SEARCH · Search PubMed

Results for “Polyacrylamides”

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.

SourceResearch connectionFrom yearThrough year

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

At least 361 records · Page 20Linked to original sources

PubMed1987

Correlation between the cystic fibrosis protein detected by isoelectric focusing and a protein of 12 kDa detected by SDS-polyacrylamide gel electrophoresis.

We have studied both by isoelectric focusing and polyacrylamide gel electrophoresis in the presence of SDS, sera of individuals homozygous (25) and heterozygous (26) for cystic fibrosis and compared them to controls (13). As in our first study [1], the protein with a pI value of 8.4 called 'cystic fibrosis protein' or CFP, was found in about 70% of homozygous and carriers and in 15% of controls. When the same sera were analysed by polyacrylamide gel electrophoresis in the presence of SDS and after staining with Coomassie Blue, an additional protein with a molecular weight close to 12,000 (P12) was present in most of the sera containing CFP, suggesting a close relationship between the two proteins. By increasing the sensitivity of staining by using silver nitrate, P12 was detected with variable intensity in almost all sera of homozygotes and heterozygotes and at the level of traces in all normal sera. These data suggest that P12, like CFP, would be a normal serum protein quantitatively increased in affected subjects.

Adult↗

PubMed1988

Re-evaluation of normal human urinary proteins fractionated by one-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis.

Proteins in normal human urine were clearly fractionated into 26 bands with molecular weights from 14,000 to 230,000 by means of one-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) coupled with silver staining. The main band contained uromucoid, and the second main band had albumin. However, when urine samples from healthy persons were electrophoresed in the absence of SDS using polyacrylamide gel or agarose gel, or a cellulose acetate membrane, albumin but not uromucoid, frequently formed the main protein band. It is suggested that this is due to the complexing of uromucoid subunits to form a large molecule which cannot penetrate into the gel. In order to correctly fractionate all the proteins contained in normal human urine, it was concluded that it was best to treat a urine sample with SDS with pre-condensation, fractionate it by SDS-PAGE and stain fractionated proteins by a highly sensitive method such as silver staining.

Adult↗

PubMed1991

Affinity electrophoresis of alkaline phosphatase using polyacrylamide gels.

A method is described for the separation of liver and bone isoenzymes of alkaline phosphatase in serum using wheat germ lectin affinity electrophoresis in a polyacrylamide gel matrix. The electrophoretic mobilities of liver and intestinal isoenzyme are essentially not affected by lectin, but the bone enzyme is retarded and separated from the liver fraction. Affinity electrophoresis in polyacrylamide gel, combined with agarose gel electrophoresis, and a solid-phase linked antibody precipitation procedure for intestinal alkaline phosphatase allowed the various isoenzyme fractions, biliary, liver, bone and intestinal, to be quantitated.

Adult↗

PubMed1983

Resistance of chromatin superstructure to tryptic digestion modulated by conjugated polyacrylamide.

Soluble polyacrylamide conjugates have been used to modulate tryptic digestion of chromatin. Digestion of histones H1/H5 and H3 are mutually dependent and relatively independent of that of the core histones which are not significantly digested until 50-60% of H3 is degraded. H1/H5 and H3 are most exposed, H3 behaves as a "non-core' histone, its destruction appears to be the critical factor in the collapse of the chromatin superstructure during tryptic digestions. The digestion kinetics are explained by proposing that the initial sites of attack are in cavities much larger than the diameter of trypsin (4-5 nm). Procedures for the preparation of soluble polyacrylamide and its conjugation to trypsin are described.

Acrylic Resins↗

PubMed1987

Identification of different quaternary structures of beef heart cytochrome-c oxidase by two-dimensional polyacrylamide gel electrophoresis.

A two-dimensional gel electrophoresis is described to identify different quaternary structures of the heart cytochrome-c oxidase. Bovine enzyme was purified and separated by discontinuous gradient polyacrylamide gel electrophoresis under nondenaturing conditions in the 1st dimension into several discrete complexes and thereupon shown to be heterodisperse in Triton X-100 and dodecyl maltoside. A discontinuous SDS-polyacrylamide gel electrophoresis in the 2nd dimension was used to determine the subunit composition of the isolated complexes. One of these represents the intact enzyme with 12 different polypeptides while the others have an incomplete subunit composition.

Animals↗

PubMed1988

Identification and partial characterization of a new pancreatic cancer-related serum glycoprotein by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and lectin blotting.

