Comparison of mammalian mitochondrial ribosomal ribonucleic acid from different species

Mitochondrial ribosomal RNA species from mouse L cells, rat liver, rat hepatoma, hamster BHK-21 cells and human KB cells were examined by electrophoresis on polyacrylamide–agarose gels and sedimentation in sucrose density gradients. The SE (electrophoretic mobility) and S values of mitochondrial rRNA of all species were highly dependent on temperature and ionic strength of the medium; the SE values increased and the S values decreased with an increase in temperature at a low ionic strength. At an ionic strength of 0.3 at 23–25°C or an ionic strength of 0.01 at 3–4°C the S and SE values were almost the same being about 16.2–18.0 and 12.3–13.6 for human and mouse mitochondrial rRNA. The molecular weights under these conditions were calculated to be 3.8×105–4.3×105 and 5.9×105–6.8×105, depending on the technique used. At 25°C in buffers of low ionic strength mouse mitochondrial rRNA species had a lower electrophoretic mobility than those of human and hamster. Under these conditions the smaller mitochondrial rRNA species of hamster had a lower electrophoretic mobility than that of human but the larger component had an identical mobility. Mouse and rat mitochondrial rRNA species had identical electrophoretic mobilities. Complex differences between human and mouse mitochondrial rRNA species were observed on sedimentation in sucrose density gradients under various conditions of temperature and ionic strength. Mouse L-cell mitochondrial rRNA was eluted after cytoplasmic rRNA on a column of methylated albumin–kieselguhr.

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Genetically determined polymorphism of the circulating human breast cancer-associated DF3 antigen

Blood ◽

10.1182/blood.v71.2.436.436 ◽

1988 ◽

Vol 71 (2) ◽

pp. 436-440 ◽

Cited By ~ 10

Author(s):

DF Hayes ◽

H Sekine ◽

D Marcus ◽

CA Alper ◽

DW Kufe

Keyword(s):

Breast Cancer ◽

Electrophoretic Mobility ◽

Core Protein ◽

Human Breast ◽

Mobility Patterns ◽

Multiple Alleles ◽

Molecular Weights ◽

The Core ◽

Electrophoretic Mobilities ◽

Genetically Determined

Abstract The murine monoclonal antibody (MAb) DF3 was prepared against a human breast carcinoma. Previous studies have demonstrated that DF3 antigen levels are elevated in plasma of patients with breast cancer. Furthermore, MAb DF3 reacts with circulating glycoproteins of different molecular weights ranging from approximately 300 to 450 kd. The present study demonstrates that plasma DF3 antigen is comprised of at least four moieties with slow (S), intermediate (I), rapid (R) and very rapid (VR) electrophoretic mobilities. The electrophoretic mobility patterns for circulating DF3 antigen differ among individuals. Moreover, DF3 antigen is detectable in urine, and the electrophoretic mobility of the urinary moieties is similar, but not identical, to that in the plasma. Studies in family members suggest that the electrophoretic heterogeneity of plasma DF3 antigen is determined by codominant expression of multiple alleles at a single locus. This locus may code for the core protein of DF3 antigen. These findings thus identify a genetically determined polymorphism of a circulating tumor-associated glycoprotein.

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ISOPYCNIC CENTRIFUGATION OF CHROMATIN IN RENOGRAFIN SOLUTIONS

The Journal of Cell Biology ◽

10.1083/jcb.61.3.780 ◽

1974 ◽

Vol 61 (3) ◽

pp. 780-788 ◽

Cited By ~ 12

Author(s):

R. T. L. Chan ◽

I. E. Scheffler

Keyword(s):

Ionic Strength ◽

Equilibrium Position ◽

Density Gradients ◽

Low Viscosity ◽

Low Ionic Strength ◽

Isopycnic Centrifugation

Solutions of Renografin (30–60%) can be centrifuged to form density gradients in the range from 1.0 g/cm3 to 1.4 g/cm3 or, alternatively, preformed gradients can be made which under appropriate conditions of centrifugation have an indefinite stability. Such solutions have a low viscosity and a relatively low ionic strength. The density of DNA in such solutions is surprisingly low (∼1.14 g/cm3). Crude chromatin can be sedimented to an equilibrium position in such gradients, corresponding to a density of 1.24 g/cm3, or slightly lower, depending on the method of preparation. The complex is shown to contain DNA, RNA, protein, and possibly some lipoprotein. Most of the RNA can be removed with RNase without any significant effect on the density of the chromatin.

