scholarly journals AN INTEGRATED MORPHOLOGICAL AND BIOCHEMICAL STUDY OF A PURIFIED PREPARATION OF THE SUCCINATE AND DPNH OXIDASE SYSTEM

1957 ◽  
Vol 3 (6) ◽  
pp. 1023-1036 ◽  
Author(s):  
Eric G. Ball ◽  
Russell J. Barrnett
Keyword(s):  
Light Scattering ◽  
Electron Micrographs ◽  
Heart Muscle ◽  
Enzyme Preparation ◽  
Biochemical Study ◽  
Dry Weight ◽  
Mitochondrial Membranes ◽  
Oxidase System ◽  
The Core ◽  
Morphological Appearance

Electron micrographs of a purified succinate and DPNH oxidase system prepared from heart muscle reveal that it has a vesicular appearance and is membranous in nature. In keeping with its vesicular appearance is the fact that light scattering by this preparation shows marked changes as the molarity of the suspending medium is altered. Treatment of this preparation with 0.5 per cent deoxycholate solutions removes a large part of the lipide material, which comprises almost half of the dry weight of the preparation. The residue, which still contains the "core" of the cytochrome electron transmitter system, as shown by spectroscopic and enzymatic experiments, is still structured and is membranous in morphological appearance. It is concluded that the enzyme preparation is largely composed of fragmented mitochondrial membranes, and some of the consequences of the localization of the succinate and DPNH oxidase systems in or on these membranes are discussed.

Intramitochondrial Viruses of Reptilian Cell Origin

1972 ◽  
Vol 30 ◽  
pp. 318-319
Author(s):  
Philip D. Lunger ◽  
H. Fred Clark
Keyword(s):  
Particle Production ◽  
Outer Zone ◽  
Density Variation ◽  
Core Region ◽  
Mitochondrial Membranes ◽  
Virus Particles ◽  
The Core ◽  
Vipera Russelli ◽  
Maturation Stages ◽  
Type Particle

In the course of fine structure studies of spontaneous “C-type” particle production in a viper (Vipera russelli) spleen cell line, designated VSW, virus particles were frequently observed within mitochondria. The latter were usually enlarged or swollen, compared to virus-free mitochondria, and displayed a considerable degree of cristae disorganization.Intramitochondrial viruses measure 90 to 100 mμ in diameter, and consist of a nucleoid or core region of varying density and measuring approximately 45 mμ in diameter. Nucleoid density variation is presumed to reflect varying degrees of condensation, and hence maturation stages. The core region is surrounded by a less-dense outer zone presumably representing viral capsid.Particles are usually situated in peripheral regions of the mitochondrion. In most instances they appear to be lodged between loosely apposed inner and outer mitochondrial membranes.

scholarly journals Light-Scattering Simulations from Spherical Bimetallic Core–Shell Nanoparticles

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 359
Author(s):  
Francesco Ruffino
Keyword(s):  
Optical Properties ◽  
Light Scattering ◽  
Bimetallic Nanoparticles ◽  
Dominant Role ◽  
Scattered Light ◽  
Specific Interaction ◽  
Surface Enhanced Raman Spectroscopy ◽  
Localized Surface Plasmon ◽  
Core Shell ◽  
The Core

Bimetallic nanoparticles show novel electronic, optical, catalytic or photocatalytic properties different from those of monometallic nanoparticles and arising from the combination of the properties related to the presence of two individual metals but also from the synergy between the two metals. In this regard, bimetallic nanoparticles find applications in several technological areas ranging from energy production and storage to sensing. Often, these applications are based on optical properties of the bimetallic nanoparticles, for example, in plasmonic solar cells or in surface-enhanced Raman spectroscopy-based sensors. Hence, in these applications, the specific interaction between the bimetallic nanoparticles and the electromagnetic radiation plays the dominant role: properties as localized surface plasmon resonances and light-scattering efficiency are determined by the structure and shape of the bimetallic nanoparticles. In particular, for example, concerning core-shell bimetallic nanoparticles, the optical properties are strongly affected by the core/shell sizes ratio. On the basis of these considerations, in the present work, the Mie theory is used to analyze the light-scattering properties of bimetallic core–shell spherical nanoparticles (Au/Ag, AuPd, AuPt, CuAg, PdPt). By changing the core and shell sizes, calculations of the intensity of scattered light from these nanoparticles are reported in polar diagrams, and a comparison between the resulting scattering efficiencies is carried out so as to set a general framework useful to design light-scattering-based devices for desired applications.

