on the image of a fracture face visualized by platinum/carbon shadowing. The immunoreaction was specific, and only the structures where the proteins were expected were labeled. For instance, anti-occludin immunogold complexes were observed immediately adjacent to the tight junction strands on the protoplasmic and exoplasmic fracture faces. No significant levels of gold label were associated with non-tight-junctional regions of plasma membranes. The procedures of the SDS-digested freeze-fracture replica labeling and its potential significance are discussed.

Animals↗

Nanoparticle formation of poorly water-soluble drugs from ternary ground mixtures with PVP and SDS.

Poorly water-soluble drugs N-5159, griseofulvin (GFV), glibenclamide (GBM) and nifedipine (NFP) were ground in a dry process with polyvinylpyrrolidone (PVP) and sodium dodecyl sulfate (SDS). Different crystallinity behavior of each drug during grinding was shown in the ternary Drug/PVP/SDS system. However, when each ternary Drug/PVP/SDS ground mixture was added to distilled water, crystalline nanoparticles which were 200 nm or less in size were formed and had excellent stability. Zeta potential measurement suggested that the nanoparticles had a structure where SDS was adsorbed onto the particles that were formed by the adsorption of PVP on the surface of drug crystals. Stable existence of crystalline nanoparticles was attributable to the inhibition of aggregation caused by the adsorption of PVP and SDS on the surface of drug crystals. Furthermore, the electrostatic repulsion due to the negative charge of SDS on a shell of nanoparticles could be assumed to contribute to the stable dispersion.

Chemistry, Pharmaceutical↗

Stress tolerance test and SDS-PAGE for the analysis of urinary proteins in children and youths.

Excretion of urinary proteins (UP) is an important marker for the evaluation of patients with progressive renal disease. In order to analyze quantitative and qualitative variability of UP in relation to physical activity, we used standardized stress tolerance test and SDS-PAGE. Five urine samples were obtained from each patient at rest, during ordinary daily activity and after physical stress. Determination of total proteins was performed using Meulman's classic method with sulfosalicylic acid. UP were separated by ultrathin horizontal gradient SDS-PAGE according to Görg. There were 142 patients; 40 with poststreptococcal glomerulonephritis (PSGN), 11 with diabetes mellitus, 16 with chronic pyelonephritis and 75 who attended for investigation of asymptomatic proteinuria. Functional proteinuria was established in 42 subjects, who displayed maximal UP excretion during stress and the presence of apolipoprotein AI on SDS-PAGE. Children with PSGN showed no significant increase of UP during stress. Some children with diabetes mellitus (27%) and chronic pyelonephritis (47%) displayed microproteinuria or overt proteinuria after stress. Quantitative and qualitative changes in total UP excretion can be detected by stress tolerance test and SDS-PAGE. It remains to be seen whether stress tolerance test can identify children and youths who are at higher risk for disease progression.

Adolescent↗

Plum pox virus capsid protein mobility in SDS-polyacrylamide gel electrophoresis.

Slovak plum pox virus (PPV) isolates BOR-3 and KR-4 behaved atypically in polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE) of their capsid proteins (CPs). Whereas other tested PPV isolates could be sorted by SDS-PAGE into groups corresponding to the M or D strains, as controlled by restriction fragment length polymorphism (RFLP) analysis, the two above mentioned isolates behaved as the M strain according to RFLP analysis but not SDS-PAGE. Slight mobility differences were observed also among the isolates belonging to the D strain. SDS-PAGE of the CP thus cannot clearly distinguish between these two main PPV strains. BOR-3 isolate has been shown atypical also in its biological properties, and it reacted very weakly with a monoclonal antibody (MAb) recognizing well both M and D strains in immunoblot analysis.

Capsid↗

Value of SDS-polyacrylamide gel electrophoresis, small molecular weight proteins and alpha-1-acid glycoprotein for the diagnosis of tubular damage.

