Showing papers on "Gel electrophoresis published in 1971"
TL;DR: The retardation coefficient is shown both empirically and theoretically to be a uniform function of molecular weight of protein-SDS complexes over specified ranges, providing a rationale for determining molecular weight from plots of the negative logarithm of relative mobility against molecular weight.
1,904 citations
TL;DR: Because of the importance of intrinsic charge and conformation, the system, although allowing a first approximation in molecular weight determination, may also be applicable to peptide “mapping,” particularly for “insoluble” peptide mixtures with prominent hydrophobic association, such as encountered in cellular membranes, viruses, and proteolytic digests.
1,644 citations
01 Jan 1971
TL;DR: This chapter describes polyacrylamide gel electrophoresis of viral proteins in gels, which are extensively used at the present time and are more homogeneous and stable than other commonly used materials.
Abstract: Publisher Summary This chapter describes polyacrylamide gel electrophoresis of viral proteins. Viral structural and nonstructural proteins are agents of expression for the information carried in viral nucleic acid genomes. An understanding of the behavior of a virus requires its proteins be characterized. For this purpose and for the characterization of nucleic acids, electrophoresis in gels is the most sensitive and versatile method. The genetic content and number of proteins of most viruses is relatively small compared even to simple cells. Two aspects of gels as supporting media for zonal electrophoresis experiments are responsible for the dramatic separations. First, as simple anti-convection media gels, they are more homogeneous and stable than other commonly used materials. Second, with the correct choice of gel concentrations, the spaces in the gel matrix are of similar dimensions to macromolecules so that selective sieving occurs during the electrophoretic migration. Gels composed of polyacrylamide are extensively used at the present time.
1,517 citations
TL;DR: The products of four of the six genes involved in bacteriophage T4 tail fibre assembly by sodium dodecyl sulphate-acrylamide gel electrophoresis of tail fibre mutant lysates and particles purified from them are identified, allowing the formulation in greater detail of the early stages of the fibre assembly pathway.
925 citations
TL;DR: Recovery of activity could only be achieved when the required components were mixed prior to removal of urea, suggesting that one or more of these proteins may refold improperly on removal of Urea unless the other components are present.
580 citations
TL;DR: Previous molecular weights proposed for the human erythrocyte membrane glycoprotein utilizing SDS gel electrophoresis are probably incorrect and a new value of 55,000 is proposed based on corrected SDS-gel data.
509 citations
TL;DR: Results indicate that colchicine-sensitive cytoplasmic microtubules are heteropolymers.
Abstract: Colchicine-binding protein, considered to be microtubule protein, was purified from chick embryo brain by column chromatography in one step on DEAE-Sephadex The active colchicine-binding unit is a dimer, MW 115,000 ± 5000, which is composed of two nonidentical monomeric units The two subunits are separable by urea-acrylamide gel electrophoresis after they have been reduced and acetylated Sodium dodecyl sulfate-acrylamide gel electrophoresis indicates that the subunits both have molecular weights of 55,000 ± 2000 The amino-acid compositions of the two subunits showed statistically significant differences in six amino-acid residues These results indicate that colchicine-sensitive cytoplasmic microtubules are heteropolymers
240 citations
TL;DR: A standard curve of histone mobility versus the logarithm of molecular weight was obtained and it was found to be different from the standard protein curve commonly used for molecular weight determination with this technique.
229 citations
TL;DR: Gel electrophoresis in sodium dodecyl sulfate and gel filtration in guanidine indicate that native concanavalin A contains several molecular species.
Abstract: Gel electrophoresis in sodium dodecyl sulfate and gel filtration in guanidine. HCl indicate that native concanavalin A contains several molecular species. An intact subunit of molecular weight 27,000 has been purified from this mixture. In addition, three fragments of the intact subunit have been isolated and characterized. A working model of the concanavalin A molecule has been constructed based on pairings of the intact subunit and of subunits consisting of fragments.
194 citations
TL;DR: Using tobacco mosaic virus and Escherichia coli rRNA as standards, it was found that Qβ and R17 phage RNA's have molecular weights of 1500 000 and 1300 000, respectively.
192 citations
TL;DR: Particles of the BEL(Ao) strain of influenza virus were disrupted with cold sodium dodecyl sulphate, and the hemagglutinin subunits were found to contain two different polypeptide chains with molecular weights of approximately 60,000 and 21,000.
