Acute catabolism of leukocyte lipid bodies: characterization of a nordihydroguaiaretic acid (NDGA)-induced proteasomal-dependent model

2021 ◽  
pp. 102320
Author(s):  
Maria N. de Lira ◽  
Lukas Bolini ◽  
Natália RT Amorim ◽  
Hercules A Silva-Souza ◽  
Bruno L Diaz ◽  
...  
Keyword(s):  
Nordihydroguaiaretic Acid ◽  
Lipid Bodies ◽  
Dependent Model

scholarly journals Molecular cloning and characterization of an almond 9-hydroperoxide lyase, a new CYP74 targeted to lipid bodies*

2005 ◽  
Vol 56 (419) ◽  
pp. 2321-2333 ◽  
Author(s):  
Giovanni Mita ◽  
Angela Quarta ◽  
Pasqua Fasano ◽  
Angelo De Paolis ◽  
Gian Pietro Di Sansebastiano ◽  
...  
Keyword(s):  
Molecular Cloning ◽  
Hydroperoxide Lyase ◽  
Lipid Bodies

scholarly journals Radar characterization of the basal interface across the grounding zone of an ice-rise promontory in East Antarctica

2012 ◽  
Vol 53 (60) ◽  
pp. 29-34 ◽  
Author(s):  
Kenichi Matsuoka ◽  
Frank Pattyn ◽  
Denis Callens ◽  
Howard Conway
Keyword(s):  
East Antarctica ◽  
Ice Thickness ◽  
Ice Shelf ◽  
Temperature Dependent ◽  
Flow Models ◽  
Radar Method ◽  
Dronning Maud Land ◽  
Dependent Model ◽  
Temperature Dependent Model

AbstractRadar power returned from the basal interface along a 42 km long profile over an ice-rise promontory and the adjacent Roi Baudouin ice shelf, Dronning Maud Land, East Antarctica, is analyzed to infer spatial variations in basal reflectivity and hence the basal environment. Extracting basal reflectivity from basal returned power requires an englacial attenuation model. We estimate attenuation in two ways: (1) using a temperature-dependent model with input from thermomechanical ice-flow models; and (2) using a radar method that linearly approximates the geometrically corrected returned power with ice thickness. The two methods give different results. We argue that attenuation calculated using a modeled temperature profile is more robust than the widely used radar method, especially in locations where depth-averaged attenuation varies spatially or where the patterns of basal reflectivity correlate with the patterns of the ice thickness.

Purification and Partial Characterization of Rat Liver Lipoxygenase

1987 ◽  
Vol 42 (10) ◽  
pp. 1343-1348 ◽  
Author(s):  
Pedro Macias ◽  
M. Carmen Pinto
Keyword(s):  
Molecular Weight ◽  
Enzyme Activity ◽  
Rat Liver ◽  
Polymorphonuclear Leukocytes ◽  
Fluorescence Spectra ◽  
Nordihydroguaiaretic Acid ◽  
Maximum Activity ◽  
Absorption And Fluorescence Spectra ◽  
Lipoxygenase Inhibitor

Abstract Lipoxygenase was purified from rat liver cytosolic fraction by a method involving two successive chromatographic steps on Sephacryl S-200 and Phenyl Sepharose CL-4B. The enzyme has a molecular weight of 96 Kdal and it seems to be composed of two identical subunits. Chromatofocusing of the enzyme revealed a single band of activity at pi 6.3. The enzyme activity of the purified fraction showed maximum activity at pH 7.0 with a Km for linoleic acid of 1.4 μM and is competitively inhibited by the specific lipoxygenase inhibitor nordihydroguaiaretic acid. The purified enzyme shows absorption and fluorescence spectra similar to those of lipoxygenase from other sources. However, the molecular weight of lipoxygenase purified from liver is found to be different from that of the enzyme from polymorphonuclear leukocytes. It is suggested that there are different isoenzymes of lipoxygenases in mammals.

Isolation and physicochemical characterization of the half-unit membranes of oilseed lipid bodies

1990 ◽  
Vol 67 (6) ◽  
pp. 353-361 ◽  
Author(s):  
T. J. Jacks ◽  
T. P. Hensarling ◽  
J. N. Neucere ◽  
L. Y. Yatsu ◽  
R. H. Barker
Keyword(s):  
Physicochemical Characterization ◽  
Lipid Bodies

scholarly journals Characterization of lipases from the lipid bodies and microsomal membranes of erucic acid-free oilseed-rape (Brassica napus) cotyledons

1988 ◽  
Vol 249 (3) ◽  
pp. 687-693 ◽  
Author(s):  
M J Hills ◽  
D J Murphy
Keyword(s):  
Brassica Napus ◽  
Oilseed Rape ◽  
Polyacrylamide Gel Electrophoresis ◽  
Lipid Body ◽  
Linear Increase ◽  
Lipid Bodies ◽  
Ph Optimum ◽  
Triacylglycerol Lipase ◽  
Microsomal Membranes

Lipase (triacylglycerol lipase, EC 3.1.1.3) activities have been reported previously in the lipid body and microsomal membranes of oilseed-rape (Brassica napus cv. Andor) seedlings, but conflicting data made it unclear whether there was one lipase in the lipid bodies, with the microsomal activity being attributable to fragments of lipid-body membrane, or if there were two separate lipase activities. In the present study, simultaneous characterization of the lipases under identical conditions showed they differed substantially in their pH-activity curves, kinetics and substrate specificities. (1) The kinetics of the microsomal lipase showed that the rate of lipolysis reached a plateau at concentrations above 5 mM, whereas the lipid-body lipase showed a linear increase in activity with substrate concentration up to 20 mM. (2) The pH optimum of the microsomal lipase was 7.5, whereas that of the lipid-body lipase was 9.0. The microsomal lipase was greatly inhibited at higher pH values, whereas the lipid-body lipase was much less affected. (3) Activity of the microsomal lipase was greatly diminished when substrates with longer chain length were used, and enhanced 4-fold if the substrates contained a single double bond. The lipid-body lipase was relatively unaffected by the type of fatty acid in the triacylglycerol. (4) SDS/polyacrylamide-gel electrophoresis showed little or no cross-contamination of the lipid-body and microsomal fractions. (5) The microsomal lipase activity comprised 75-80% of the total extracted.