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Granulocyte/macrophage-, megakaryocyte-, eosinophil- and erythroid-colony-stimulating factors produced by mouse spleen cells

Biochemical Journal ◽

10.1042/bj1850301 ◽

1980 ◽

Vol 185 (2) ◽

pp. 301-314 ◽

Cited By ~ 84

Author(s):

Antony W. Burgess ◽

Donald Metcalf ◽

Sue H. M. Russell ◽

Nicos A. Nicola

Keyword(s):

Ionic Strength ◽

Isoelectric Focusing ◽

Biological Activities ◽

Gel Filtration ◽

Maximum Activity ◽

Colony Stimulating Factor ◽

Colony Stimulating Factors ◽

Molecular Weights ◽

Low Ionic Strength ◽

Stimulating Factor

The formation of mature haemopoietic cells is controlled by hormones that specifically stimulate the progenitor cells of the granulocyte/macrophage, eosinophil, megakaryocyte and erythroid pathways. PWMSC medium (pokeweed-mitogen-stimulated spleen-cell-conditioned medium) is known to contain the biological activities that control the clonal proliferation of these four progenitor cells in vitro in semi-solid agar cultures. In this study the molecular properties of these biological activities were characterized, and all four colony-stimulating factors appear to be associated with glycoproteins. These factors were precipitated between 50 and 80%-satd. (NH4)2SO4 and could be concentrated by ultrafiltration over a 10000-mol.wt.-cut-off hollow-fibre membrane. Megakaryocyte- and erythroid-colony-stimulating factors were lost when the conditioned medium was dialysed at low ionic strength (<0.03m). Neither asialo- nor sialo-erythropoietin was detectable in concentrated PWMSC medium or in the fractions purified from it by gel filtration on Sephadex G-150. The factors bound to concanavalin A–Sepharose were eluted with α-methyl-d-glucopyranoside (0.10m). Analysis by gel filtration on Sephadex G-150 indicated that the apparent molecular-weight distributions of all colony-stimulating factors were identical (37000). Treatment with neuraminidase did not alter the biological activities of any of these factors, but when the molecular weights were analysed, after neuraminidase treatment, on Sepharose CL-6B in the presence of guanidine hydrochloride (6m) all were eluted with a mol.wt. of 24000. Although the apparent molecular weights of the different factors were identical, charge differences were detectable by isoelectric focusing on thin-layer granulated gels. There appeared to be considerable charge heterogeneity associated with each factor, as all were focused over 2–4 pH units. The maximum activity of the granulocyte/macrophage-colony-stimulating factor on isoelectric focusing was at pH4.8, whereas the maximum activity for the eosinophil-colony-stimulating factor was at pH5.8. The erythroid- and megakaryocyte-colony-stimulating activities were detected in the pH ranges 4.8–5.8 and 4.6–7.1 respectively. Chromatographic differences between the granulocyte/macrophage- and eosinophil-colony-stimulating factors were also detected by hydrophobic chromatography at low ionic strength (0.15m-NaCl) on Cibacron Blue–Sepharose and at high ionic strength [2m-(NH4)2SO4] on phenyl-Sepharose. Eosinophil-colony-stimulating factor bound more strongly than the other factors to both matrices. The megakaryocyte- and erythroid-colony-stimulating activities were always associated with those for granulocytes/macrophages and eosinophils. Preparations highly enriched for eosinophil-colony-stimulating factor were also obtained by DEAE-cellulose chromatography. An overall purification of 100-fold for all of the factors was achieved with the present techniques, and, although differences were observed, only granulocyte/macrophage-stimulating factors and a small proportion of the eosinophil-stimulating factors could be completely separated from the others. Our results are consistent with the existence of separable factors for granulocyte/macrophage and eosinophil stimulation, but the megakaryocyte- and erythroid-stimulating activities were always associated with the granulocyte/macrophage- and eosinophil-stimulating activities. Thus there may be one molecule that is able to stimulate all four colony types or four very similar molecules that are difficult to separate.

