scholarly journals Structural localization in the classical and quantum Fermi–Pasta–Ulam model

2020 ◽  
Vol 30 (3) ◽  
pp. 033116
Author(s):  
Graziano Amati ◽  
Tanja Schilling
Keyword(s):  
Structural Localization

Fine Structural Localization of Acyltransferases Involved in Lipid Synthesis in Intestinal Mucosa.

1970 ◽  
Vol 28 ◽  
pp. 54-55
Author(s):  
R. J. Barrnett ◽  
J. A. Higgins
Keyword(s):  
Smooth Endoplasmic Reticulum ◽  
Lipid Synthesis ◽  
Mucosal Cell ◽  
Structural Localization ◽  
Morphological Studies ◽  
Mucosal Cells ◽  
Initial Appearance ◽  
Sh Group ◽  
Hydrolysis Of ◽  
Intestinal Mucosal Cells

The main products of intestinal hydrolysis of dietary triglycerides are free fatty acids and monoglycerides. These form micelles from which the lipids are absorbed across the mucosal cell brush border. Biochemical studies have indicated that intestinal mucosal cells possess a triglyceride synthesising system, which uses monoglyceride directly as an acylacceptor as well as the system found in other tissues in which alphaglycerophosphate is the acylacceptor. The former pathway is used preferentially for the resynthesis of triglyceride from absorbed lipid, while the latter is used mainly for phospholipid synthesis. Both lipids are incorporated into chylomicrons. Morphological studies have shown that during fat absorption there is an initial appearance of fat droplets within the cisternae of the smooth endoplasmic reticulum and that these subsequently accumulate in the golgi elements from which they are released at the lateral borders of the cell as chylomicrons.We have recently developed several methods for the fine structural localization of acyltransferases dependent on the precipitation, in an electron dense form, of CoA released during the transfer of the acyl group to an acceptor, and have now applied these methods to a study of the fine structural localization of the enzymes involved in chylomicron lipid biosynthesis. These methods are based on the reduction of ferricyanide ions by the free SH group of CoA.

scholarly journals ULTRASTRUCTURAL LOCALIZATION OF Mg++-DEPENDENT DINITROPHENOL-STIMULATED ADENOSINE TRIPHOSPHATASE IN HUMAN BLOOD PLATELETS

1967 ◽  
Vol 15 (5) ◽  
pp. 267-272 ◽  
Author(s):  
VICTOR G. VETHAMANY ◽  
SYDNEY S. LAZARUS
Keyword(s):  
Enzyme Activity ◽  
Plasma Membrane ◽  
Human Blood ◽  
Adenosine Triphosphatase ◽  
Blood Platelets ◽  
Ultrastructural Localization ◽  
Human Platelets ◽  
Structural Localization ◽  
Adenosine Triphosphatase Activity ◽  
Human Blood Platelets

Fine structural localization of adenosine triphosphatase activity was studied in human platelets briefly fixed in cold formol calcium and then incubated in lead medium with added dinitrophenol. Under these conditions, the Mg++-dependent dinitrophenol-stimulated adenosine triphosphatase of platelet mitochondria was demonstrated, but neither granules nor plasma membrane showed enzyme activity.

Biogenesis of Plasma Membranes in Salt Glands of Salt-Stressed Domestic Ducklings: Localization of Acyltransferase Activity

1972 ◽  
Vol 11 (3) ◽  
pp. 855-873
Author(s):  
A. M. LEVINE ◽  
JOAN A. HIGGINS ◽  
R. J. BARRNETT
Keyword(s):  
Plasma Membrane ◽  
Plasma Membranes ◽  
Specific Activity ◽  
Salt Gland ◽  
Secretory Cells ◽  
Salt Glands ◽  
Acyltransferase Activity ◽  
Structural Localization ◽  
Differentiated Cells ◽  
Golgi Membranes

In response to salt water stress there is a marked increase in the plasma membranes of the epithelial secretory cells of the salt glands of domestic ducklings. In the present study, the fine-structural localization of the acyltransferases involved in synthesis of phospholipids has been investigated in this tissue during this increased biogenesis of plasma membranes. The specific activity of the acyltransferases of the salt gland rose in response to salt stress, and this preceded the rapid increase in weight and cellular differentiation. After the weight increase of the gland became established, the specific activity of the acyltransferases declined, but the total activity remained constant. Salt gland tissue fixed in a mixture of glutaraldehyde and formaldehyde retained 35% of the acyltransferase activity of unfixed tissue. Cytochemical studies of the localization of acyltransferase activity in fixed and unfixed salt gland showed reaction product associated only with the lamellar membranes of the Golgi complex. This localization occurred in partially differentiated cells from salt-stressed glands to the greatest extent; and to only a small extent in cells of control tissue from unstressed salt glands. Omission of substrates resulted in absence of reaction product in association with the Golgi membranes. In addition, vesicles having limiting membranes morphologically similar to the plasma membrane occurred between the Golgi region and the plasma membrane in the partially differentiated cells. The phospholipid component of the plasma membrane appears therefore to be synthesized in association with the Golgi membranes and the membrane packaged at this site from which it moves in the form of vesicles to fuse with the pre-existing plasma membrane.

