scholarly journals Submitochondrial localization and asymmetric disposition of two peripheral cyclic nucleotide phosphodiesterases

1982 ◽  
Vol 207 (1) ◽  
pp. 123-132 ◽  
Author(s):  
B Cercek ◽  
M D Houslay
Keyword(s):  
Ionic Strength ◽  
Cyclic Amp ◽  
Outer Membrane ◽  
Liver Mitochondrion ◽  
Sedimentation Coefficient ◽  
High Ionic Strength ◽  
Inner Membrane ◽  
Lysosomal Fraction ◽  
Membrane Enzyme ◽  
Peripheral Proteins

There are two distinct cyclic AMP phosphodiesterases associated with the liver mitochondrion: one with the outer membrane and one with the inner membrane. No activity is associated with the lysosomal fraction. Both of the enzymes are peripheral proteins and can be released from the membranes by high-ionic-strength treatment. Treatment of intact mitochondria with trypsin and insoluble trypsin localizes these enzymes to the cytosol-facing surface of their respective membranes. The enzymes differ in regard to sedimentation coefficient, thermostability and susceptibility to inactivation by trypsin. Both enzymes degrade cyclic AMP and cyclic GMP. Whereas the outer-membrane enzyme displays Michaelis kinetics and appears to be a low-affinity enzyme, the inner-membrane enzyme displays kinetics indicative of apparent negative co-operativity.

scholarly journals Three distinct inner dynein arms in Chlamydomonas flagella: molecular composition and location in the axoneme.

1990 ◽  
Vol 110 (2) ◽  
pp. 379-389 ◽  
Author(s):  
G Piperno ◽  
Z Ramanis ◽  
E F Smith ◽  
W S Sale
Keyword(s):  
Ionic Strength ◽  
Sedimentation Coefficient ◽  
High Ionic Strength ◽  
Molecular Composition ◽  
Electron Microscopic ◽  
Heavy Chains ◽  
Dynein Arms ◽  
And Function ◽  
Atp Binding And Hydrolysis ◽  
A Site

The molecular composition and organization of the row of axonemal inner dynein arms were investigated by biochemical and electron microscopic analyses of Chlamydomonas wild-type and mutant axonemes. Three inner arm structures could be distinguished on the basis of their molecular composition and position in the axoneme as determined by analysis of pf30 and pf23 mutants. The three inner arm structures repeat every 96 nm and are referred to here as inner arms I1, I2, and I3. I1 is proximal to the radial spoke S1, whereas I2 and I3 are distal to spokes S1 and S2, respectively. The mutant pf30 lacks I1 whereas the mutant pf23 lacks both I1 and I2 but has a normal inner arm I3. Each of the six heavy chains that was identified as an inner dynein arm subunit has a site for ATP binding and hydrolysis. Two of the heavy chains together with a polypeptide of 140,000 molecular weight form the inner arm I1 and were extracted from the axoneme as a complex that had a sedimentation coefficient close to 21S at high ionic strength. Different subsets of two of the remaining four heavy chains form the inner arms I2 and I3. These arms at high ionic strength are dissociated as 11S particles that include one heavy chain, one intermediate chain, two light chains, and actin. These and other lines of evidence indicate that the inner arm I1 is different in structure and function from the inner arms I2 and I3.

scholarly journals The mitochondrial localization of coproporphyrinogen III oxidase

1978 ◽  
Vol 176 (1) ◽  
pp. 97-102 ◽  
Author(s):  
B Grandchamp ◽  
N Phung ◽  
Y Nordmann
Keyword(s):  
Ionic Strength ◽  
Rat Liver ◽  
Membrane Binding ◽  
High Ionic Strength ◽  
Alkaline Solutions ◽  
Intermembrane Space ◽  
Mitochondrial Localization ◽  
Inner Membrane ◽  
Membrane Matrix ◽  
Coproporphyrinogen Iii Oxidase

The location of coproporphyrinogen III oxidase in mitochondria was studied in rat liver by using the digitonin method or hypo-osmotic media for fractionation. The enzyme was found in the intermembrane space with a fraction loosely bound to the inner membrane. This fraction was released by washing the inner-membrane-matrix complex with alkaline solutions or solutions of high ionic strength. The enzyme in both fractions had the same Km (0.16 micrometer) for coproporphyrinogen III. When incubation was performed in a medium that avoided destruction of enzyme membrane binding, a dramatic increase in activity was observed after sonication of whole mitochondria or of the inner-membrane-matrix complex.