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Subunit composition and structure of subcomponent C1q of the first component of human complement

Biochemical Journal ◽

10.1042/bj1550019 ◽

1976 ◽

Vol 155 (1) ◽

pp. 19-23 ◽

Cited By ~ 234

Author(s):

K B M Reid ◽

R R Porter

Keyword(s):

Ionic Strength ◽

Sodium Dodecyl ◽

Gel Filtration ◽

Helical Structure ◽

Guanidinium Chloride ◽

Molecular Weights ◽

Composition And Structure ◽

Covalently Linked ◽

Low Ionic Strength ◽

Expected Position

1. Unreduced human subcomponent C1q was shown by electrophoresis on polyacrylamide gels run in the presence of sodium dodecyl sulphate to be composed of two types of non-covalently linked subunits of apparent mol.wts. 69 000 and 54 000. The ratio of the two subunits was markedly affected by the ionic strength of the applied sample. At a low ionic strength of applied sample, which gave the optimum value for the 54 000-apparent mol.wt. subunit, a ratio of 1.99:1.00 was obtained for the ratio of the 69 000-apparent mol.wt. subunit to the 5400-apparent-mol.wt. subunit. The amount of the 54 000-apparent-mol.wt. subunit detected in the expected position on the gel was found to be inversely proportional to increases in the ionic strength of the applled sample. 2. Human subcomponent C1q on reduction and alkylation, or oxidation, yields equimolar amounts of three chains designated A, B and C [Reid et al. (1972) Biochem. J. 130, 749-763]. The results obtained by Yonemasu & Stroud [(1972) Immunochemistry 9, 545-554], which showed that the 69 000-apparent-mol.wt. subunit was a disulphide-linked dimer of the A and B chains and that the 54 000-apparent-mol.wt. subunit was a disulphide-linked dimer of the C chain, were confirmed. 3. Gel filtration on Sephadex G-200 in 6.0M-guanidinium chloride showed that both types of unreduced subunit were eluted together as a single symmetrical peak of apparent mol.wt. 49 000-50 000 when globular proteins were used as markers. The molecular weights of the oxidized or reduced A, B and C chains have been shown previously to be very similar all being in the range 23 000-24 000 [Reid et al. (1972) Biochem. J. 130, 749-763; Reid (1974) Biochem. J. 141, 189-203]. 4. It is proposed that subcomponent C1q (mol.wt. 410000) is composed of nine non-covalently linked subunits, i.e. six A-B dimers and three C-C dimers. 5. A structure for subcomponent C1q is proposed and is based on the assumption that the collagen-like regions of 78 residues in each of the A, B and C chains are combined to form a triple-helical structure of the same type as is found in collagens.

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Determination of electroosmotic and electrophoretic mobility of DNA and dyes in low ionic strength solutions

Electrophoresis ◽

10.1002/elps.201700281 ◽

2017 ◽

Vol 39 (5-6) ◽

pp. 862-868 ◽

Cited By ~ 2

Author(s):

Joshua Lallman ◽

Rachel Flaugh ◽

Kristy L. Kounovsky-Shafer

Keyword(s):

Ionic Strength ◽

Electrophoretic Mobility ◽

Low Ionic Strength

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Genetically determined polymorphism of the circulating human breast cancer-associated DF3 antigen

Blood ◽

10.1182/blood.v71.2.436.bloodjournal712436 ◽

1988 ◽

Vol 71 (2) ◽

pp. 436-440 ◽

Cited By ~ 1

Author(s):

DF Hayes ◽

H Sekine ◽

D Marcus ◽

CA Alper ◽

DW Kufe

Keyword(s):

