共查询到20条相似文献,搜索用时 15 毫秒
1.
Sallie O. Hoch 《Biochemical and biophysical research communications》1982,106(4):1353-1358
Human plasma fibronectin was subjected to limited proteolysis, and its DNA-reactive polypeptides were distinguished using the protein blot technique. The polypeptides were separated electrophoretically by SDS gel electrophoresis, transferred to nitrocellulose and probed with radiolabeled human lymphocyte DNA. The major DNA-binding domains identified by the protein blots were comparable to the polypeptides identified using affinity chromatography on DNA-cellulose. 相似文献
2.
Association of adenovirus type 2 early proteins with a soluble complex that synthesizes adenovirus DNA in vitro 总被引:3,自引:0,他引:3
H M Rho Y H Jeng W S Wold M Green 《Biochemical and biophysical research communications》1977,79(2):422-428
A soluble Ad2 DNA synthesizing complex was prepared from Ad2-infected KB cell nuclei and purified by exclusion chromatography on a BioGel A-50m column. The purified complex was able to synthesize DNA from all regions of the virus genome, as indicated by RI restriction endonuclease analysis of labeled DNA. Experiments were performed to identify Ad2-induced early polypeptides present in the complex. Ad2-infected and mock-infected cells were labeled with [35S]methionine 7–10 h postinfection, then incubated for 8 h to allow the 35S-labeled early polypeptides to become associated with the complex. The polypeptides in the purified complex and each of the cell fractions were identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis and autoradiography. The major components of the purified complex were the 73K DNA binding phosphoprotein and 11K, two adenovirus 2-induced early polypeptides. The 11K has a preferred nuclear location. Small quantities of other Ad2-induced early proteins, 21K, 15K, and possibly 8.3K were also associated with the complex. 相似文献
3.
Sonicated DNA has been covalently attached to Sepharose 4B by a carbodiimide method [Rickwood, P. (1972) Biochim. Biophys. Acta269, 47–50] which minimizes modification of the DNA and matrix. Columns of this material have been used to study the interaction between cationic polypeptides and DNA. When poly(l-lysine) is bound to such columns at low ionic strength and then eluted with a linear salt gradient the polypeptide elutes over a broad range of salt concentration, presumably reflecting different strengths of interaction with various sites on the DNA. The broadness of the elution profile cannot be attributed to heterogeneity in the poly(l-lysine) sample but rather to the content of various DNA sites. Studies with other polypeptides, poly(l-Lys79, l-Leu21) and poly-(l-Lys-l-Ala-Gly), as well as studies at different temperatures, have helped to clarify the possible roles of conformational mobility, polypeptide hydrophobicity, and the presence of contiguous lysines in determining the strength of interaction of polypeptides and proteins with DNA sites. 相似文献
4.
Ping C. Hu Yuan-shen Huang Judith A. Graham Donald E. Gardner 《Biochemical and biophysical research communications》1981,103(4):1363-1370
Proteins of were separated by SDS-polyacrylamide gel electrophoresis and transferred to a nitrocellulose sheet by blotting. Sera obtained from infected hamsters and immunized rabbits were then incubated with the nitrocellulose strips. Proteins which are capable of eliciting antibodies were detected by indirect immunoradioautography using 125I-labeled antisera against hamster or rabbit IgG. Antibodies to seven immunogens were demonstrated in the sera of hamsters infected with by inhalation, while many more proteins were found to be capable of stimulating antibodies in rabbits immunized parenterally with mycoplasmas. This method should prove useful for identifying those components of a microorganism which elicit antibody responses and contribute to the protective state. 相似文献
5.