Image Processing of Electron Micrographs for Light Scattering Calculations

Cornea ◽  
1993 ◽  
Vol 12 (6) ◽  
pp. 466-474 ◽  
Author(s):  
D E Freund ◽  
R L McCally ◽  
A D Goldfinger ◽  
R A Farrell
Keyword(s):  
Image Processing ◽  
Light Scattering ◽  
Electron Micrographs

scholarly journals Polar ice stratigraphy from laser-light scattering: scattering from meltwater

1994 ◽  
Vol 40 (136) ◽  
pp. 504-508 ◽  
Author(s):  
Michael Ram ◽  
Matthias Illing
Keyword(s):  
Light Scattering ◽  
Sample Size ◽  
Tree Ring ◽  
Laser Light ◽  
Ice Core ◽  
Ice Cores ◽  
Laser Light Scattering ◽  
Polar Ice ◽  
The Core ◽  
Considerable Success

Abstract We describe a new laser-light-scattering instrument for measuring variations in dust concentration along polar ice cores. We have used this instrument with considerable success on the GISP2 ice core from central Greenland. Reproducibility is excellent and the required ice-sample size is relatively small. When combined with visual stratigraphy and ECM, the distinct annual spring/ summer dust peaks we observe can be used to date the core with tree-ring-like precision.

scholarly journals Polar ice stratigraphy from laser-light scattering: scattering from meltwater

1994 ◽  
Vol 40 (136) ◽  
pp. 504-508
Author(s):  
Michael Ram ◽  
Matthias Illing
Keyword(s):  
Light Scattering ◽  
Sample Size ◽  
Tree Ring ◽  
Laser Light ◽  
Ice Core ◽  
Ice Cores ◽  
Laser Light Scattering ◽  
Polar Ice ◽  
The Core ◽  
Considerable Success

AbstractWe describe a new laser-light-scattering instrument for measuring variations in dust concentration along polar ice cores. We have used this instrument with considerable success on the GISP2 ice core from central Greenland. Reproducibility is excellent and the required ice-sample size is relatively small. When combined with visual stratigraphy and ECM, the distinct annual spring/ summer dust peaks we observe can be used to date the core with tree-ring-like precision.

DISSOCIATION AND SUBUNIT SIZE OF β-LIPOVITELLIN

1965 ◽  
Vol 43 (6) ◽  
pp. 661-670 ◽  
Author(s):  
W. H. Cook ◽  
R. A. Wallace
Keyword(s):  
Molecular Weight ◽  
Light Scattering ◽  
Dissociation Constants ◽  
Dry Weight ◽  
Ph Values ◽  
Scattering Measurements ◽  
Solvent Displacement ◽  
Weight Method ◽  
Kinetics Of ◽  
Good Agreement

Dissociation of β-lipovitellin was detectable at pH 5.8 and increased linearly with pH. Light-scattering measurements at different pH values were consistent with a molecular weight of 2.27 × 105 for the subunit and twice this value for the associated form, confirming that it is a monomer–dimer system. This value for the molecular weight of the dimer is somewhat higher than previously reported (4.0 × 105) partly because a solvent displacement correction was used in estimating concentration by a dry weight method. Dissociation constants evaluated from light-scattering measurements and by ultracentrifugal separation were 22 × 10−6 and 29 × 10−6 respectively, in good agreement with provisional values already reported. Preliminary studies on the kinetics of this reaction indicate that, when the pH is altered, dissociation reaches the new equilibrium in about 0.5 minute but that reassociation requires about 50 minutes.

scholarly journals Isolation and characterization of two sialoproteins present only in bone calcified matrix

1985 ◽  
Vol 232 (3) ◽  
pp. 715-724 ◽  
Author(s):  
A Franzén ◽  
D Heinegård
Keyword(s):  
Sialic Acid ◽  
Core Protein ◽  
Deae Cellulose ◽  
Sedimentation Coefficient ◽  
Dry Weight ◽  
Enzyme Linked Immunosorbent Assay ◽  
Bovine Bone ◽  
Guanidinium Chloride ◽  
The Core ◽  
Isolation And Characterization

