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1.
A T Tu B Prescott C H Chou G J Thomas 《Biochemical and biophysical research communications》1976,68(4):1139-1145
Laser Raman Spectra were obtained on aqueous and solid samples of Mojave toxin isolated from the venom of the Mojave rattlesnake (). The Raman spectra reveal that the Mojave toxin, an acidic protein of molecular weight about 22,000, contains a predominantly α-helical secondary structure and that the tyrosyl residues, on the basis of the Raman frequencies and intensities, are exposed to the solvent. These features of the Mojave toxin distinguish it structurally from the neurotoxins of sea snake venoms. However, like the sea snake venom toxins, Mojave toxin contains four disulfide bridges and is not greatly altered in structure by removal of the aqueous solvent. 相似文献
2.
D.A. Stringfellow C.M. Scanlan R.R. Brown G.B. Meadows B.W. Gray R.R. Young-White 《Theriogenology》1984,21(6):1005-1012
Fifty-four day-6 through day-10 (estrus=day 0) embryos were collected nonsurgically from 13 superovulated, brucellosis-free mixed breed cows. Forty-eight excellent and good zona pellucida-intact (ZP-I), three zona pellucida-defective (ZP-D), and three zona pellucida-free (ZP-F) embryos were incubated in media containing . Subsequently, embryos were washed ten times in groups of one, two, three, or four. Embryos and serial washes were cultured for . .Brucellae were not isolated from any ZP-I embryo or from any washing beyond the sixth serial wash. Brucellae were not isolated from the three ZP-F embryos but were detected in the eighth wash for one and in the tenth wash for the others. Brucellae were isolated from one of three ZP-D embryos. Results show that ZP-I embryos can be effectively washed free of . . 相似文献
3.
Hemolytically active fractions were isolated from the toxins produced by the red-tide dinoflagellate (GBTX) and the chrysomonad (PPTX). High pressure liquid chromatography through bonded phase (ODS) silica columns using a gradient of methanol in chloroform yielded 6 major fractions from GBTX, 3 of which were hemolytic (HD50=0.3?0.56 μg·ml?1). None were ichthyotoxic. Of the 6 fractions obtained from PPTX, 4 were hemolytic (HD50=0.013?2.8 μg·ml?1) but only one (fraction 6) was ichthyotoxic. This fraction was ~ 2000 times more hemolytic than the crude PPTX (HD50=33.2 μg·ml?1). Analysis of their UV spectra indicates that the fractions within each group are closely related. 相似文献
4.
Mycoplasma was isolated from the genital tracts of 8 of 96 culled dairy cows. Procedures were used to reduce the possibility of uterine contamination by vaginal fluids. The mycoplasma isolates were identified by the fluorescent antibody technique as: (4), (1), an untyped bovine pathogen from the mammary gland designed as ST-6 (2), and an isolate that could not be identified with the labeled antibodies used in this study. All isolations were made from vaginal swabs, except in one case of pyometra where was isolated concurrently from the uterus and vagina, along with . These results suggest that mycoplasma may be found in the cervico-vaginal flora of some cattle but are rarely isolated from the uterine environment. 相似文献
5.
U E Brady 《Life sciences》1973,13(3):227-235
-9-tetradecen-l-ol acetate was isolated from both extracts of female abdominal tips and of filter paper exposed to female (Walker). It is the second sex stimulant isolated from this species and, in stimulatory bioassays, it is ca. 1/100, 000 as active as the stimulant isolated previously, -9, -12-tetradecadien-l-ol acetate. According to attractancy tests, the natural sex pheromone system of complex contains other components in addition to these 2 stimulants. 相似文献
6.
Activation of the template activity of isolated rat liver nuclei for DNA synthesis and its inhibition by NAD 总被引:6,自引:0,他引:6
The template activity of isolated rat liver nuclei for DNA synthesis assayed with DNA polymerase was found to be dependent upon the presence of Ca2+ or Mg2+ in the incubation medium. DNA was prepared from isolated nuclei subjected to conditions which activated the template and centrifuged in an alkaline sucrose gradient. The distribution profile showed that smaller fragments were formed, suggesting enhancement of endonucleolytic activity. When isolated nuclei were incubated with NAD to induce poly(adenosine diphosphate ribose) formation and were subjected to the activation conditions, the template for DNA synthesis remained unchanged. The distribution profile in an alkaline sucrose gradient of DNA prepared from these nuclei and control nuclei was identical. The present findings suggest that the template-activating system for DNA synthesis was blocked when isolated nuclei were treated with NAD . 相似文献
7.