The low molecular weight proteins alpha-1-microglobulin, beta-2-microglobulin, retinol binding protein, alpha-1-acid glycoprotein and the SDS-polyacrylamide gel electrophoresis (SDS-PAGE) were estimated in 31 healthy children and compared to 81 urine samples of children with tubular damage (TD). The tubular damage was diagnosed clinically and established by beta-2-microglobulin determination. Means for healthy children were: beta-2-microglobulin 109 +/- 77 micrograms/l, alpha-1-microglobulin 0.39 +/- 0.0 mg/dl, retinol binding protein 0.49 +/- 0.0 mg/dl, alpha-1-acid glycoprotein 0.69 +/- 0.0 mg/dl. Means for children with TD were: beta-2-microglobulin 8530 +/- 14693, alpha-1-microglobulin 2.98 +/- 2.28 mg/dl, retinol binding protein 1.68 +/- 2.44 mg/dl and alpha-1-acid glycoprotein 2.79 +/- 3.44 mg/dl. Comparing the panel of healthy children with sick children (TD) we found the following: b2m t = 3.2, p = less than 0.0005, a1m t = 6.5, p = less than 0.0005, rbp t = 2.65, p = less than 0.0005, a-1-agp t = 3.4, p = less than 0.005. a1m revealed tubular damage in 77 out of 81 tubular disorders, the rbp in 25 out of 81 and alpha-1-acid glycoprotein showed tissue damage or inflammation in 33 out of 81 patients. SDS-PAGE revealed tubular damage in 46 out of 81 patients with TD. We can assay that alpha-1-microglobulin is a useful marker for tubular damage. The determination of retinol binding protein and alpha-1-acid glycoprotein is useless for this purpose. The SDS-PAGE, though a potent tool for the differential diagnosis between glomerular or tubular damage, alone is not a reliable assay for the diagnosis of TD.

Acidosis, Renal Tubular↗

Human C81 (alpha-gamma) polymorphism: detection in the alpha-gamma subunit on SDS-PAGE, formal genetics and linkage relationship.

The molecular basis of human C81 (alpha-gamma) polymorphism could be elucidated by immunoprecipitation of human C81 allotypes and separation of the alpha-gamma and beta subunits on sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) under nonreducing conditions. If the C8 molecules were completely reduced, C81 polymorphism was no longer detectable on SDS-PAGE. It is concluded that C81 variation depends on charge rather than molecular weight differences. Four C81 allotypes, the common A and B and two rare allotypes provisionally named A2 and B1, could be distinguished. The rare allotype A1 as detected by isoelectric focusing with subsequent C8 (alpha-gamma)-dependent functional overlay could no longer be visualized on SDS-PAGE. This allotype may therefore be elicited only in the intact C8 molecule. The beta-chain polymorphism named C82, probably also reflecting charge variation of the C8 molecule, could not be detected yet on SDS-PAGE. The distributions of C81 phenotypes and their respective allele frequencies were in good agreement with previously reported data. In the study of 30 families with 100 offspring, no deviation from the rule of at least four codominant alleles at one genetic locus was found. Linkage between C81 gene(s) and PGM1a encoded on chromosome 1 could be confirmed. The following estimates were obtained: (formula; see text) with S theta being the standard error of the maximum likelihood estimate theta. The new technique for allotyping human C81 at the subunit may provide a new tool for the differentiation of qualitative and quantitative variation of the eighth component of human complement.

Alleles↗

Diagnostic significance of SDS-PAA-electrophoresis of urinary proteins: different forms of proteinuria and their correlation to renal diseases.

Different types of urinary protein excretion may be recognized by determination of the proteins molecular weight. Beside chromatography different electrophoretic procedures have been applied to urinary proteins to study the underlying renal disease. The various zone electrophoreses separate merely by surface charge, proteins however covered by sodium dodecyl sulfate (SDS) migrate according to their molecular radius. So by SDS-polyacrylamide electrophoresis (SDS-PAe) macromolecular proteinurias (Mr 60,000- greater than 300,000 daltons) due to glomerular damage may be distinguished from micromolecular forms (Mr 10,000-70,000 d) due to tubular dysfunction. By densitometric quantitation of the separated Ig and transferrin an index of the glomerular selectivity is obtained, i.e. the capacity of the glomerular system, to retain serum proteins of a Mr above 150,000 d. By this procedure proliferative and degenerative glomerulopathies may be distinguished from minimal change disease, focal glomerular sclerosis and early membranous nephropathy; serial determinations of this selectivity index in the latter two disease entities show a gradual deterioration of glomerular protein handling with time. A glomerular proteinuria of even "physiological" quantity has been proved as early sign of renal involvment in systemic diseases; it may be detected earlier as for example the retinopathy in juvenile diabetics. Micromolecular proteinurias also occur at least in two forms: the typical tubular proteinuria (MW 10,000-70,000 d) is associated with acute or chronic severe tubular dysfunction as in interstitial nephritis and acute kidney failure; rejection episodes of kidney transplants lead to transient tubular proteinurias, too. The second form of micromolecular proteinuria (Mr 40,000-70,000 d) has been found frequently in association with a glomerular in diabetic and hypertensive glomerulosclerosis. By measuring clearances of the microproteins, the proteinuria with this pattern could be established as form independant from glomerular and tubular proteinurias. The constancy of the two micromolecular proteinurias led to the hypothesis of at least two selective mechanism of tubular protein resorption. SDS-PAe additionally allows the differentiation of extrarenal proteinurias, as caused by overflow, paraproteins, postrenal Ig-secretion or bleeding etc. In comparing clinical and in part histological data of about 2,000 patients suffering from kidney diseases the analysis of urinary proteins by this method has been proved as valuable non-invasive tool for diagnosis and follow-up.