BINDING OF CHOLECALCIFEROL METABOLITES TO RAT DUODENAL MUCOSA CYTOSOL

1977 ◽  
Vol 84 (2) ◽  
pp. 439-448 ◽  
Author(s):  
A. Ulmann ◽  
M. Brami ◽  
E. Pezant ◽  
M. Garabedian ◽  
J. L. Funck-Brentano
Keyword(s):  
Ionic Strength ◽  
Binding Sites ◽  
Sedimentation Coefficient ◽  
Duodenal Mucosa ◽  
High Ionic Strength ◽  
High Affinity ◽  
25 Hydroxycholecalciferol

ABSTRACT In vitro binding of 25-hydroxycholecalciferol (25-(OH)D3) and 1α,25-dihydroxycholecalciferol (1,25-(OH)2D3) was studied in the duodenal mucosa cytosol of rachitic rats: both 25-(OH)D3 and 1,25-(OH)2D3 bind to a macromolecule (sedimentation coefficient 5.5 to 6 S in low or high ionic strength) with a high affinity (KD at 4°C = 1.2×10−9 m and 2×10−9 m, respectively). In addition, it is concluded from competition and chase experiments that 25-(OH)D3 binding sites differ from that for 1,25-(OH)2D3.

scholarly journals Chromatographic Separation, and Characteristics of Nucleic Acids from HeLa Cells

1961 ◽  
Vol 44 (5) ◽  
pp. 899-910 ◽  
Author(s):  
Lennart Philipson
Keyword(s):  
Sodium Chloride ◽  
Ionic Strength ◽  
Bovine Serum Albumin ◽  
Nucleic Acids ◽  
Hela Cells ◽  
Sedimentation Coefficient ◽  
High Ionic Strength ◽  
Salt Gradient ◽  
Low Ionic Strength ◽  
Phenol Extract

The application of the phenol-duponol method to extraction of nucleic acids from HeLa cells is described. Chromatography of the phenol extract on an esterified bovine serum albumin column with a salt gradient of sodium chloride gives separation of soluble RNA, DNA, and two different high molecular RNA fractions. Ultracentrifugation of the DNA eluted from the column gives a sedimentation coefficient (s20o,w) of 38, which agrees with ultracentrifugation data on the phenol extract. The eluted RNA appears polydisperse at low ionic strength, but at high ionic strength and after alcohol precipitation two fractions with the sedimentation coefficients of 16 and 25 to 29, respectively, were obtained.

Importance of Protease Inhibition in Studies on Purified Factor VIII (Antihaemophilic Factor)

1976 ◽  
Vol 35 (01) ◽  
pp. 186-190 ◽  
Author(s):  
Eugen A. Beck ◽  
Peter Bachmann ◽  
Peter Barbier ◽  
Miha Furlan
Keyword(s):  
Ionic Strength ◽  
Factor Viii ◽  
Gel Filtration ◽  
High Ionic Strength ◽  
Procoagulant Activity ◽  
Carrier Protein ◽  
Protease Inhibition ◽  
Functional Sites ◽  
Molecular Weight Peak ◽  
Von Willebrand

SummaryAccording to some authors factor VIII procoagulant activity may be dissociable from carrier protein (MW~ 2 × 106) by agarose gel filtration, e.g. at high ionic strength. We were able to reproduce this phenomenon. However, addition of protease inhibitor (Trasylol) prevented the appearance of low molecular weight peak of factor VIII procoagulant activity both at high ionic strength and elevated temperature (37°C). We conclude from our results that procoagulant activity and carrier protein (von Willebrand factor, factor VIII antigen) are closely associated functional sites of native factor VIII macro molecule. Consequently, proteolytic degradation should be avoided in functional and structural studies on factor VIII and especially in preparing factor VIII concentrate for therapeutic use.

THE RELATIVE DISTRIBUTION OF THYROXINE, TRIIODOTHYRONINE AND 3,3′,5′-(REVERSE)-TRIIODOTHYRONINE IN VARIOUS FRACTIONS OF THYROGLOBULIN

1978 ◽  
Vol 88 (2) ◽  
pp. 298-305 ◽  
Author(s):  
Peter Laurberg
Keyword(s):  
Ionic Strength ◽  
Guinea Pig ◽  
Sucrose Gradient ◽  
Deae Cellulose ◽  
High Ionic Strength ◽  
Relative Distribution ◽  
Thyroid Extract ◽  
Reverse Triiodothyronine ◽  
Thyroid Secretion ◽  
Stable Iodine

