scholarly journals Composition-function analysis of HDL subpopulations: influence of lipid composition on particle functionality

2020 ◽  
Vol 61 (3) ◽  
pp. 306-315 ◽  
Author(s):  
Katrin Niisuke ◽  
Zsuzsanna Kuklenyik ◽  
Katalin V. Horvath ◽  
Michael S. Gardner ◽  
Christopher A. Toth ◽  
...  
Keyword(s):  
Lipid Composition ◽  
Cholesterol Efflux ◽  
Neutral Lipids ◽  
Function Analysis ◽  
Binding Capacity ◽  
Relative Concentration ◽  
Lipid Binding ◽  
Total Lipids ◽  
Function Relationship ◽  
Relationship Of

The composition-function relationship of HDL particles and its effects on the mechanisms driving coronary heart disease (CHD) is poorly understood. We tested the hypothesis that the functionality of HDL particles is significantly influenced by their lipid composition. Using a novel 3D-separation method, we isolated five different-sized HDL subpopulations from CHD patients who had low preβ-1 functionality (low-F) (ABCA1-dependent cholesterol-efflux normalized for preβ-1 concentration) and controls who had either low-F or high preβ-1 functionality (high-F). Molecular numbers of apoA-I, apoA-II, and eight major lipid classes were determined in each subpopulation by LC-MS. The average number of lipid molecules decreased from 422 in the large spherical α-1 particles to 57 in the small discoid preβ-1 particles. With decreasing particle size, the relative concentration of free cholesterol (FC) decreased in α-mobility but not in preβ-1 particles. Preβ-1 particles contained more lipids than predicted; 30% of which were neutral lipids (cholesteryl ester and triglyceride), indicating that these particles were mainly remodeled from larger particles not newly synthesized. There were significant correlations between HDL-particle functionality and the concentrations of several lipids. Unexpectedly, the phospholipid:FC ratio was significantly correlated with large-HDL-particle functionality but not with preβ-1 functionality. There was significant positive correlation between particle functionality and total lipids in high-F controls, indicating that the lipid-binding capacity of apoA-I plays a major role in the cholesterol efflux capacity of HDL particles. Functionality and lipid composition of HDL particles are significantly correlated and probably both are influenced by the lipid-binding capacity of apoA-I.

scholarly journals Structure-Function Analysis of Immunity Proteins of Pediocin-Like Bacteriocins: C-Terminal Parts of Immunity Proteins Are Involved in Specific Recognition of Cognate Bacteriocins

2004 ◽  
Vol 70 (5) ◽  
pp. 2647-2652 ◽  
Author(s):  
Line Johnsen ◽  
Gunnar Fimland ◽  
Dimitris Mantzilas ◽  
Jon Nissen-Meyer
Keyword(s):  
Structure Function ◽  
Function Analysis ◽  
Cd Spectroscopy ◽  
Aqueous Environment ◽  
Specific Recognition ◽  
Function Relationship ◽  
Enterocin A ◽  
Relationship Of ◽  
High Degree ◽  
Strain Dependent

ABSTRACT The immunity proteins of pediocin-like bacteriocins show a high degree of specificity with respect to the pediocin-like bacteriocin they recognize and confer immunity to. The aim of this study was to identify regions of the immunity proteins that are involved in this specific recognition. Six different hybrid immunity proteins were constructed from three different pediocin-like bacteriocin immunity proteins that have similar sequences but confer resistance to different bacteriocins. These hybrid immunity proteins were then tested for their ability to confer immunity to various pediocin-like bacteriocins. The specificities of the hybrid immunity proteins proved to be similar to those of the immunity proteins from which the C-terminal halves were derived, thus revealing that the C-terminal half of immunity proteins for pediocin-like bacteriocins contains a domain that is involved in specific recognition of the bacteriocins they confer immunity to. Moreover, the results also revealed that the effectiveness of an immunity protein is strain dependent and that its functionality thus depends in part on interplay with strain-dependent factors. To further investigate the structure-function relationship of these immunity proteins, the enterocin A and leucocin A immunity proteins (EntA-im and LeuA-im) were purified to homogeneity and structurally analyzed under various conditions by Circular dichroism (CD) spectroscopy. The results revealed that both immunity proteins are α-helical and well structured in an aqueous environment, the denaturing temperature being 78.5°C for EntA-im and 58.0°C for LeuA-im. The CD spectra also revealed that there was no further increase in the structuring or α-helical content when the immunity proteins were exposed to dodecylphosphocholine micelles or dioleoyl-l-α-phosphatidyl-dl-glycerol (DOPG) liposomes, indicating that the immunity proteins, in contrast to the bacteriocins, do not interact extensively with membranes. They may nevertheless be loosely associated with the membrane, possibly as peripheral membrane proteins, thus enabling them to interact with their cognate bacteriocin.