On theory dependence of truth in measurement

2021 ◽  
pp. 1-19
Author(s):  
Alessandro Giordani ◽  
Luca Mari
Keyword(s):  
Model Based ◽  
Measurement Results ◽  
Dependent Model ◽  
Definition Of ◽  
Sense And Reference

Abstract Measurement results are stated in terms of sentences ascribing measured values, as obtained via measurement processes, to measurands, as defined by measuring agents. Since both the definition of the measurands and the characterization of the processes depend on models constructed on the basis of relevant theories, the issue arises of the theory dependence of the truth of those sentences. This paper aims at assessing the question by introducing suitable distinctions about the sense and reference of the terms used to refer to individual and general quantities, in a framework where measurement is construed as an agent-dependent, model-based, purpose-driven activity.

scholarly journals Ultrastructural characterization of microlipophagy induced by the interaction of vacuoles and lipid bodies around generative and sperm cells in Arabidopsis pollen

PROTOPLASMA ◽  
2020 ◽  
Vol 258 (1) ◽  
pp. 129-138
Author(s):  
Kae Akita ◽  
Tomoko Takagi ◽  
Keiko Kobayashi ◽  
Kazuyuki Kuchitsu ◽  
Tsuneyoshi Kuroiwa ◽  
...  
Keyword(s):  
Generative Cell ◽  
Lipid Body ◽  
Sperm Cells ◽  
Lipid Bodies ◽  
Pollen Maturation ◽  
Ultrastructural Characterization ◽  
Pollen Stage ◽  
And Function ◽  
Arabidopsis Pollen

AbstractDuring pollen maturation, various organelles change their distribution and function during development as male gametophytes. We analyzed the behavior of lipid bodies and vacuoles involved in lipophagy in Arabidopsis pollen using serial section SEM and conventional TEM. At the bicellular pollen stage, lipid bodies in the vegetative cells lined up at the surface of the generative cell. Vacuoles then tightly attached, drew in, and degraded the lipid bodies and eventually occupied the space of the lipid bodies. Degradation of lipid began before transfer of the entire contents of the lipid body. At the tricellular stage, vacuoles instead of lipid bodies surrounded the sperm cells. The degradation of lipid bodies is morphologically considered microautophagy. The atg2-1 Arabidopsis mutant is deficient in one autophagy-related gene (ATG). In this mutant, the assembly of vacuoles around sperm cells was sparser than that in wild-type pollen. The deficiency of ATG2 likely prevents or slows lipid degradation, although it does not prevent contact between organelles. These results demonstrate the involvement of microlipophagy in the pollen development of Arabidopsis.

scholarly journals Glucansucrase catalyzed synthesis and functional characterization of nordihydroguaiaretic acid glucosides

2019 ◽  
Vol 120 ◽  
pp. 69-76 ◽  
Author(s):  
Johannes Nolte ◽  
Lara-Alina Pöttgen ◽  
Julia Sperlich ◽  
Alessandra Grossert ◽  
Alexander Kempa ◽  
...  
Keyword(s):  
Functional Characterization ◽  
Nordihydroguaiaretic Acid

scholarly journals Improved Parametric Models for Explosion Pressure Signals Derived From Large Datasets

2020 ◽  
Vol 91 (3) ◽  
pp. 1752-1762
Author(s):  
Julie Schnurr ◽  
Keehoon Kim ◽  
Milton A. Garces ◽  
Arthur Rodgers
Keyword(s):  
Forensic Analysis ◽  
Parametric Models ◽  
Model Parameters ◽  
Large Set ◽  
Least Squares Regression ◽  
Explosion Pressure ◽  
Atmospheric Propagation ◽  
Dependent Model ◽  
Fitting In

Abstract Accurate recording and characterization of explosion-induced pressure signals are key components of the forensic analysis of explosion events in the atmosphere. Parametric overpressure models based on several key waveform features (peak overpressure, positive pulse duration, and impulse) are widely used to estimate explosion energy in terms of trinitrotoluene equivalent yield. However, those models are often developed by a limited dataset, including only a few events or recordings at relatively short propagation distances. Here, we develop empirical waveform-parameter models based on a regression analysis of a large set of data curated from four chemical explosion experiments including 16 detonations. We measured peak overpressure and impulse for positive and negative phases from ∼1000 pressure signals recorded at local ranges (<20  km) with scaled distance up to 8000  m/kg1/3. The measured waveform parameters showed large variation with respect to observing distances indicating the effects of atmospheric propagation. In this study, a second-order polynomial model was used in a least-squares regression to account for those propagation effects and to improve data fitting. In addition to model parameters for waveform features, we also determined range-dependent model uncertainties based on data variance. The model uncertainty represents the prediction error of our models and can be critical to evaluating the uncertainty of yield estimate.

Sign in / Sign up

Export Citation Format

Share Document