Gregory W. Kamykowski Deane F. Mosher Laszlo Lorand John D. Ferry 《Biophysical chemistry》1981,13(1):25-28
Shear moduli and creep compliances have been measured for four types of clots of human fibrin (about 7 ) clotted with and without human plasma fibronectin (usually 1.2 ). Fine clots (with little lateral aggregation of the fibrin protofibrils) were formed at pH 8.5, ionic strength 0.45 ; coarse clots (with substantial lateral aggregation) were formed at pH 7.5, ionic strength 0.15; in both cases with and without ligation by fibrinougase. In fine clots, the addition of fibronectin without ligation scarcely affected the shear modulus; with ligation, the modulus was decreased by a factor of 0.48. In coarse clots, the shear modulus was increased by addition of fibronectin. The increase was by a factor of 2.0 without ligation and by a factor of 2.4 with ligation. Creep and creep recovery in clots formed with and without fibronectin were similar except for the scale factor represented by the change in modulus. 相似文献
6.
Direct binding studies do not support the existence of true alpha-adreno-receptors in rat white fat cells 总被引:1,自引:0,他引:1
Y Giudicelli N R Thotakura D Lacasa R Pecquery B Agli 《Biochemical and biophysical research communications》1981,100(2):621-628
The complexity of mitochondrial translation products in mouse liver and Ehrlich ascites tumor cells have been studied using a mitoplast system active in 35S methionine incorporation. Electrophoretic analysis on gradient polyacrylamide-SDS gels and urea-SDS gels under highly dissociating conditions show that both of the mitochondrial systems synthesize about 22 polypeptides. Many of these 35S labeled products compare with the polypeptides predicted by the DNA sequence analysis data reported by Anderson (1). 相似文献
7.
Martin Weinberger Robert S. Greene Cheryl R. Nash Charles E. Helmstetter 《Biochemical and biophysical research communications》1984,125(2):600-605
Extracts from capable of supporting -dependent DNA replication have been examined with a protein blotting protocol to identify DNA-binding proteins. Four polypeptide chains with apparent affinity for DNA were detected. 相似文献
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The immunologic cross-reactivity of the α and α+ forms of the large subunit and the β subunit of the ( from brain and kidney preparations was examined using rabbit antiserum prepared against the purified holo lamb kidney enzyme. As previously reported by Sweadner ((1979) J. Biol. Chem. 254, 6060–6067) phosphorylation of the large subunit of the ( in the presence of Na+, Mg2+, and [ revealed that dog and, very likely, rat brain contain two forms of the large subunit (designated α and α+) while dog, rat, and lamb kidney contain only one form (α). The cross-reactivity of the α and α+ forms in these preparations was investigated by resolving the subunits by SDS-polyacrylamide gel electrophoresis. The separated polypeptides were transferred to unmodified nitrocellulose paper, and reacted with rabbit anti-lamb kidney serum, followed by detection of the antigen-antibody complex with 125I-labeled protein A and autoradiography. By this method, the α and α+ forms of rat and dog brain, as well as the α form found in kidney, were shown to cross-react. In addition, membranes from human cerebral cortex were shown to contain two immunoreactive bands corresponding to the α and α+ forms of dog brain. In contrast, the brain of the insect Manduca sexta contains only one immunoreactive polypeptide with a molecular weight intermediate to the α and α+ forms of dog brain. The β subunit from lamb, dog and rat kidney and from dog and rat brain cross-reacts with anti-lamb kidney ( serum. The mobility of the β subunit from dog and rat brain on SDS-polyacrylamide electrophoresis gels is greater than the mobility of the β subunit from lamb, rat or dog kidney. 相似文献
10.
Assembly of the vesicular stomatitis virus envelope: incorporation of viral polypeptides into the host plasma membrane 总被引:17,自引:0,他引:17
A E David 《Journal of molecular biology》1973,76(1):135-148
Incorporation of viral polypeptides into the host plasma membrane is an essential step in the formation of the lipoprotein envelope of vesicular stomatitis virus. A quantitative study of this process was carried out using a double-isotope labeling procedure. Infected cells were incubated for two hours with 14C-labeled amino acids, pulse-labeled with [3H]leucine and incubated for various times with an excess of non-radioactive leucine. The ratio was determined for each viral polypeptide in isolated plasma membranes and in the whole cell by polyacrylamide gel electrophoresis. It was found that [3H]leucine-labeled viral polypeptides could be detected in the plasma membranes immediately following a 30-second pulse but that the ratios of polypeptides in the plasma membrane did not reach the ratios in the whole cells until the end of a two-minute chase period. The addition of puromycin to the cultures at the end of the pulse period did not affect subsequent incorporation of [3H]leucine-labeled polypeptides into the plasma membrane. The incorporation of various amino acid analogs into the viral polypeptides did not affect the efficiency with which they were incorporated into the plasma membranes. It is proposed that viral polypeptides are selected for incorporation into the plasma membrane from a small interior pool of completed molecules. 相似文献
11.