TL;DR: Reaction of proteins with dansyl chloride in mildly alkaline SDS systems at high mole ratios of dANSyl chloride to protein yields dansyated proteins that can be run in SDS gel electrophoresis systems with no significant change in protein mobility.
TL;DR: [3H]-l-fucose seems to be a specific label for HeLa cell plasma membranes, which are characterized by phase and electron microscopy and by the use of radioactive precursors to RNA, protein, glycoprotein, and lipid.
TL;DR: Amino acid and carbohydrate analyses indicate that the A protein of lactose synthetase is a glycoprotein with about 12% by weight carbohydrate, which suggests that the enzyme is not composed of subunits.
TL;DR: Both fetal and cancerous liver cells produce α‐fetoproteins which are structurally indistinguishable and probably identical, and these proteins are probably identical.
Abstract: Alpha fetoprotein (AFP) from human fetuses and hepatocellular carcinoma patients was isolated and characterized. AFP isolated from human fetuses and patients with hepatocellular cancer gave a reaction of immunological identity in immunodiffusion. The electrophoretic mobilities of these proteins in polyacrylamide gels were identical. The formation of a 140000-molecular-weight form was also similar in the fetal and carcinoma AFPs. Gel electrophoresis in the presence of sodium dodecyl sulfate gave a molecular weight of 70000 for the single polypeptide chain of both proteins. Under these conditions the mobility of the AFPs was considerably faster than that of human transferrin and just slower than that of bovine albumin. Amino acid compositions of the 2 AFPs were similar. Peptide maps of tryptic digest of reduced and alkylated AFPs were compared and each AFP showed 30 peptides. The location of each peptide seemed to be the same on the maps of the 2 proteins. Also indistinguishable were peptide maps prepared from heat-saturated protein samples. Comparison of carbohydrate analyses of the fetal and cancer AFPs also revealed close similarity in the total amount of carbohydrate (4%) and in the relative amounts of hexose (2.2 vs. 2 for fetal and cancer respectively) hexosamine (1.2 vs. 1.1) and sialic acid (.9 vs. .9 or 2 moles of sialic acid/mole of protein). Thus both fetal and cancerous liver cells produce AFP which is structurally indistinguishable and probably identical.
TL;DR: The average pore diameter of the gels was sufficient to allow penetration of all but the very largest proteoglycans of articular cartilage, making it possible to distinguish “aggregates” from disaggregated molecules.
TL;DR: Ribosomal proteins isolated from 30S subunits of E. coli in four laboratories have been correlated by using two-dimensional gel electrophoresis, immunological techniques, amino acid compositions and molecular weights.
Abstract: Ribosomal proteins isolated from 30S subunits ofE. coli in four laboratories have been correlated by using two-dimensional gel electrophoresis, immunological techniques, amino acid compositions and molecular weights. The results are given in the Table. A common nomenclature for naming 30 S ribosomal proteins and their genetic loci is proposed.
TL;DR: Hen Oviduct RNA can direct the synthesis of the major oviduct protein, ovalbumin, in a cell-free system derived from rabbit reticulocytes, and messenger RNA activity appears to sediment in a sucrose gradient on the low molecular weight side of the 18 S ribosomal RNA.
TL;DR: To obtain information on the relationship between a carcino‐fetal protein, α‐fetoprotein, fetal proteins from other species and other human serum proteins including the fetoprotein in patients with hepatocellular cancer,α‐ Fetoprotein was purified and characterized from the serum of human fetuses.
Abstract: Alpha fetoprotein (AFP) which comprises 1/10th of all fetal proteins was purified and characterized from serum of human fetuses. AFP could be partially separated from other serum proteins by electrofocusing and AFP formed a single peak at pH 4.75. An anti-AFP serum was used for immunochemical purification of AFP from fetal sera. The purified AFP gave 2 electrophoretically distinct components which in immunodiffusion acted identically with anti-AFP antibodies. These were separated by gel filtration and the molecular weights obtained were 140000 and 70000 respectively for the slower and faster electrophoretic bands. The larger fetoprotein was not present in native serum but appeared after repeated freezing and thawing. AFP that had been dissociated into its polypeptide components by sodium dodecyl sulfate however gave only a single band in gel electrophoresis and molecular weight calibration gave a 70000 value for the single fetoprotein polypeptide. AFP amino acid composition is presented tabularly. AFP contained 4.3% carbohydrate consisting of 2.2% hexose 1.2% hexosamine and .9% sialic acid.
