Ribonucleic acids of differentiating and non-differentiating uredosporelings of wheat stem rust

1974 ◽  
Vol 52 (6) ◽  
pp. 1309-1317 ◽  
Author(s):  
W. K. Kim ◽  
R. Rohringer
Keyword(s):  
Ribosomal Rna ◽  
Stem Rust ◽  
Gel Electrophoresis ◽  
Gradient Centrifugation ◽  
Sucrose Density Gradient ◽  
Wheat Stem Rust ◽  
Sucrose Density Gradient Centrifugation ◽  
Ribonucleic Acids ◽  
Molecular Weights ◽  
Germ Tubes

Uredospores of wheat stem rust (Puccinia graminis Pers. f. sp. tritici Eriks. & E. Henn.) were deposited onto Millipore membranes and allowed to germinate. Those remaining continuously at 20° formed germ tubes only (non-differentiated), but those exposed to 30° for 90 min after the first 2 h of germination developed infection structures corresponding to appressoria and substomatal vesicles (differentiated).Nucleic acids were extracted with a phenol method from resting uredospores and from differentiated and non-differentiated sporelings. The amount of extractable RNA decreased as germination progressed, but no RNA was detected in the germination medium. The decrease in extractable RNA (up to 40%) occurred in both differentiated and non-differentiated sporelings.Acrylamide gel electrophoresis was used to separate RNA species and to determine their approximate molecular weights (in daltons): sporelings contained 25-S (1.65 × 106) and 18-S (0.80 × 106) ribosomal RNA (rRNA), 5-S (3.6 × 104) rRNA, and 4.5-S (2.4 × 104) transfer RNA (tRNA). Radioactive uridine, fed to sporelings, was incorporated mostly into 5-S rRNA and (or) tRNA.Acrylamide gel electrophoresis and sucrose density gradient centrifugation revealed that differentiated sporelings contained a type of RNA that was not detected in non-differentiated sporelings. It was heterogeneous and migrated in the 16-S to 5-S interval on polyacrylamide gels. Some of the RNA present in this fraction may have been preformed in resting spores and released from more complex material during the process of differentiation.

THE TERMINAL GROUPS OF RIBONUCLEATE CHAINS IN EACH OF THE 16S AND 23S COMPONENTS OF ESCHERICHIA COLI RIBOSOMAL RNA

1967 ◽  
Vol 45 (6) ◽  
pp. 937-948 ◽  
Author(s):  
J. L. Nichols ◽  
B. G. Lane
Keyword(s):  
Escherichia Coli ◽  
Chain Length ◽  
Ribosomal Rna ◽  
Gradient Centrifugation ◽  
Sucrose Density Gradient ◽  
Sucrose Density Gradient Centrifugation ◽  
Quantitative Estimates ◽  
16S Rna ◽  
The Mean ◽  
End Group

Ribosomal ribonucleates from Escherichia coli have been resolved into 16S and 28S components by sucrose density-gradient centrifugation, and the chain termini in each of the 16S and 23S RNA components have been analyzed by hydrolysis with alkali. The principal 5′-linked end group of 16S RNA was found to be adenosine, and the principal 5′-linked end group of 23S RNA was found to be uridine. The principal 3′-linked end group of 16S RNA was also found to be adenosine, whereas the principal 3′-linked end group of 23S RNA was found to be guanosine. Quantitative estimates of chain length based on analyses for 5′-iinked terminals indicate that the mean chain length for 16S RNA is about 1.3 × 103nucleotide residues and the mean chain length for 23S RNA is about 2.1 × 103nucleotide residues.

scholarly journals Purification of the constituent enzyme fractions of mycobacillin synthetase

1986 ◽  
Vol 235 (1) ◽  
pp. 81-85 ◽  
Author(s):  
S K Ghosh ◽  
N K Mukhopadhyay ◽  
S Majumder ◽  
S K Bose
Keyword(s):  
Gel Electrophoresis ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Sucrose Density Gradient ◽  
Polyacrylamide Gel ◽  
Subunit Structure ◽  
Sucrose Density Gradient Centrifugation ◽  
Final Purification

The final purification of the three-fraction enzyme complex mycobacillin synthetase was done by hydroxyapatite column chromatography and sucrose-density-gradient centrifugation; each of the fractions obtained migrates as a single component in SDS/polyacrylamide-gel electrophoresis and gel electrofocusing. The Mr of the enzyme fractions A, B and C by gel filtration is 260 000, 190 000 and 105 000, and that by SDS/polyacrylamide-gel electrophoresis is 252 000, 198 000 and 108 000 respectively. None of the enzyme fractions appears to possess subunit structure.

scholarly journals Evidence of low molecular weight RNAs involved in permanent character changes in amoebae