Electrophoresis, Polyacrylamide Gel↗

Further characterization of filarial antigens by SDS polyacrylamide gel electrophoresis.

SDS (sodium dodecyl sulfate)-polyacrylamide gel electrophoresis of an antigen isolated from sera of Wuchereria bancrofti-infected patients and Setaria digitata antigen SD2-4 is reported. Both antigens showed carbohydrate (glycoprotein) staining. The W. bancrofti antigen had an apparent relative molecular mass of 35 000 while the S. digitata antigen SD2-4 migrated at the marker dye position on SDS-polyacrylamide gel electrophoresis. SDS treatment of these antigens did not abolish the precipitation reaction with antibody. In the case of W. bancrofti antigen, SDS treatment probably exposed hitherto hidden antigen epitopes.

Animals↗

Analysis of the low molecular weight nuclear polypeptide by isoelectrofocusing of nuclear proteins first separated by gel electrophoresis in SDS.

Some of the nuclear proteins, especially those tightly bound with nucleic acids, show a tendency to aggregate and some of them are also hydrophobic. Thus, SDS-containing buffers are useful for their analysis. The method of isoelectrofocusing of proteins separated by polyacrylamide gel electrophoresis in the presence of SDS was used for the analysis of the nuclear proteins. First, SDS-polyacrylamide gel electrophoresis of total chromatin proteins was conducted. The sample of the examined nuclear proteins after SDS-gel electrophoresis was isolated as a gel slice (thus corresponding to the particular molecular weight range) and used for isoelectrofocusing. This approach has been used for the analysis of about 19 kD nuclear polypeptide, tightly bound with DNA. The isoelectric point of this polypeptide has been estimated as 5.3.

Animals↗

Choosing a cut-off on the Severity of Dependence Scale (SDS) for amphetamine users.

In order to ascertain a cut-off score on the Severity of Dependence Scale (SDS) which is indicative of clinically significant amphetamine dependence, 327 regular amphetamine users were administered the SDS, along with the "Disorders resulting from the use of psychoactive substances" section of the Composite International Diagnostic Interview (CIDI) for DSM-III-R. Receiver operating characteristic (ROC) analysis was used in order to determine which cut-off score on the SDS allowed the best trade-off between sensitivity and specificity, when calibrated against the presence or absence of a DSM-III-R diagnosis of severe amphetamine dependence. Results suggest that the SDS has high diagnostic utility, and that a score of greater than four on the scale is indicative of problematic amphetamine use.

Adolescent↗

Conformation and interactions of bombolitin I analogues with SDS micelles and phospholipid vesicles: CD, fluorescence, two-dimensional NMR and computer simulations.