TL;DR: This method permits assessment for the first time of the total protein complement of the myofibril, with minimization of losses occurring during extraction procedures, and should further the understanding of the composition and biosynthesis of muscle.
TL;DR: Although some ribosomal and transfer RNAs are synthesized during amino acid starvation, the RNA is considerably enriched in messenger RNA, and the major effect of amino acid deprivation is the preferential curtailment of stable RNA synthesis.
TL;DR: It is shown that the sodium dodecyl sulphate—acrylamide method also fails for proteins of highly negative or positive charge, and some advantages result from the reaction of samples with dansyl chloride prior to electrophoresis to give strongly fluorescent zones.
TL;DR: Study employing colchicine binding, precipitation with vinblastine sulfate, and acrylamide gel electrophoresis confirm earlier proposals that Arbacia punctulata and Lytechinus pictus eggs and embryos contain a store of microtubule proteins, and provides the first protein encoded by stored or "masked" mRNA in sea urchin embryos to be identified.
Abstract: Studies employing colchicine binding, precipitation with vinblastine sulfate, and acrylamide gel electrophoresis confirm earlier proposals that Arbacia punctulata and Lytechinus pictus eggs and embryos contain a store of microtubule proteins. Treatment of 150,000 g supernatants from sea urchin homogenates with vinblastine sulfate precipitates about 5% of the total soluble protein, and 75% of the colchicine-binding activity. Electrophoretic examination of the precipitate reveals two very prominent bands. These have migration rates identical to those of the A and B microtubule proteins of cilia. These proteins can be made radioactive at the 16 cell stage and at hatching by pulse labeling with tritiated amino acids. By labeling for 1 hr with leucine-3H in early cleavage, then culturing embryos in the presence of unlabeled leucine, removal of newly synthesized microtubule proteins from the soluble pool can be demonstrated. Incorporation of labeled amino acids into microtubule proteins is not affected by culturing embryos continuously in 20 µg/ml of actinomycin D. Microtubule proteins appear, therefore, to be synthesized on "maternal" messenger RNA. This provides the first protein encoded by stored or "masked" mRNA in sea urchin embryos to be identified.
TL;DR: A modified basic protein, film method of spreading RNA in a strongly denaturing solvent for examination in the electron microscope has been developed and applied to determine the size of the HeLa mitochondrial specific ribosomal RNA components.
TL;DR: Chick embryo lethal orphan (CELO) virus, an oncogenic avian adenovirus, and one of its antigens (the hexon) were purified from infected allantoic fluid and some of their properties were studied.
TL;DR: The amino acid composition was determined directly from protein bands from Amido Schwarz stained polyacrylamide gels using this method to help in the analysis of isozymes and in determining the composition of subunits separated under dissociating conditions.
TL;DR: It has been found from a comparison of the electrophoretic mobilities on SDS-acrylamide gels of unmaleylated, maleylations, and demalylated proteins that electroph theoretically mobilities are affected by changes in charge as well as by change in molecular size.
TL;DR: Three major structural proteins were found in adenovirus-associated virus (AAV) type 3H virions which were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis.
Abstract: Three major structural proteins were found in adenovirus-associated virus (AAV) type 3H virions which were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The molecular weights of the polypeptides were determined to be approximately 66,000 (VP1), 80,000 (VP2), and 92,000 (VP3). The component having a molecular weight of 66,000 comprised about 80% of the total virion protein in the major AAV-3H particle, and the other two components comprised about 10% each. Proteins of the same molecular weight were found in the minor dense AAV-3H virion, but the 80,000- and 92,000-molecular-weight components were present at about one-half the concentration. The AAV-3H virion contains about 72 molecules of VP1 and 8 and 7 molecules of VP2 and VP3, respectively.
TL;DR: The chromatin of these interphase nuclei has a specific, ordered structure which is probably determined both by the chromatin composition and interaction between chromatin and nuclear membrane, and does not appear to directly regulate the capacity of the DNA to support RNA synthesis.
TL;DR: Preparations of both D and I forms of glycogen synthase (UDPG:glycogen α-4-glucosyltransferase, EC 2.4.1.11) have been demonstrated to be virtually homogeneous by gel electrophoresis in sodium lauryl sulfate.