Structure–property–function relationship of fluorescent conjugated microporous polymers

2021 ◽  
Author(s):  
M. G. Monika Bai ◽  
H. Vignesh Babu ◽  
V. Lakshmi ◽  
M. Rajeswara Rao
Keyword(s):  
Long Range ◽  
Structure Property ◽  
Porous Organic Polymers ◽  
Aggregation Induced Emission ◽  
Microporous Polymers ◽  
Exciton Migration ◽  
Wide Range ◽  
Function Relationship ◽  
Relationship Of ◽  
Conjugated Microporous Polymers

Fluorescent porous organic polymers are a unique class of materials owing to their strong aggregation induced emission, long range exciton migration and permanent porosity, thus envisioned to possess a wide range of applications (sensing, OLEDs).

Morphology-Function Relationship of Thermoelectric Nanocomposite Films from PEDOT:PSS with Silicon Nanoparticles

2017 ◽  
Vol 3 (8) ◽  
pp. 1700181 ◽  
Author(s):  
Nitin Saxena ◽  
Mihael Čorić ◽  
Anton Greppmair ◽  
Jan Wernecke ◽  
Mika Pflüger ◽  
...  
Keyword(s):  
Silicon Nanoparticles ◽  
Nanocomposite Films ◽  
Function Relationship ◽  
Relationship Of

scholarly journals High-resolution single-cell 3D-models of chromatin ensembles during Drosophila embryogenesis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Qiu Sun ◽  
Alan Perez-Rathke ◽  
Daniel M. Czajkowsky ◽  
Zhifeng Shao ◽  
Jie Liang
Keyword(s):  
High Resolution ◽  
Single Cell ◽  
3D Models ◽  
Computational Method ◽  
Midblastula Transition ◽  
Genome Wide ◽  
Large Ensembles ◽  
Chromatin Folding ◽  
Function Relationship ◽  
Relationship Of

AbstractSingle-cell chromatin studies provide insights into how chromatin structure relates to functions of individual cells. However, balancing high-resolution and genome wide-coverage remains challenging. We describe a computational method for the reconstruction of large 3D-ensembles of single-cell (sc) chromatin conformations from population Hi-C that we apply to study embryogenesis in Drosophila. With minimal assumptions of physical properties and without adjustable parameters, our method generates large ensembles of chromatin conformations via deep-sampling. Our method identifies specific interactions, which constitute 5–6% of Hi-C frequencies, but surprisingly are sufficient to drive chromatin folding, giving rise to the observed Hi-C patterns. Modeled sc-chromatins quantify chromatin heterogeneity, revealing significant changes during embryogenesis. Furthermore, >50% of modeled sc-chromatin maintain topologically associating domains (TADs) in early embryos, when no population TADs are perceptible. Domain boundaries become fixated during development, with strong preference at binding-sites of insulator-complexes upon the midblastula transition. Overall, high-resolution 3D-ensembles of sc-chromatin conformations enable further in-depth interpretation of population Hi-C, improving understanding of the structure-function relationship of genome organization.

Dietary Selenium or Zinc Supplementation Restores Brain Lipid Composition and Membrane Fluidity in Protein-Undernourished Rats

2016 ◽  
Vol 38 (6) ◽  
pp. 397-406
Author(s):  
Olusegun L. Adebayo ◽  
Bamidele A. Salau ◽  
Rajat Sandhir ◽  
Gbenga A. Adenuga
Keyword(s):  
Membrane Fluidity ◽  
Lipid Composition ◽  
Zinc Supplementation ◽  
Protective Role ◽  
Membrane Lipid ◽  
Limited Information ◽  
Total Lipids ◽  
Major Focus ◽  
Membrane Lipid Composition

Studies have shown that protein undernutrition (PU) modifies the membrane lipid composition in the intestine and liver, as well as in plasma and other areas. However, there is limited information on the effect of PU on synaptosomal membrane lipid composition and fluidity and the protective role of selenium (Se) and zinc (Zn), which is a major focus of the present study. For 10 weeks, rats were fed diets containing 16% casein, which constituted the adequate protein diet, or 5% casein, representing the PU diet. The animals were supplemented with Se and Zn at a concentration of 0.15 and 227 mg L-1, respectively, in drinking water for 3 weeks. The results showed a significant increase in total lipids, glycolipids, triglycerides, cholesterol, and the cholesterol/phospholipid (Chol/PL) ratio, and a significant reduction in phospholipids and membrane fluidity. Se and Zn supplementation to PU rats, however, significantly lowered total lipids, glycolipids, triglycerides, cholesterol, and the Chol/PL ratio, while phospholipids and membrane fluidity were significantly restored. It is concluded that a perturbed lipid composition induced by PU affects the membrane structure and fluidity, which in turn influences membrane functions. The study suggests that Se and Zn supplementation might be beneficial in restoring the lipid dyshomeostasis associated with PU.

Role of aromatic residues in the structure-function relationship of .alpha.-bungarotoxin

Biochemistry ◽  
1982 ◽  
Vol 21 (11) ◽  
pp. 2592-2600 ◽  
Author(s):  
Yee Hsiung Chen ◽  
Jang Chyi Tai ◽  
Wan Jen Huang ◽  
Ming Zong Lai ◽  
Mien Chie Hung ◽  
...  
Keyword(s):  
Structure Function ◽  
Aromatic Residues ◽  
Structure Function Relationship ◽  
Function Relationship ◽  
Alpha Bungarotoxin ◽  
Relationship Of
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