Characterization of antibodies as probes for structural and biochemical studies of tektins from ciliary and flagellar microtubules

1987 ◽  
Vol 88 (4) ◽  
pp. 453-466
Author(s):  
R.W. Linck ◽  
M.J. Goggin ◽  
J.M. Norrander ◽  
W. Steffen
Keyword(s):  
Immunofluorescence Microscopy ◽  
Strongylocentrotus Purpuratus ◽  
Body Region ◽  
Two Dimensional ◽  
Structural Localization ◽  
Lytechinus Pictus ◽  
Sds Page ◽  
Nuclear Structures ◽  
Sea Urchin Sperm

Rabbit antibodies raised and purified against three tektins, proteins of flagellar doublet microtubules from sea-urchin sperm (Lytechinus pictus and Strongylocentrotus purpuratus), were used to study tektin biochemistry and their structural localization. Doublet microtubules were fractionated into tektin filaments and separated by SDS-PAGE into three major tektin polypeptide bands (Mr = 47, 51 and 55 (X 10(3)), which were used to immunize rabbits. Antibodies against each tektin (anti-tektins) were affinity-purified and then characterized by two-dimensional isoelectric focusing/SDS-PAGE immunoblotting and by immunofluorescence microscopy. In two-dimensional immunoblots of 0.5% Sarkosyl-resistant fractions of flagellar microtubules, the antibody against the 55 X 10(3) Mr tektin (anti-55) stained one major polypeptide of 55 X 10(3) Mr and pI 6.9, anti-51 stained two polypeptides of 51 X 10(3) Mr and pI approximately 6.15, and anti-47 stained one major polypeptide of 47 X 10(3) Mr and pI 6.15. The anti-tektins also stained several minor neighbouring polypeptides, which may be isoelectric variants, novel tektins or unrelated proteins. Furthermore, anti-47 crossreacted with the major 55 X 10(3) Mr polypeptide. By immunofluorescence microscopy all three anti-tektins stained methanol-fixed echinoderm sperm flagella and embryonic cilia. In addition, anti-47 and anti-55 stained unfixed, demembranated axonemes. Besides staining axonemes, all anti-tektins labelled the basal body region, and anti-51 labelled the sperm head envelope. These results indicate that the tektins are a complex family of proteins that are components of axonemal microtubules and possibly other cytoplasmic and nuclear structures.

Structural Localization of Light Chain Amyloidogenicity

2004 ◽  
pp. 52-54
Author(s):  
A Solomon ◽  
C Murphy ◽  
J Wall ◽  
A Tomaszewski ◽  
B Crombie
Keyword(s):  
Light Chain ◽  
Structural Localization

scholarly journals Immunocytochemical localization of histamine in secretory granules of rat peritoneal mast cells with conventional or rapid microwave fixation and an ultrastructural post-embedding immunogold technique.

1992 ◽  
Vol 40 (9) ◽  
pp. 1247-1256 ◽  
Author(s):  
G R Login ◽  
S J Galli ◽  
A M Dvorak
Keyword(s):  
Electron Microscopy ◽  
Mast Cells ◽  
Guinea Pig ◽  
Secretory Granules ◽  
Fixation Method ◽  
Structural Localization ◽  
Thin Sections ◽  
Aldehyde Fixation ◽  
Peritoneal Mast Cells ◽  
Rat Peritoneal Mast Cells

We used a post-embedding immunogold labeling approach to define the fine-structural localization of histamine in rat peritoneal mast cells that were fixed using either standard aldehyde fixation or a fast microwave-aldehyde fixation method. Specimens were processed routinely for electron microscopy. Thin sections were exposed first to guinea pig antihistamine antiserum and then to gold-conjugated goat IgG directed against guinea pig IgG. By transmission electron microscopy, gold particles were localized to the matrix of cytoplasmic granules. Control sections treated with non-immune sera did not show labeling of mast cells. Adsorption of antihistamine antiserum with purified histamine or histamine bound to agarose showed a significant reduction (p less than 0.005) in granule staining. We also confirmed that our isolation procedures yielded functionally competent mast cells which released histamine when stimulated with sheep anti-rat IgE antiserum or with compound 48/80. These studies define the conditions of fixation for electron microscopy that are appropriate for the localization of histamine in the granule matrix of rat peritoneal mast cells.

scholarly journals THE FINE STRUCTURAL LOCALIZATION OF ACETYLCHOLINESTERASE ACTIVITY IN THE RETINA AND OPTIC NERVE OF RABBITS

1971 ◽  
Vol 19 (2) ◽  
pp. 85-96 ◽  
Author(s):  
E. REALE ◽  
L. LUCIANO ◽  
M. SPITZNAS
Keyword(s):  
Endoplasmic Reticulum ◽  
Optic Nerve ◽  
Ganglion Cells ◽  
Plexiform Layer ◽  
Amacrine Cells ◽  
Acetylcholinesterase Activity ◽  
Horizontal Cells ◽  
Histochemical Reaction ◽  
Fiber Layer ◽  
Structural Localization

In the rabbit retina acetylcholinesterase activity is localized in the perinuclear cisterna, in the cisternae of the rough surfaced endoplasmic reticulum and in the Golgi apparatus of ganglion cells and amacrine cells. The histochemical reaction is positive also in the rough surfaced endoplasmic reticulum of some horizontal cells. The highest activity is seen in the internal plexiform layer; because of artifacts caused by the diffusion of the enzyme, a clear demonstration of relation of the positivity to one or the other regular components of this layer, however, is not possible. Myelinated fibers which exhibit acetylcholinesterase activity and are most probably efferent are found in the internal plexiform layer. In the retinal nerve fiber layer and in the optic nerve only a few fibers show a positive reaction.

Sign in / Sign up

Export Citation Format

Share Document