The combination of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and peanut agglutinin lectin blotting has been used to identify a pancreatic cancer-related glycoprotein in serum. Its high molecular weight and its lectin-binding characteristics suggest that it probably is a mucin. Comparison with immunoblotting with Ca 19-9 antibody suggests that the epitopes for Ca 19-9 and peanut agglutinin may be variably expressed on different sites of the same mucin. The peanut agglutinin-binding glycoprotein was demonstrated in 12 of 34 pancreatic cancer sera, including four with normal Ca 19-9 assay, and none of 96 control sera, including sera from patients with obstructive jaundice and other cancers. These preliminary results suggest that it may become a useful addition to the current serum markers for pancreatic cancer. The technique of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and lectin blotting may well prove valuable in the search for other cancer-related glycoprotein markers.

Antigens, Neoplasm↗

PubMed1984

Application of SDS gradient polyacrylamide slab gel electrophoresis to analysis of apolipoprotein mass and radioactivity of rat lipoproteins.

An application of SDS gradient polyacrylamide slab gel electrophoresis to the analysis of lipoprotein polypeptides is described. The 10-15% polyacrylamide gradient provides a high degree of resolution and sensitivity resulting in a single separation of the major apoproteins which can be easily visualized. When combined with autofluorography, individual protein mass and radioactivity can be determined densitometrically while still retaining excellent resolution. Examples of rat lymph and plasma apolipoproteins are shown, and apparent heterogeneity of certain apoprotein subgroups is described.

Absorptiometry, Photon↗

PubMed1991

Preparative high-yield electroelution of proteins after separation by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and its application to analysis of amino acid sequences and to raise antibodies.

A method for the preparative high-yield electroelution of proteins from sodium dodecyl sulphate (SDS) polyacrylamide gel strips was established. The method consisted of SDS-polyacrylamide gel electrophoresis, detection of proteins with sodium acetate and electrophoretic elution at 200 V for 3 h by utilizing a horizontal flat-bed gel electrophoresis apparatus. Standard proteins with molecular masses of 14-66 kilodalton (cytochrome c, aldolase, ovalbumin and bovine serum albumin) were recovered with an average yield of 73.6 +/- 2.3%. A membrane-bound protein, rat skeletal muscle Ca(2+)-ATPase (100 kilodalton) was also well recovered (over 60%). This method was applicable to the purification of proteins required for N-terminal amino acid sequencing and to raise antibodies.

Amino Acid Sequence↗

PubMed1977

Detection of antigens and antibodies by an immuno-peroxidase method applied on thin longitudinal sections of SDS-polyacrylamide gels.

This paper describes a method for detection of antigens in thin sections of SDS-polyacrylamide gels. This method, called SGIP, involves longitudinal sectioning of SDS gels, fixation of the proteins in the gels, removal of the SDS, incubation of the sections with an antiserum and detection of antigens by the indirect immuno-peroxidase technique. The method is useful for assessing the affinity spectrum of a given antiserum against a heterogeneous mixture of proteins, and for the detection of proteins in tissue homogenates or other protein mixtures by means of well defined antisera. By applying the method to serial sections from a single SDS-polyacrylamide gel, a dilution dependent reactivity of antisera is demonstrated.

Acrylamides↗

PubMed1989

Polyacrylamide-streptavidin: a novel reagent for simplified construction of soluble multivalent macromolecular conjugates.

We have developed a soluble macromolecular conjugation reagent, polyacrylamide-streptavidin (PASA), for the simplified preparation of multivalent protein-protein conjugates. Soluble linear polyacrylamide, with a molecular weight of approximately 10(6), has carboxyl groups generated by limited alkaline hydrolysis. It is then activated with carbodiimide, separated from excess carbodiimide, and conjugated to streptavidin. The resulting conjugate, which has approximately 20 streptavidin residues per molecule, can bind biotinylated proteins to produce homo- or heteroconjugates of known composition. We have used this technique to prepare soluble multivalent heteroligating antibody conjugates that can bind either of two antigenically distinct cell lines, as well as reagents that specifically label murine tumor cells with different MHC class I antigens. The method is potentially useful for making multivalent arrays of epitopes for measuring low affinity interactions such as that between the T cell receptor and MHC molecules, as well as for making immunotoxins, tumor labelling conjugates, and complex immunogens.

Acrylic Resins↗

PubMed1985

Programmed aging or error catastrophe? An examination by two-dimensional polyacrylamide gel electrophoresis.