Indentification of two somatomedin A active polypeptides and in vivo effects of a somatomedin A concentrate 总被引:5,自引:0,他引:5
L Fryklund K Uthne H Sievertsson 《Biochemical and biophysical research communications》1974,61(3):957-962
The first chemical characterization of two polypeptides from human serum which stimulate the incorporation of 35S sulfate into chick cartilage is described. These two polypeptides, designated Somatomedin A1 and A2 have a molecular weight of approximately 7000. Although each peptide contains 1 cysteine residue and has asparagine as amino terminal residue, there are apparent differences in the amino acid composition. Administration of a Somatomedin A concentrate to hypophysectomized rats gave an increase in tibial width similar to that obtained with 20 μg human growth hormone. 相似文献
12.
DNA-binding proteins of Xenopus laevis: synthesis during oogenesis-ovulation and early embryogenesis
DNA-binding proteins of Xenopus laevis synthesized during two periods of early development (oogenesis-ovulation and early embryogenesis) were co-chromatographed on DNA-cellulose. Proteins with an affinity for DNA were analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Most of the proteins eluted from DNA-cellulose with 0.6 M NaCl had mol. wts less than 40 000; some of these proteins were synthesized to a greater extent by developing embryos than by oocytes. A DNA-binding protein or group of proteins with a mol. wt of approx. 70 000 was synthesized during oogenesis-ovulation but not during embryogenesis. Differential labeling of developing embryos with and indicated that some of the low mol. wt DNA-binding proteins are histones. Some of these proteins also incorporated monosodium . A greater fraction of the proteins synthesized by oocytes and developing embryos were bound to DNA-histone-cellulose than to DNA-cellulose. A group of low mol. wt proteins made during oogenesis-ovulation were bound more to DNA-histone-cellulose than were proteins with similar mol. wts made by developing embryos. 相似文献
13.
A chromatographic procedure utilizing common laboratory equipment and based on the batchwise adsorption of type C RNA virus onto hydroxyapatite for the concentration and partial purification of viruses from large volumes of tissue culture fluid has been developed. This procedure provides an alternative to the use of elaborate and expensive high-speed zonal ultracentrifuge equipment. The viruses obtained by this procedure have a buoyant density of 1.16 g/cm3, contain 70 S RNA, an RNA-directed DNA polymerase (reverse transeriptase), surface glycoproteins (), and the internal viral specific polypeptides p10 to 15 and p27 or p30. 相似文献
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Reactive sulfhydryl and disulfide groups were identified in platelet membrane proteins resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Platelet membranes treated with , phenyl[203Hg]mercuric acetate and showed similar patterns of distribution of sulfhydryl groups among the sodium dodecyl sulfate-solubilized membrane proteins. Four major and two minor polypeptides ranging in molecular weight from > 200 000 to 20 000 were found to have reactive SH groups. Reduction of membrane proteins by sulfite coupled with subsequent mercaptide formation of the resultant monothiols led to the identification of four polypeptides with disulfide bonds. Reaction of platelet membranes with 14C-labeled 5,5′-dithio-bis(2-nitrobenzoic acid) resulted in changes in the distribution profile of the solubilized membrane proteins suggestive of a polymerization process dependent upon 5,5′-dithio-bis(2-nitrobenzoic acid)-induced intermolecular disulfide interchange. 相似文献
16.