Altered restriction of nuclear RNA during incubation in vitro 总被引:1,自引:0,他引:1
Nuclei were isolated from rat liver and incubated in two commonly employed RNA transport assays. Released [14C] RNA was isolated and hybridized with filter-bound DNA in the presence of competing cytoplasmic RNA. A significant portion of RNA which was transported to either medium was not represented in cytoplasmic RNA. These results indicate that the restriction of some sequences to the nucleus is not maintained . 相似文献
8.
Taiji Nakae 《Biochemical and biophysical research communications》1976,71(3):877-884
Outer membrane of allows a rapid diffusion of saccharides of molecular weights less than 550. This permeability property could be restored in vesicle membranes reconstituted from isolated phospholipids, lipopolysaccharide, and an outer membrane protein. The active protein aggregates were isolated from the insoluble material left after solubilization of cell envelope of B with sodium dodecyl sulfate at 35°. Analysis by acrylamide gel electrophoresis, isoelectric focusing and amino terminal amino acid determination revealed that only a single species of protein, with a molecular weight of 36,500 forms the oligoprotein aggregates which produces diffusion channels. 相似文献
9.
Membrane vesicles from Escherichia coli wild type and an otherwise isogenic mutant were used to immunize rabbits. In addition, a membrane protein fraction, containing the material found deficient in A mutants, was purified by preparative polyacrylamide gel electrophoresis in sodium dodecylsulfate, and used for immunization. The antisera produced were analyzed by immunoelectrophoresis and immunofluorescence microscopy. The antisera obtained by immunization with membrane vesicles from either wild type or mutant membrane preparations were qualitatively similar in the precipitin bands seen after immunoelectrophoresis. The antisera obtained by immunization with the purified protein fraction contained a subset of the antibodies seen when whole vesicles were used for immunization. In a semiquantitative precipitin assay, the antisera prepared against whole membrane vesicles or the isolated protein fraction both caused the precipitation of more protein from sodium dodecylsulfate-solubilized membranes of wild type than of mutants. No difference was seen by immunoelectrophoresis between the protein composition of wild type or membrane preparations. Thus, the mutant appears to differ from the wild type in the quantitative composition of its membrane proteins, whereas no qualitative differences were detected.Fluorescein-conjugated antiserum preparations were employed to assess the reactivity of intact cells, spheroplasts and membrane vesicles with the antisera studied above. Wild type cells of E. coli have a barrier to reaction with the antisera; this barrier is removed when the cells are converted to spheroplasts or to membrane vesicle. Similarly, a highly permeable mutant of E. coli permits reaction of the antisera with unaltered cells. Antisera to both whole membrane vesicles and to the isolated protein fraction react identically with the cellular and subcellular preparations. Thus, antisera prepared from membrane proteins isolated after sodium dodecylsulfate-polyacrylamide gel electrophoresis can still recognize some antigens present in membrane vesicle preparations. 相似文献
10.
Two compounds were isolated from female (Lepidoptera: Noctuidae) extracts and identified as -9-tetradecenal and -ll-hexadecenal. Together they elicit intense male . response in laboratory tests and have attracted males in the field. Although -ll-hexadecenal is an . sex pheromone, no evidence was obtained for -9-tetradecenal in . . 相似文献
11.
Aftab A. Ansari Masroor A. Baig Heinrich V. Malling 《Biochemical and biophysical research communications》1981,102(1):93-99
Lactate dehydrogenase-C (LDH-C) mRNA was purified from mouse testes and translated . First, the LDH-C synthesizing polysomes were isolated by double immunoprecipitation using specific anti-LDH-C and anti-horse immunoglobulin antibodies. Extraction of mRNA was made from the isolated polysomes using hot sodium dodecyl sulfate-phenol method at alkaline pH. In a wheat germ cell-free translation system, the mRNA coded for a polypeptide chain that could be immunoprecipitated with specific anti LDH-C antibody and comigrated with authentic LDH-C in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. 相似文献
12.
Several populations of Prosopis reptans collected along the Texas Gulf coast were examined for their flavonoids and leaf morphology. Seventeen flavonoids were detected and the nine major ones were isolated and identified: apigenin 6- and , luteolin and its , quercetin and its , and myricetin, its and . The presence of a single chemical race was established, since all specimens from the Texas Gulf coast populations were uniform in their chemistry and leaf morphology, and chemically identical to the plant material from Argentina. However, the Argentina material exhibited slight morphological differences in that the leaves possessed less pubescence than the Texas Gulf coast plants. 相似文献
13.