Bombolitins are five structurally related heptadecapeptides acting at the membrane level able to lyse erythrocytes and liposomes and to enhance the activity of phospholipase A2 (PLA2). In the presence of SDS or phospholipid vesicles bombolitins are able to form amphiphilic alpha-helical structures and this property seems to be the major determinant of bioactivity. In order to test the model of interaction between bombolitin I and membranes, an analogue was synthesized in which all the lysines were replaced by arginines: Ile-Arg-Ile-Thr-Thr-Met-Leu-Ala-Arg-Ile-Gly-Arg-Val-Leu-Ala-His-Val-NH2 ([Arg2,9,12, Ile10]bombolitin I). The design of this sequence allowed the synthesis of a second analogue through a specific postsynthetic dansylation at the epsilon-amino group of a lysine residue replacing the original leucine residue at position 7. The first analogue was fully characterized by CD and two-dimensional nmr in the presence of SDS or phospholipid vesicles. The peptide folds into an amphiphilic alpha-helical conformation with the helical segment spanning the central part of the sequence from Ile3 to His16. This behavior is identical to that observed for the native sequence. The replacement of lysine residues by arginine has no detectable effect on the conformational preference of the peptide chain. By CD and fluorescence spectroscopy measurements, the fluorophore-containing analogue [Arg2,9,12, Lys7 (epsilon-dansyl)] bombolitin I also folded into the alpha-helical conformation in the presence of SDS micelles or phospholipid vesicles. In particular, the dansyl fluorophore, which is located approximately in the middle of the apolar surface of the amphiphilic helix, is clearly buried in a hydrophobic environment when the peptide is bound to phospholipid vesicles. These findings support the hypothesis that the peptide helices are oriented parallel to the vesicle surface.

Amino Acid Sequence↗

Study on separation of aristolochic acid I and II by micellar electrokinetic capillary chromatography and competition mechanism between SDS and beta-cyclodextrin.

In this study, a rapid MEKC method using 40 mM sodium borate buffer containing 50 mM SDS as surfactant was developed for the analysis of aristolochic acid (AA) in Aristolochia plants. Baseline separation of AA-I and AA-II was achieved within 3 min with high separation efficiency, satisfactory sensitivity, repeatability, and recovery. Resolution between AA-I and AA-II is above 5 and great performance with higher than 200,000 theoretical plate numbers was obtained. The detection limits (based on 3 S/N) were both 1.0 microg/mL. Two kinds of AA in 35 herbal samples of Aristolochia plants were successfully determined. The competition mechanism between beta-CD and SDS was also investigated by changing the content ratio of beta-CD and SDS.

Antiviral Agents↗

Ion-pair assisted recovery of matrix-assisted laser desorption/ionization mass spectral signals from SDS-containing peptide-protein mixtures.

We have developed a simple and effective means of using alkylammonium ion-pairing agents, such as cetyltetramethylammonium bromide, to recover matrix assisted laser desorption/ionization mass spectrometric (MALDI-MS) signals from sodium dodecyl sulfate (SDS)-containing protein and peptide samples. A two-layer method of matrix preparation, with a bottom matrix layer of ion-pairing agents and a top matrix layer of SDS protein samples, is essential for reproducible MALDI mass spectra with good recovery. Both buffer ions and ion-pairing agents have profound effects on signal recovery and can be rapidly and systematically optimized. This practical technique, termed ion-pair assisted recovery (IPAR), is compatible with major SDS-based biotechniques and can be easily incorporated into high-throughput proteomic analysis.

Buffers↗

Composition of human zona pellucida as revealed by SDS-PAGE after silver staining.

The macromolecular composition of zona pellucida (ZP) isolated from human oocytes and embryos was characterized by one- and two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (1-D- and 2-D-SDS-PAGE) under reducing conditions after silver staining. ZP specimens obtained after in vitro fertilization were removed from pools of heavily fragmented embryos and inseminated oocytes that failed to fertilize. For unfertilized oocytes, two major bands with an apparent molecular weight of, respectively, 96 and 76-54 kDa were observed after 1-D-SDS-PAGE and silver staining. When ZP were isolated from fragmented embryos, the electrophoretic pattern showed a marked attenuation of the 96-kDa band. Silver-stained 2-D-SDS-PAGE analysis of ZP components from unfertilized oocytes revealed the presence of four protein trains: ZP1 (Mr = 92-80 kDa, pl = 4.9-5.9), ZP2 (Mr = 66-58 kDa, pl = 5.0-6.0), ZP3H (high) (Mr = 72-58 kDa, pl = 3.5-5.1), and ZP3L (low) (Mr = 62-54 kDa, pl = 3.5-5.1). The human ZP3 family (ZP3H and ZP3L) showed marked heterogeneity. Fertilization-associated changes were apparent in the electrophoretic pattern. ZP1 (Mr = 92-86 kDa, pl = 5.0-5.8) displayed a dramatic decrease in intensity, and a new component had migrated to a position similar to that of ZP2. This modification may have been responsible for one aspect of the zona reaction, and could have contributed to a zona block to polysperma.

Electrophoresis, Gel, Two-Dimensional↗