We have examined newly synthesized proteins in the young adult and in older populations of the nematode Caenorhabditis elegans using two-dimensional polyacrylamide gel electrophoresis (2D PAGE). A temperature-sensitive mutant strain, DH26, with a mean life span of about 15 days, under our conditions, was used to block progeny development. Nematodes of several different ages were pulse-labeled for 5 h, in vivo, with 35S-labeled E. coli, A subsequent 30-min chase with unlabeled E. coli served to rid the worms of endogenous labeled E. coli proteins. We resolve 700 or more proteins by 2D PAGE polyacrylamide gel electrophoresis of extracts of young nematodes. The patterns of these proteins are highly reproducible in comparisons of independent repeats of identical experiments. No new major proteins are synthesized at any time during the adult phase (4-22 days) nor are any of the most abundant proteins not made during this period. At our level of detectability (estimated as a satellite spot containing 4% of the amount of label in a major spot) we see no misincorporation of radioactive amino acids into newly synthesized proteins. These data are inconsistent with predictions by any one of several, so called, "error catastrophe" models of senescence and also show that modulation of the highest abundancy classes of proteins are also not involved in senescence.

Aging↗

PubMed1993

In situ detection of DNA-metabolizing enzymes following polyacrylamide gel electrophoresis.

We have presented several protocols for producing an in situ activity gel that allows detection of various DNA-metabolizing enzymes. Both nondenaturing polyacrylamide and SDS-polyacrylamide activity gel electrophoresis procedures were detailed. Combining the use of defined [32P]DNA substrates with product analysis, these procedures detected a wide spectrum of enzymatic activities. The ability to detect 7 different catalytic activities of 15 different enzymes provides encouragement for expanded applications. It is hoped that others will find this technique applicable for detecting these enzymes and other activities in different biological systems. The modification of DNA in situ and the creation of intermediate substrates within activity gels should prove extremely useful for dissecting the enzymatic steps of DNA replication, repair, recombination, and restriction, as well as the metabolic pathways of other nucleic acids.

Bacteriophage M13↗

PubMed1982

Behavior of unreduced polymeric and monomdric immunoglobulins in sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

Investigation of the electrophoretic behavior, in SDS-polyacrylamide and SDS-polyacrylamide-agarose gels, of IgMs and low mol. wt. Igs from four classes of vertebrates, as well as fragments derived from them, was carried out. A clear but unexpected straight-line relationship was observed for all Igs (and fragments) tested when relative mobility was plotted against log mol. wt for the unreduced molecules. Aberrant behavior of the low mol. wt Ig of Bufo marinus was shown to be due to the complete dissociation of the molecule into free light chains and heavy-chain dimers, in the presence of SDS.

Animals↗

PubMed1984

The antigenicity of myoglobin-related peptides synthesised on polyacrylamide and polystyrene resin supports.

Polyacrylamide resins [Atherton et al., Bioorg. Chem. 8, 351-370 (1979)] have been found suitable for solid-phase radioimmunoassay of peptides synthesised on the same supports; they are sufficiently stable during side-chain deprotection and swell sufficiently in aq. media to admit antibody molecules to the sites of peptide attachment. A re-examination of five synthetic peptide sequences corresponding to (15-21), (56-62), (94-99), (113-119) and (145-151) of beef myoglobin analogous to those delineated by Atassi [Immunochemistry 12, 423-438 (1975)] for sperm whale myoglobin shows that they all bind anti-beef myoglobin antibodies raised in rabbits, with binding capacities in the order V = III greater than IV greater than I = II. The resin-bound peptide (72-88) binds such antibodies even more extensively, as do certain sequential variants of peptide V. Other peptides, bound to polyacrylamide or polystyrene resins but unrelated to any of the five sequences and varying in size and amino acid composition and sequence were also tested with various antisera. It was concluded that the antibody binding properties of the 30 or so small peptides (two-seven residues) are dominated by their cationic and/or hydrophobic properties. In small peptides, therefore, antibody binding can be safely interpreted only in terms of general structural properties but not in terms of biological specificity. The latter property becomes assessable only with peptides representing larger areas of antigenic protein surfaces.

Acrylic Resins↗

PubMed1979

Estimation of polymerization efficiency in the formation of polyacrylamide gel, using continuous optical scanning during polymerization.