1980 ◽  
Vol 43 (1) ◽  
pp. 329-340
Author(s):  
S.E. Hawkins
Keyword(s):  
Microsomal Fraction ◽  
Gradient Centrifugation ◽  
Polyacrylamide Gel Electrophoresis ◽  
Active Material ◽  
Sucrose Density Gradient ◽  
Low Molecular Weight ◽  
Sucrose Density Gradient Centrifugation ◽  
Rna Molecules ◽  
Molecular Weights ◽  
Lowered Sensitivity

Previous studies have established that ‘informational molecules’ present in cytoplasmic fractions of A. discoides may be transferred by microinjection into A. proteus. Clones derived from injected cells showed various changers, including lowered sensitivity to growth in streptomycin and neomycin, in which respects they resembled A. discoides. These changes in response to antibiotics were transferred independently and were permanent, the information being replicated over many generations. The most ‘active’ material in terms of the number of clones showing character changes was found following injection of 16S ribonucleoprotein obtained after sucrose density gradient centrifugation of the mcirosomal fraction. Polyacrylamide gel electrophoresis of the 16S material showed 3 small peaks of RNA. In order to obtain adequate amounts of material, these peaks of RNA were identified in electrophoresis profiles of RNA extracted from the whole microsomal fraction, and RNA eluted from these latter gels was injected into A. proteus. Although the number of surviving clones was low, all were examined for their response to growth in either streptomycin, neomycin, erythromycin or chloroquine. After injection of RNA eluted from the 3 small peaks of RNA (slices 26–33), 8 out of 10 and 9 out of 10 clones showed lowered sensitivity to growth in streptomycin and neomycin respectively, and resembled the donor A. discoides. No changes in responses to antibiotics were obtained from clones derived from cells injected with RNA eluted from another region of the gel, or after ribonuclease treatment of the RNA from slices 26–33. The relative molecular weights of these ‘informational’ RNA molecules were found to be between 9 and 13 X 10(4) Daltons.

Nucleoli in differentiated germ tubes of wheat rust uredospores

1970 ◽  
Vol 48 (9) ◽  
pp. 1693-1695 ◽  
Author(s):  
Larry D. Dunkle ◽  
William P. Wergin ◽  
Paul J. Allen
Keyword(s):  
Electron Microscopy ◽  
Heat Shock ◽  
Nuclear Envelope ◽  
Outer Membrane ◽  
Ribosomal Rna ◽  
Stem Rust ◽  
Wheat Stem Rust ◽  
Cytoplasmic Structures ◽  
Germ Tubes ◽  
Wheat Rust

Nucleoli observed by electron microscopy are illustrated in germ tubes of wheat stem rust uredospores which have been induced by heat shock to differentiate infection structures. The presence of nucleoli in these structures suggests that this obligate parasite may possess the capacity of synthesizing ribosomal RNA independently of its host. In addition to nucleoli, heterochromatin is characteristically observed appressed to the inner membrane of the nuclear envelope. This material is associated with distinct cytoplasmic structures which are appressed to the outer membrane of the nuclear envelope and resemble developing centrioles in other fungi.

A malate dehydrogenase of high molecular weight, from bean leaves

1968 ◽  
Vol 46 (5) ◽  
pp. 719-720 ◽  
Author(s):  
William Habig ◽  
David Racusen
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Malate Dehydrogenase ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Sucrose Density Gradient ◽  
Sucrose Density Gradient Centrifugation ◽  
Molecular Weights ◽  
Young Leaves ◽  
Bean Leaves

Two forms of malate dehydrogenase (MDH) of widely differing molecular weight were found in primary leaves of Phaseolus vulgaris. Their molecular weights were estimated as 69 000 and 275 000 by sucrose density gradient centrifugation. The ratio of these two forms followed an orderly course in which the high molecular weight MDH increased from near zero in very young leaves to about 35% of the total MDH activity in leaves older than 2 weeks. Conditions which cause the high molecular weight MDH to dissociate to active normal molecular weight enzyme are discussed.

scholarly journals Chymotryptic digestion of Tetrahymena 22S dynein. I. Decomposition of three-headed 22S dynein to one- and two-headed particles.

1987 ◽  
Vol 105 (2) ◽  
pp. 887-895 ◽  
Author(s):  
Y Y Toyoshima
Keyword(s):  
Electron Microscopy ◽  
Gel Electrophoresis ◽  
Gradient Centrifugation ◽  
Sedimentation Coefficient ◽  
Sucrose Density Gradient ◽  
Sucrose Density Gradient Centrifugation ◽  
Heavy Chains ◽  
Time Courses ◽  
The One ◽  
Dynein Heavy Chains

Molecular composition of Tetrahymena ciliary dynein has been examined by electron microscopy and gel electrophoresis. SDS-urea gel electrophoresis revealed that Tetrahymena 22S dynein contains three (A alpha, A beta, and A gamma) heavy chains whereas 14S dynein contains only one. The molecular masses of 22S and 14S dynein heavy chains were estimated to be approximately 490 and 460 kD, respectively. Electron microscopy of negatively stained specimens showed 22S dynein has three globular heads and thin stalks, whereas 14S dynein consists of a single head. Chymotrypsin digested each of the three 22S dynein heavy chains into large fragments with different time courses. Sucrose density gradient centrifugation separated the digestion products as two peaks. The one with a larger sedimentation coefficient mainly consisted of two-headed particles having binding ability to doublet microtubules, whereas the other with a smaller sedimentation coefficient consisted of only isolated globular particles. Both fractions had ATPase activities. Thus, one active head of 22S dynein can be isolated by chymotrypsin digestion.

