OmpF porin from Yersinia ruckeri as pathogenic factor: Surface antigenic sites and biological properties

2021 ◽  
Vol 150 ◽  
pp. 104694
Author(s):  
Olga Portnyagina ◽  
Dmitry Chistyulin ◽  
Sergey Dyshlovoy ◽  
Viktoriya Davidova ◽  
Valentina Khomenko ◽  
...  
Keyword(s):  
Biological Properties ◽  
Pathogenic Factor ◽  
Yersinia Ruckeri ◽  
Ompf Porin ◽  
Antigenic Sites

Peculiarities of thermal denaturation of OmpF porin from Yersinia ruckeri

2017 ◽  
Vol 13 (9) ◽  
pp. 1854-1862 ◽  
Author(s):  
Olga D. Novikova ◽  
Dmitry K. Chistyulin ◽  
Valentina A. Khomenko ◽  
Evgeny V. Sidorin ◽  
Natalya Yu. Kim ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Thermal Denaturation ◽  
Water Soluble ◽  
Yersinia Ruckeri ◽  
Multidomain Proteins ◽  
Multistage Process ◽  
Ompf Porin ◽  
Irreversible Denaturation ◽  
Detergent Solutions

Irreversible denaturation of membrane proteins in detergent solutions is similar to unfolding of water-soluble multidomain proteins and represents a complex, multistage process.

scholarly journals Topography of N-CAM structural and functional determinants. II. Placement of monoclonal antibody epitopes.

1986 ◽  
Vol 103 (5) ◽  
pp. 1729-1737 ◽  
Author(s):  
A L Frelinger ◽  
U Rutishauser
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Cell Membrane ◽  
Biological Properties ◽  
Peptide Chain ◽  
Functional Domains ◽  
Peptide Fragments ◽  
Antigenic Sites ◽  
Cell Biol ◽  
Antibody Epitopes

The accompanying report (Watanabe, M., A. L. Frelinger III, and U. Rutishauser, 1986, J. Cell Biol., 103:1721-1727) describes a set of monoclonal antibodies (mAbs) directed against N-CAM epitopes representing the known major structural and functional domains of the molecule. In this study, we have generated and separated a variety of peptide fragments from N-CAM, and then used their size and reactivity with each antibody to position the antigenic sites along the peptide chain. This epitope map, together with the biological properties of the antibodies and previous studies on N-CAM, have been used to construct a topographical model for the molecule in the cell membrane.

scholarly journals Phosphatidylcholine (lecithin) stimulating effect on pathogenic properties of pneumococcus

2014 ◽  
Vol 21 (1) ◽  
pp. 48-51
Author(s):  
A. S. Kvetnaya ◽  
L. I. Zhelezova
Keyword(s):  
Cell Wall ◽  
Hemolytic Activity ◽  
Teichoic Acid ◽  
Biological Properties ◽  
Pathogenic Factor ◽  
C Reactive Protein ◽  
Capsule Formation ◽  
Reactive Protein ◽  
Growth Stimulant

The authors have studied the effect of phosphatidylcholine (lecithin) - a derivative of choline - on the biological properties of streptococus pneumonia. The concentration of lecithin 0.01 g/l in a simple nutrient broth has a stimulating effect on proliferation, on in vitro stabilization of the population, and on pathogenic properties of the pneumococcus. Four - five times passaging of the strains on this medium (as opposed to the commonly used 20 % serum broth) retained the species and the typical properties of pneumococcus, but led to increased capsule formation, increased virulence and expressed β-hemolytic activity. These results suggest that phosphatidylcholine (lecithin), as the main supplier of pneumococcus growth stimulant - choline, has an expressing impact on the capsule formation - the main pathogenic factor, and on the substance of P-teichoic acid in the cell wall of pneumococcus that specifically interacts with the C-reactive protein.

scholarly journals An Abnormally High Closing Potential of the OMPF Porin Channel from Yersinia Ruckeri: The Role of Charged Residues and Intramolecular Bonds