Breast Cancer ◽

Electrophoretic Mobility ◽

Core Protein ◽

Human Breast ◽

Mobility Patterns ◽

Multiple Alleles ◽

Molecular Weights ◽

The Core ◽

Electrophoretic Mobilities ◽

Genetically Determined

The murine monoclonal antibody (MAb) DF3 was prepared against a human breast carcinoma. Previous studies have demonstrated that DF3 antigen levels are elevated in plasma of patients with breast cancer. Furthermore, MAb DF3 reacts with circulating glycoproteins of different molecular weights ranging from approximately 300 to 450 kd. The present study demonstrates that plasma DF3 antigen is comprised of at least four moieties with slow (S), intermediate (I), rapid (R) and very rapid (VR) electrophoretic mobilities. The electrophoretic mobility patterns for circulating DF3 antigen differ among individuals. Moreover, DF3 antigen is detectable in urine, and the electrophoretic mobility of the urinary moieties is similar, but not identical, to that in the plasma. Studies in family members suggest that the electrophoretic heterogeneity of plasma DF3 antigen is determined by codominant expression of multiple alleles at a single locus. This locus may code for the core protein of DF3 antigen. These findings thus identify a genetically determined polymorphism of a circulating tumor-associated glycoprotein.

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Conformational Transitions in Escherichia coli Ribosomal RNAs as Visualized by Dedicated STEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100102961 ◽

1988 ◽

Vol 46 ◽

pp. 176-177

Author(s):

J.S. Wall ◽

V. Maridiyan ◽

S. Tumminia ◽

J. Hairifeld ◽

M. Boublik

Keyword(s):

Ionic Strength ◽

Three Dimensional ◽

Conformational Transitions ◽

Dark Field ◽

Dimensional Structure ◽

Ribosomal Rnas ◽

Field Mode ◽

Freeze Dried ◽

High Resolution Images ◽

Low Ionic Strength

The high contrast in the dark-field mode of dedicated STEM, specimen deposition by the wet film technique and low radiation dose (1 e/Å2) at -160°C make it possible to obtain high resolution images of unstained freeze-dried macromolecules with minimal structural distortion. Since the image intensity is directly related to the local projected mass of the specimen it became feasible to determine the molecular mass and mass distribution within individual macromolecules and from these data to calculate the linear density (M/L) and the radii of gyration.2 This parameter (RQ), reflecting the three-dimensional structure of the macromolecular particles in solution, has been applied to monitor the conformational transitions in E. coli 16S and 23S ribosomal RNAs in solutions of various ionic strength.In spite of the differences in mass (550 kD and 1050 kD, respectively), both 16S and 23S RNA appear equally sensitive to changes in buffer conditions. In deionized water or conditions of extremely low ionic strength both appear as filamentous structures (Fig. la and 2a, respectively) possessing a major backbone with protruding branches which are more frequent and more complex in 23S RNA (Fig. 2a).

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An Evaluation of a Plasma Fractionation System

Thrombosis and Haemostasis ◽

10.1055/s-0038-1654486 ◽

1960 ◽

Vol 4 (01) ◽

pp. 031-044

Author(s):

George Y. Shinowara ◽

E. Mary Ruth

Keyword(s):

Biological Activity ◽

Ionic Strength ◽

Plasma Proteins ◽

High Concentration ◽

Significant Evidence ◽

Native Proteins ◽

Mobility Data ◽

Fractionation Procedure ◽

The Individual ◽

Low Ionic Strength

SummaryFour primary fractions comprising at least 97 per cent of the plasma proteins have been critically appraised for evidence of denaturation arising from a low temperature—low ionic strength fractionation system. The results in addition to those referable to the recovery of mass and biological activity include the following: The high solubilities of these fractions at pH 7.3 and low ionic strengths; the compatibility of the electrophoretic and ultracentrifugal data of the individual fractions with those of the original plasma; and the recovery of hemoglobin, not hematin, in fraction III obtained from specimens contaminated with this pigment. However, the most significant evidence for minimum alterations of native proteins was that the S20, w and the electrophoretic mobility data on the physically recombined fractions were identical to those found on whole plasma.The fractionation procedure examined here quantitatively isolates fibrinogen, prothrombin and antithrombin in primary fractions. Results have been obtained demonstrating its significance in other biological systems. These include the following: The finding of 5 S20, w classes in the 4 primary fractions; the occurrence of more than 90 per cent of the plasma gamma globulins in fraction III; the 98 per cent pure albumin in fraction IV; and, finally, the high concentration of beta lipoproteins in fraction II.

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