Lack of mutagenicity and metabolic inactivation of aphidicolin by rat liver microsomes 总被引:1,自引:0,他引:1
G Pedrali-Noy G Mazza F Focher S Spadari 《Biochemical and biophysical research communications》1980,93(4):1094-1103
In view of the possible utilization of aphidicolin, a specific inhibitor of DNA polymerase α, in the treatment of neoplastic diseases, it seemed important to assess the mutagenic effect of the drug and the possible modification induced by metabolic activation in the liver. This paper shows that aphidicolin lacks mutagenicity in the Ames' -microsome test in agreement with our previous observation that it does not induce DNA repair synthesis in HeLa cells. During the studies of mutagenicity we have observed that aphidicolin is converted to inactive derivative(s) by rat liver microsomal oxidases. The reaction is dependent on time and temperature and requires NADP+ and glucose-6-P. The metabolites are not mutagenic and they do not induce DNA repair synthesis in HeLa cells. Therefore the possible anti-cancer use of aphidicolin is not hampered by its partial metabolic inactivation in liver. Our results suggest however that aphidicolin will possibly be clinically useful at concentrations higher than those expected from our studies with human DNA polymerase and human neoplastic cell lines . The metabolic derivative(s) of aphidicolin is inactive both against cellular DNA polymerase α and Herpes simplex viral DNA polymerase. 相似文献
17.
A class of non-histone chromatin proteins that were bound tightly to DNA and could not be dissociated from the chromatin by high salt and urea was isolated from HeLa cell nuclei and separated from DNA by DNase digestion. These ‘tight’ proteins retained their ability to bind to single- and double-stranded DNA as assayed by nitrocellulose filter binding. Polyacrylamide gel electrophoresis showed that the most prominent proteins possessed molecular weights of about 60 000 D. In asynchronously growing HeLa cell cultures about of the cell nuclei were immunoreactive to fluorescein-labeled antinucleoside antibodies. The immunoreactive cells were the fraction in S phase. Cycloheximide treatment of the cultures raised the fraction of immunoreactive nuclei to over . Exposure of the fixed cycloheximide-treated cell to tight proteins prior to staining with the antibody reduced the fraction of immunoreactive cells to the normal S phase level. Immuno-reactivity induced by X-irradiation or by the intercalating mutagen hycanthone was also suppressed by tight proteins. Cycloheximide treatment preferentially reduced the cellular content of tight proteins, suggesting that these proteins undergo a metabolic turnover with a half-life of about 5 h. 相似文献
18.
R.S. Foote S. Mitra B.C. Pal 《Biochemical and biophysical research communications》1980,97(2):654-659
6-Methyl[8-3H]deoxyguanosine in a synthetic DNA polymer, poly(dC, dG, m6dG), is demethylated by cell-free extracts of adapted by exposure to -methyl-′-nitro--nitrosoguanidine, as shown by the appearance of 3H-labeled deoxyguanosine in hydrolysates of the recovered DNA. The demethylating activity could not be detected in extracts of nonadapted . These results provide direct evidence that a previously described inducible repair activity in acts by demethylating 6-methylguanine at the DNA level. 相似文献
19.
A sensitive immunological technique is described that detects proteins in sodium dodecylsulfate gels of crude cell extracts. The method is based on the binding of 125I-protein A to gels that have been incubated with antibody to a specific protein. Using antibody to the yeast protein, single polypeptides can be detected in mutant and wild-type extracts. The size of these polypeptides correlates both with the type of mutation and with its location in the region. 相似文献
20.
Identification of the structural gene for yeast cytochrome c oxidase subunit I on mitochondrial DNA.
E Keyhani 《Biochemical and biophysical research communications》1979,89(4):1212-1216
Mitochondrial protein synthesis was analyzed in the yeast mit? mutants of which specifically lack cytochrome oxidase. [3H]leucine labeled polypeptides synthesized in yeast OXI 3 mutant were analyzed by means of immunoprecipitation and SDS-polyacrylamide gel electrophoresis (SDS-PAGE). When compared to control, subunit I was not detectable. This result was substantiated by growing OXI 3 mutant in the presence of cycloheximide, an inhibitor of cytoplasmic protein synthesis. Under such conditions SDS-PAGE analysis of [3H]leucine labeled immunoprecipitate shows the absence of subunit I. These data show that the OXI 3 locus contains the structural gene for cytochrome oxidase subunit I. 相似文献