Two different sialoproteins were isolated from the mineralized matrix of bovine bone by using extraction with guanidinium chloride first without and then with EDTA. The sialoproteins were purified by chromatography on DEAE-cellulose eluted with a sodium acetate gradient in 7 M-urea, pH 6. Two sialoproteins (I and II) were then separated by chromatography on DEAE-cellulose eluted with a sodium chloride gradient in 7 M-urea, pH 4. The ratio between recovered sialoprotein I and II was 1:5. The chemical analysis of the two sialoproteins showed that they differed. Both, however, had very high contents of aspartic acid/asparagine and glutamic acid/glutamine though they differed markedly in contents of leucine and glycine. Both sialoproteins contained phosphate, sialoprotein I more than sialoprotein II. Content of sialic acid was substantially higher in the more prominent sialoprotein II (13.4% of dry weight) than in sialoprotein I (4.8% of dry weight). The peptide patterns produced by trypsin digests of [125I]iodinated sialoproteins I and II showed both structural similarities and structural differences. Sialoprotein II, being the major component, was characterized further. Its molecular mass was 57300 Da determined by sedimentation-equilibrium centrifugation in 6 M-guanidinium chloride, and its sedimentation coefficient (S0(20),w) was 2.53 S. Upon rotary shadowing, sialoprotein II appeared as an extended rod, having a core with an average length of 40 nm. Two types of oligosaccharides, N-glycosidically and O-glycosidically linked to the core protein, were isolated from sialoprotein II. Contents of mannose and sialic acid in the O-linked oligosaccharide were surprisingly high. Antibodies against sialoprotein II were raised in rabbits and an enzyme-linked immunosorbent assay was developed. Antigenicity of sialoprotein II was not affected by reduction and alkylation, was only partially lost upon trypsin digestion and was completely lost upon fragmentation of the core protein by alkaline-borohydride treatment, indicating that all antigenic sites were located in the protein portion. Sialoprotein I expectedly showed only partial immunological cross-reactivity with sialoprotein II. The quantity of sialoprotein II in bone extracts was found to be about 1.5 mg/g wet wt. of bone, but the protein was not detected in extracts of a number of other bovine tissues i.e. aorta, cartilage, dentine, kidney, liver, muscle, sclera, skin and tendon.

Effects of carnitine on acetyl-CoA oxidation by heart muscle mitochondria

1964 ◽  
Vol 206 (3) ◽  
pp. 531-535 ◽  
Author(s):  
Irving B. Fritz ◽  
Kenneth T. N. Yue
Keyword(s):  
Heart Muscle ◽  
Additional Data ◽  
Transfer System ◽  
Carnitine Acetyltransferase ◽  
Mitochondrial Membranes ◽  
Acetyl Coa ◽  
Muscle Mitochondria ◽  
Group Movement ◽  
Acetyl Group ◽  
Shuttle System

Acetyl-1-C14-CoA was oxidized by heart muscle mitochondria incubated in the absence of ATP and carnitine at a rate approximately 1/100 that at which acetic acid-1-C14 was converted to CO2 in the presence of ATP. Carnitine addition increased the degradation of acetyl-1-C14-CoA by over 50-fold whereas it had no effect on acetate-1-C14 oxidation under conditions described. Carnitine simultaneously augmented oxygen uptake by heart mitochondria in the absence of ATP when acetyl-CoA was the substrate, but had little or no effect on respiration when acetate was the substrate in the presence or absence of ATP. Acetylcarnitine decreased the carnitine enhancement of acetyl-1-C14-CoA conversion to CO2, most likely by isotope dilution via operation of the carnitine acetyltransferase reaction: acetyl-CoA + carnitine ⇆ acetylcarnitine + CoA. It was tentatively concluded that the acetyl group of acetyl-CoA cannot readily penetrate mitochondrial barriers in the absence of a suitable transfer system, but that carnitine acetyltransferase and carnitine may function as a shuttle system to facilitate acetyl-group movement across mitochondrial membranes. Additional data presented demonstrate that carnitine influences the metabolism of the acyl groups of other chain-length acyl-CoA derivatives.

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