Ken F. Jarrell Andrew M. Kropinski 《Biochemical and biophysical research communications》1981,99(4):1185-1190
Lipopolysaccharides (LPS) isolated from various rough derivatives of strains were found to neutralize coliphage T7. Concentrations of 0.4 – 17 μg LPS/ml were sufficient for 50% inactivation of T7 within 1 hour. From the LPS analyses of the mutants, it is believed that T7 may be binding to the heptose region of LPS, suggesting a similarity in structure between the heptose regions of and LPS. 相似文献
14.
DNA replication in Physarum polycephalum: characterization of replication products made in isolated nuclei 总被引:1,自引:0,他引:1
Nuclei isolated from synchronous S-phase plasmodia of the myxomycete were competent in production of low molecular weight DNA replication intermediates. Furthermore, these nuclei showed some competence in joining these fragments into DNA of intermediate molecular weight. The DNA molecules made could be correlated with products made . 相似文献
15.
William G. Carter Sen-itiroh Hakomori 《Biochemical and biophysical research communications》1977,76(2):299-308
The cell surface glycoproteins of hamster NIL cells, labeled with galactose oxidase and NaB3H4, were selectively solubilized by sequential extraction with Tris buffer containing 1) sucrose-ATP-EDTA, 2) zwitterionic detergent (Empigen BB), and 3) 8 M urea. The previously reported “galactoprotein b” and “galactoprotein a” ( or LETS) were isolated by affinity chromatography on insoluble Ricinus communis lectin colums (RCA column) from extracts 2) and 3), respectively. The affinity-purified contained an actin-like protein, whereas the other affinity-purified galactoproteins did not contain the actin-like protein. The isolated was heterogeneous, and an additional glycoprotein, specific for NILpy cells was copurified on RCA-column with . 相似文献
16.
C H Letendre P C MacDonnell G Guroff 《Biochemical and biophysical research communications》1976,76(2):615-617
Determination of the complete amino acid sequence of the rubredoxin isolated from the sulfate reducing bacterium showed that the molecule consists of a single polypeptide chain of 52 residues. The sequence of the first 42 residues was determined using an automatic Protein Sequencer. Peptides derived from tryptic hydrolysis and from specific cleavage at tryptophan residue were used to construct the total sequence. Compared with the sequence of rubredoxin, 37 positions are identical, and with the sequences of , , and rubredoxins, 20 matching residues occur. A crystallographic study of the rubredoxin is in progress. 相似文献
17.
Two cytochrome proteins were isolated from succinate-cytochrome reductase and the cytochrome complex. Their molecular weights were determined to be 37,000 and 17,000 daltons by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. Spectral properties and amino acid composition of these two proteins are reported in the paper. 相似文献
18.
Evidence for plastoquinol-cytochrome f/b-563 reductase as a common electron donor to P700 and cytochrome oxidase in cyanobacteria 总被引:6,自引:0,他引:6
G A Peschek G Schmetterer 《Biochemical and biophysical research communications》1982,108(3):1188-1195
Membranes isolated from sp. strain MAC and displayed spectral changes in the cytochrome region when examined by reduced oxidized or dual wavelength spectrophotometry under physiological conditions. The same changes accompanied both light-induced (photosynthetic) and oxygen-induced (respiratory) electron transport. Physiological reduction of the cytochrome moiety was abolished after extraction of plastoquinone but reappeared on reconstitution of the depleted membranes with authentic plastoquinone. Moreover, a mutual inhibition of photosynthetic and respiratory activities could be directly demonstrated with the isolated membranes. From the results it is concluded that the membrane-bound plastoquinol-cytochrome reductase functions as a common electron donor to both P700 and the cytochrome oxidase in cyanobacteria. 相似文献
19.
20.
C.A. Ruder R.G. Sasser R.J. Williams J.K. Ely R.C. Bull J.E. Butler 《Theriogenology》1981,15(6):573-580
Clinical conditions, which were observed in primiparous Angus and Hereford heifers with postpartum uterine infections are reported. Forty-three of sixty-four cows (67%) had uterine infections. and were the most frequently isolated aerobe and anaerobe, respectively. Twelve of the sixty-four cows (18.8%) had infections that involved these species. Three of these twelve cows were infected only with , two were infected only with , and seven were infected with both organisms. All five of the cows which were infected with either or showed signs of estrus and four of the five cows conceived by 110 days postpartum. The single cow that did not conceive was infected with . Three of the seven cows which were infected with both organisms showed signs of estrus and none of the seven cows conceived by 110 days postpartum. In addition, when only or was isolated from the uterus, cows had either mild or no clinical signs of infection. In contrast, the seven cows which were infected with both organisms had severe clinical signs of infection that included excessive vulvar discharge, uterine abscesses and pelvic adhesions. These observations suggested that a pathogenic synergism between and might have caused the increased severity of postpartum uterine infections, and the subsequent detrimental effect on return to estrus and conception. 相似文献