ABSTRACT Thyroglobulin fractions rich and poor in new thyroglobulin were separated by means of DEAE-cellulose chromatography of dog thyroid extracts and by zonal ultracentrifugation in a sucrose gradient of guinea pig thyroid extract incubated at low temperature. The distribution of thyroxine, triiodothyronine and 3,3′,5′-(reverse)-triiodothyronine in hydrolysates of the different fractions was estimated by radioimmunoassays. Following DEAE-cellulose chromatography there was a small but statistically significant increase in the T4/T3 ratio in thyroglobulin fractions eluted at high ionic strength - that is fractions relatively rich in stable iodine but poor in fresh thyroglobulin. There were no differences in the T4/rT3 ratios between the different fractions. The ratios between iodothyronines were almost identical in the various thyroglobulin fractions following zonal ultracentrifugation in a sucrose gradient of cold treated guinea pig thyroid extract. These findings lend no support to the possibility that a relatively high content of triiodothyronines in freshly synthesized thyroglobulin modulates the thyroid secretion towards a preferential secretion of triiodothyronine and 3,3′,5′-(reverse)-triiodothyronine at the expense of the secretion of thyroxine.

scholarly journals Kaolin based protective barrier in municipal landfills against adverse chemo-mechanical loadings

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Partha Das ◽  
Tadikonda Venkata Bharat
Keyword(s):  
Ionic Strength ◽  
High Ionic Strength ◽  
The Self ◽  
Design Parameters ◽  
Layered System ◽  
Geosynthetic Clay Liners ◽  
Clay Liners ◽  
Landfill Liner ◽  
First Time ◽  
Applied Stresses

AbstractIn this work, we assess the self-sealing and swelling ability of the compacted granular bentonite (GB) under an inorganic salt environment and induced overburden stresses from the landfill waste. The laboratory permeation tests with high ionic strength salt solutions reveal that the GB fails to seal and exhibits a significant mechanical collapse under different applied stresses. The applicability of GB in the form of geosynthetic clay liners as the bottom liner facilities in landfills that produce high ionic strength salt leachates, therefore, remains a serious concern. We propose an additional barrier system based on kaolin, for the first time, to address this problem. The proposed kaolin-GB layered system performs satisfactorily in terms of its sealing and swelling ability even in adverse saline conditions and low overburden stresses. The kaolin improves the osmotic efficiency of the self and also helps the underlying GB layer to seal the inter-granular voids. The estimated design parameters by through-diffusion test suggest that the kaolin-GB layered system effectively attenuates the permeant flux and suitable as a landfill liner.

scholarly journals High ionic strength dissociation assay (HISDA) for high drug tolerant immunogenicity testing

Bioanalysis ◽  
2020 ◽  
Author(s):  
Gregor Jordan ◽  
Alexander Pöhler ◽  
Florence Guilhot ◽  
Meike Zaspel ◽  
Roland F Staack
Keyword(s):  
Ionic Strength ◽  
Acid Treatment ◽  
Structural Integrity ◽  
Drug Tolerance ◽  
High Ionic Strength ◽  
Acid Dissociation ◽  
High Drug ◽  
Overnight Incubation ◽  
Antidrug Antibody ◽  
High Doses

Aim: Antidrug antibody (ADA) assessment may be challenged in studies that involve the administration of high doses of biotherapeutics and/or with long half-lives. In such cases, ADA assays with optimized drug tolerance are desired. Material & Methods: We evaluated the use of MgCl2 to develop high ionic strength dissociation assays in two investigational examples (bridging enzyme-linked immunosorbent ADA assays) to attain high drug tolerance while maintaining best possible structural integrity of ADAs. Results: Both ADA-bridging assays treated with MgCl2 showed improved drug tolerance and higher signal-to-blank values compared with overnight incubation or acid treatment. Conclusion: The use of MgCl2 treatment in ADA-bridging assays provides a sensitive, drug tolerant and easy-to-use alternative in cases where acid dissociation is not possible or unwanted.

scholarly journals High salt compatible oxyanion receptors by dual ion imprinting

2020 ◽  
Vol 11 (16) ◽  
pp. 4246-4250 ◽  
Author(s):  
Sudhirkumar Shinde ◽  
Mona Mansour ◽  
Anil Incel ◽  
Liliia Mavliutova ◽  
Celina Wierzbicka ◽  
...  
Keyword(s):  
Ionic Strength ◽  
Ion Pair ◽  
High Ionic Strength ◽  
High Salt ◽  
Ion Uptake ◽  
Ion Imprinting

Imprinting of an ion-pair in presence of mutually compatible anion and cation host monomers leads to polymers showing enhanced ion uptake in competitive high ionic strength buffers.

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