The Ferguson plot and 'quantitative' gel electrophoresis (based on the Ferguson plot) depend on a knowledge of accurate gel concentrations. The easiest way to estimate accuracy of gel concentrations, in terms of the degree of completion of the polymerization reaction which gives rise to a gel, is by spectrophometry. Making use of the apparatus for continuous optical scanning of polyacrylamide gels, the extent and rate of polymerization of cross-linked polyacrylamide were estimated by measuring the absorbance at 275 nm of the reaction mixture subsequent to free radical initiation of polymerization. Under appropriate conditions of monomer concentration, initiator levels and temperature, absorbance decreased monotonically after a lag period of 10 min, and after 20--30 min of reaction the absorbance reached a plateau value which provided a measure of polymerization efficiency. Application of a standard curve of absorbance vs. monomer concentration allowed one to quantitate concentrations of residual monomer throughout the course of polymerization. Under a set of arbitrary polymerization conditions (e.g. 6--20% total gel concentration), the reaction went to 63--96% completion. The rate of polymerization was approximately proportional to the square of the monomer concentration (2nd-order reaction kinetics). Absorbance decrease subsequent to the initiation of the polymerization reaction appeared suitable as a measure of efficiency of polymerization since: (a) absorbance spectra of monomers at 0.5 %T and residual monomers in a 10 %T gel, at a time when polymerization seemed terminated, coincided; (b) values of residual monomer obtained were reasonable (10--30%); (c) bimolecular reaction kinetics were found, in agreement with expectation; and (d) absorbance of incomplete polymerization mixtures, deficient in either initiators or monomers, was constant with time.

Acrylamides↗

PubMed1981

Quantitation of specific proteins in polyacrylamide gels by the elution of Fast Green FCF.

The quantitation of proteins in polyacrylamide gels stained with Fast green FCF has been investigated using a modification of the elution technique originally described by Fenner et al. (Fenner, C., Traut, R.R., Mason, D.T. and Wikman-Coffelt, J. (1975) Anal. Biochem. 63, 595--602) for Coomassie Blue and adapted by Medugorac (Medugorac, I. (1979) Basic Res. Cardiol. 74, 406--416) for use with proteins stained with Fast Green FCF. The elution of dye from stained protein was accomplished using 1.0 M NaOH instead of aqueous pyridine as required by the original method. The primary advantages of our modification are that the time required for protein quantitation has been considerably reduced and the use of toxic organic solvents has been eliminated. We have investigated the applicability of the method of several different proteins and our results indicate: (a) The quantity of Fast Green FCF eluted from specific proteins is proportional to the quantity of protein applied to the gel, but varies for each individual protein. (b) The method allows quantitation over a very wide range of protein (1--800 micrograms). (c) Quantitation of protein is independent of the width of the stained bands as well as acrylamide concentration. (d) The method is applicable to gels of many types including disc, slab and continuous gradient gels. (e) Protein can be estimated from the patterns obtained by two-dimensional polyacrylamide gel electrophoresis. (f) The presence of Triton X-100 in gel and protein sample does not affect quantitation; the method is applicable to gels containing SDS provided that SDS is removed prior to staining. (g) Precipitation of protein with 12.5% TCA following electrophoresis does not interfere with quantitation. (h) The reproducibility of the technique is excellent, with standard deviations being less than 10% of the mean in all cases. This method appears highly versatile but requires appropriate standards for the quantitation of individual proteins.

Animals↗

PubMed1984

Two-dimensional restriction mapping by digestion with restriction endonucleases of DNA in agarose and polyacrylamide gels.

We have studied with a number of bacterial restriction enzymes the conditions for digestion of DNA in agarose and polyacrylamide gels. The restriction endonucleases HpaII, MspI, HaeIII, HindIII, TaqI, HhaI, AluI, BamHI, EcoRI and SalI are capable of digesting DNA in agarose gels of low electroendosmosis and low sulfate concentration. All enzymes, except BamHI, are also capable of digesting DNA in polyacrylamide gels. With this method, rapid two-dimensional restriction mapping of genomes with low and high sequence complexity is possible.

Animals↗

PubMed1984

Yet another improved silver staining method for the detection of proteins in polyacrylamide gels.

Silver staining is very sensitive for detection of proteins in polyacrylamide gels and different procedures have been published. By combining and modifying some of the recipes, a very reproducible method, which is based upon staining with diamine complexes of silver, has been developed. The background staining is negligible and reduced silver does not precipitate on the gel surface. The technique works very well for sodium dodecyl sulfate-polyacrylamide gel electrophoresis in both homogeneous and in gradient gels as well as for two-dimensional (2-D) PAGE. It was possible to detect 1-10 ng of protein corresponding to approximately 50 pg/mm2, provided that a discontinuous buffer system was used, which gives sharp bands.

Acholeplasma laidlawii↗