Physicochemical properties of Nebraska calf diarrhea virus hemagglutinin

1978 ◽  
Vol 24 (11) ◽  
pp. 1425-1430 ◽  
Author(s):  
F. R. Bishai ◽  
P. Blaskovic ◽  
D. Goodwin
Keyword(s):  
Physicochemical Properties ◽  
Ethyl Alcohol ◽  
Methyl Alcohol ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Cesium Chloride ◽  
Effect Of Temperature ◽  
Diarrhea Virus ◽  
Calf Diarrhea ◽  
Virus Morphology

Highly purified Nebraska calf diarrhea virus (NCDV)was prepared by cesium chloride density gradient centrifugation. The effect of temperature, pH, different concentrations of formaldehyde, chloroform, ether, ethyl alcohol, and methyl alcohol on NCDV hemagglutinin and virus morphology was studied. NCDV hemagglutinin was inactivated by temperature, pH 2.0, chloroform, ethyl alcohol, and methyl alcohol.

Subcellular localization of oxytocin in the ovine corpus luteum

1985 ◽  
Vol 63 (4) ◽  
pp. 309-314 ◽  
Author(s):  
G. E. Rice ◽  
G. D. Thorburn
Keyword(s):  
Subcellular Localization ◽  
Physicochemical Properties ◽  
Corpus Luteum ◽  
Density Gradient Centrifugation ◽  
Secretory Granules ◽  
Gradient Centrifugation ◽  
Particulate Fraction ◽  
Dense Granules ◽  
Oxytocin Release ◽  
Midluteal Phase

The subcellular localization of oxytocin within the corpus luteum of sheep was investigated using differential and density gradient centrifugation. Oxytocin was associated with a particulate fraction which sedimented to a density of 1.054 – 1.061 g/mL. The exclusion of [3H]oxytocin from this particulate fraction is indicative that particulate oxytocin represents endogenous compartmentalization. Particulate oxytocin, incubated in buffered medium at 37 °C, was stable for up to 1 h and the release of oxytocin was not affected by the pH of the incubation medium, over the range 5.5 – 8.5. Oxytocin release, however, was stimulated by incubating particle-bound oxytocin in buffered medium of low osmolality (<200 mosmol). These data are similar to the physicochemical properties reported for peptide-containing neurohypophysial secretory granules. Ultrastructural analysis of oxytocin-containing fractions revealed the presence of electron-dense granules (diameter, 200–250 nm). These data are suggestive that oxytocin, in the corpus luteum of sheep, is contained within a population of secretory granules which occur in high numbers during the midluteal phase of the oestrous cycle.

PSEUDOMONAS AERUGINOSA BACTERIOPHAGE SD1

1966 ◽  
Vol 12 (5) ◽  
pp. 885-893 ◽  
Author(s):  
P. D. Shargool ◽  
E. E. Townsend
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Thermal Denaturation ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Cesium Chloride ◽  
Defined Medium ◽  
Differential Centrifugation ◽  
Ordered Structure ◽  
Base Analysis ◽  
Denaturation Profile

A DNA-containing bacteriophage, designated SD1, was isolated from sewage, using strain B71 of Pseudomonas aeruginosa as host. Lysates titering 1 to 2 × 1011plaque-forming units/ml are produced by infecting cultures growing in a defined medium. Highly purified phage preparations were obtained by a procedure involving concentration with ammonium sulfate at pH 8.2, differential centrifugation, and density gradient centrifugation in cesium chloride solution.Electron microscopy revealed a structure possessing a head of regular hexagonal outline, 50 mμ in diameter, and a tail, 6.2 × 188 mμ. The phage contained approximately 2.8 × 10−17 g nitrogen, 8 × 10−18 g of phosphorus, and 1.1 × 10−16 g DNA per plaque-forming unit. Base analysis of SD1 DNA disclosed the presence of equimolar amounts of adenine and thymine and of guanine and cytosine; the latter two comprise 53% of the bases. The thermal denaturation profile of the isolated DNA indicates that SD1 DNA is a highly ordered structure: the guanine and cytosine content as estimated from the temperature of half maximal ultraviolet absorption agrees with that found by chemical analysis of the DNA.