The Combining Ability of Glycoproteins IIb, IIIa and Ca2+ in EDTA-Treated Nonaggregable Platelets

1983 ◽  
Vol 50 (04) ◽  
pp. 848-851 ◽  
Author(s):  
Marjorie B Zucker ◽  
David Varon ◽  
Nicholas C Masiello ◽  
Simon Karpatkin
Keyword(s):  
Density Gradient ◽  
Combining Ability ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Electrophoretic Pattern ◽  
Sucrose Density Gradient ◽  
Irreversible Loss ◽  
Sucrose Density Gradient Centrifugation ◽  
Crossed Immunoelectrophoresis ◽  
Triton X

SummaryPlatelets deprived of calcium and incubated at 37° C for 10 min lose their ability to bind fibrinogen or aggregate with ADP when adequate concentrations of calcium are restored. Since the calcium complex of glycoproteins (GP) IIb and IIIa is the presumed receptor for fibrinogen, it seemed appropriate to examine the behavior of these glycoproteins in incubated non-aggregable platelets. No differences were noted in the electrophoretic pattern of nonaggregable EDTA-treated and aggregable control CaEDTA-treated platelets when SDS gels of Triton X- 114 fractions were stained with silver. GP IIb and IIIa were extracted from either nonaggregable EDTA-treated platelets or aggregable control platelets with calcium-Tris-Triton buffer and subjected to sucrose density gradient centrifugation or crossed immunoelectrophoresis. With both types of platelets, these glycoproteins formed a complex in the presence of calcium. If the glycoproteins were extracted with EDTA-Tris-Triton buffer, or if Triton-solubilized platelet membranes were incubated with EGTA at 37° C for 30 min, GP IIb and IIIa were unable to form a complex in the presence of calcium. We conclude that inability of extracted GP IIb and IIIa to combine in the presence of calcium is not responsible for the irreversible loss of aggregability that occurs when whole platelets are incubated with EDTA at 37° C.

scholarly journals Molecular heterogeneity of mouse duodenal alkaline phosphatase. Association of lipids and peptides

1974 ◽  
Vol 141 (1) ◽  
pp. 93-101 ◽  
Author(s):  
P. R. V. Nayudu ◽  
Fraser B. Hercus
Keyword(s):  
Alkaline Phosphatase ◽  
Gradient Centrifugation ◽  
Polyacrylamide Gel Electrophoresis ◽  
Buoyant Density ◽  
Sucrose Density Gradient ◽  
Molar Ratio ◽  
Molecular Forms ◽  
Partial Specific Volume ◽  
Molecular Heterogeneity ◽  
Sucrose Density Gradient Centrifugation

Polyacrylamide-gel electrophoresis and Bio-Gel P-300 molecular-sieve chromatography of mouse duodenal alkaline phosphatase demonstrates its molecular heterogeneity, which, in a kinetic sense, is manifest also in the differential relative velocities of the heterogeneous forms of the enzyme with two substrates, phenylphosphate and β-glycerophosphate. Different treatments that eliminate most of the electrophoretic and chromatographic variability of the enzyme also decrease the velocities with both substrates so that the molar ratio of hydrolysis of one substrate relative to the other is also altered to a low but stable value. Concomitant with these changes, lipids and peptides are dissociated from the enzyme. The lipids are tentatively identified as a sterol and phospholipids. The peptides have an average composition of four to six amino acids and appear to be strongly electropositive. The conditions of dissociation suggest that their binding to the enzyme is non-covalent and predominantly based on hydrophobic and ionic bonding. The concept of lipid and peptide association would suggest prima facie differential molecular weights as a factor in the observed electrophoretic and chromatographic heterogeneity. However, the molecular forms of the enzyme with differences in elution volume equivalent to more than one-half the void volume of the Bio-Gel P-300 column, or even enzyme fractions dissociated from the lipids and peptides compared with undissociated portions, do not show any differences in sedimentation on sucrose-density-gradient centrifugation. This may be because the alterations in molecular weight owing to binding of small molecules are too small to be detected by this method. Alternatively, since lipids are involved, the binding may alter the partial specific volume in such a way that the buoyant density is not significantly altered.

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