scholarly journals Absence of DNA in peroxisomes of Candida tropicalis

1982 ◽  
Vol 152 (1) ◽  
pp. 269-274
Author(s):  
T Kamiryo ◽  
M Abe ◽  
K Okazaki ◽  
S Kato ◽  
N Shimamoto
Keyword(s):  
Mitochondrial Dna ◽  
Oleic Acid ◽  
Candida Tropicalis ◽  
Sodium Sulfite ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Cesium Chloride ◽  
Purification Procedure ◽  
Restriction Fragments ◽  
Low Ionic Strength

Yeast peroxisomes were purified to near homogeneity from cells of Candida tropicalis grown on oleic acid for the purpose of examining the possible presence of DNA in this organelle. The purification procedure includes the effective conversion of cells to spheroplasts with Zymolyase and sodium sulfite and the separation of the organelles at extremely low ionic strength. The mitochondrial contamination was less than 1%, based on several criteria, and the yield of peroxisomes was about 40%. The purified peroxisomal fraction contained a very small amount of DNA, which yielded restriction fragments indistinguishable from those of mitochondrial DNA. The absence of DNA in peroxisomes was also supported by cesium chloride density gradient centrifugation of the organelles lysed with a detergent, staining of the organelles with a fluorescent dye specific to DNA, and labeling of the DNA with [3H]adenine.

Studies on the Cytotoxicity of Myleran and Dimethyl Myleran

1972 ◽  
Vol 50 (10) ◽  
pp. 1074-1081 ◽  
Author(s):  
M. P. Mitchell ◽  
I. G. Walker
Keyword(s):  
Density Gradient ◽  
Density Gradient Centrifugation ◽  
Alkylating Agents ◽  
Gradient Centrifugation ◽  
Cesium Chloride ◽  
Cross Linking ◽  
Alkaline Denaturation ◽  
Dna Strands ◽  
Cross Links

Myleran and dimethyl Myleran (DMM) are two potentially bifunctional alkylating agents which might be expected to form cross-links between guanine residues on the same or opposite strands of native DNA. When L cells were treated with these agents DMM was considerably more toxic than Myleran. When DNA, RNA, and protein were subsequently isolated and analyzed it was found that both agents reacted with DNA to the same extent, the degree of labelling being linear with the concentration of the agents. RNA and protein were labelled to a rather greater extent. When DNA was analyzed chromatographically, no evidence was found for the formation of alkylated guanine residues after treatment with DMM. With Myleran, a product corresponding to the N-7 alkylated monoguaninyl derivative was formed, but no diguaninyl product was detected. Similar results were obtained when DNA was treated in vitro. No evidence of cross-linking by either agent was found when DNA treated in vitro was subjected to alkaline denaturation and subsequent renaturation, and then analyzed by cesium chloride density gradient centrifugation. It is concluded that neither Myleran nor DMM causes cross-linking of DNA strands, nor do they form links between adjacent guanine residues in one strand of DNA.

scholarly journals On the Nature of Recombinants Formed during Transformation in Hemophilus influenzae

1966 ◽  
Vol 49 (6) ◽  
pp. 197-209 ◽  
Author(s):  
Nihal Notani ◽  
Sol H. Goodgal
Keyword(s):  
Recombinant Dna ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Cesium Chloride ◽  
Transformation Process ◽  
Dna Evidence ◽  
Hemophilus Influenzae ◽  
Covalently Linked ◽  
Original Donor ◽  
Hybrid Dna

During the process of transformation in Hemophilus influenzae integration of donor DNA, i.e. the formation of recombinant DNA, involves the incorporation of single-stranded DNA. Evidence was obtained from cesium chloride density gradient centrifugation of DNA from donor-recipient complexes that integration was accompanied by the formation of hybrid DNA with a density intermediate with respect to heavy, 2H, 15N, donor and light, 1H, 4N recipient DNA. On denaturation the position of the heavy donor DNA moved closer to, but not all the way toward, the density position of the original donor DNA. In addition to supporting the idea of single-stranded incorporation, this evidence suggested that the integrated donor DNA was covalently linked to light recipient DNA. The DNA was taken up in the double-stranded form and no detectable amounts of denatured DNA could be found during the transformation process. However, during the process of integration an amount of donor atoms, equivalent to the amount of hybrid DNA formed, appeared in recipient DNA, and indicated that while one strand of DNA was integrated the other was broken down and resynthesized. The density of the hybrid DNA, as well as rebanding of denatured hybrid, indicated that the size of the integrated piece of DNA was large, approximately 6 x 106 daltons.

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