Acta Naturae ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 89-98
Author(s):  
D. K. Chistyulin ◽  
O. D. Novikova ◽  
E. A. Zelepuga ◽  
V. A. Khomenko ◽  
G. N. Likhatskaya ◽  
...  
Keyword(s):  
Lipid Membranes ◽  
Gram Negative Bacteria ◽  
Amino Acid Residues ◽  
Yersinia Ruckeri ◽  
Ompf Porin ◽  
E Coli ◽  
Total Conductance ◽  
Voltage Dependent ◽  
Acidic Conditions

Electrophysiological experiments on bilayer lipid membranes showed that the isolated outer membrane major porin of Yersinia ruckeri (YrOmpF) exhibits activity typical of porins from Gram-negative bacteria, forming channels with a mean conductance of 230 pS (in 0.1 M KCl) and slight asymmetry with respect to the applied voltage. Under acidic conditions (up to pH = 3.0), there was no significant decrease in the total conductance of the YrOmpF channel reconstituted into the bilayer. The studied channel significantly differed from the porins of other bacteria by high values of its critical closing potential (Vc): Vc = 232 mV at pH = 7.0 and Vc = 164 mV at pH = 5.0. A theoretical model of the YrOmpF spatial structure was used for the analysis of the charge distribution in the mouth and inside the channel to explain these properties and quantitatively assess the bonds between the amino acid residues in the L3 loop and on the inner wall of the barrel. The parameters of YrOmpF were compared with those of the classical OmpF porin from E. coli. The results of electrophysiological experiments and theoretical analysis are discussed in terms of the mechanism for voltage-dependent closing of porin channels.

Immunogold labeling of Pneumocystis carinii for Electron microscopy

1991 ◽  
Vol 49 ◽  
pp. 270-271
Author(s):  
Michael P. Goheen ◽  
Marilyn S. Bartlett ◽  
James W. Smith
Keyword(s):  
Electron Microscopy ◽  
Pneumocystis Carinii ◽  
Severe Pneumonia ◽  
Culture Fluid ◽  
Immunogold Labeling ◽  
Antigenic Sites ◽  
Transmission Electron ◽  
Response To Chemotherapy ◽  
Acquired Immunodeficiency ◽  
Immunodeficiency Syndrome

Studies of the biology of Pneumocystis carinii (PC) are of increasing importance because this extracellular pathogen is a frequent source of severe pneumonia in patients with acquired immunodeficiency syndrome (AIDS) and is a leading cause of mortality in these patients. Immunoelectron microscopic localization of antigenic sites on the surface of PC would improve the understanding of these sites and their role in pathenogenisis of the disease and response to chemotherapy. The purpose of this study was to develop a methodology for visualizing immunoreactive sites on PC with transmission electron microscopy (TEM) using immunogold labeled probes.Trophozoites of PC were added to spinner flask cultures and allowed to grow for 7 days, then aliquots of tissue culture fluid were centrifuged at 12,000 RPM for 30 sec. Pellets of organisims were fixed in either 1% glutaraldehyde, 0.1% glutaraldehyde-4% paraformaldehyde, or 4% paraformaldehyde for 4h. All fixatives were buffered with 0.1M Na cacodylate and the pH adjusted to 7.1. After fixation the pellets were rinsed in 0.1M Na cacodylate (3X), dehydrated with ethanol, and immersed in a 1:1 mixture of 95% ethanol and LR White resin.

Three Dimensional structure and organization of diploid chromosomes by optical section microscopy

1987 ◽  
Vol 45 ◽  
pp. 633-635
Author(s):  
David A. Agard ◽  
Yasushi Hiraoka ◽  
John W. Sedat
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Developmental State ◽  
Mitotic Cell ◽  
Biological Properties ◽  
Dimensional Structure ◽  
Specific Gene ◽  
Three Dimensional Structure ◽  
Complementary Techniques ◽  
Dynamic Structures

In an effort to understand the complex relationship between structure and biological function within the nucleus, we have embarked on a program to examine the three-dimensional structure and organization of Drosophila melanogaster embryonic chromosomes. Our overall goal is to determine how DNA and proteins are organized into complex and highly dynamic structures (chromosomes) and how these chromosomes are arranged in three dimensional space within the cell nucleus. Futher, we hope to be able to correlate structual data with such fundamental biological properties as stage in the mitotic cell cycle, developmental state and transcription at specific gene loci.Towards this end, we have been developing methodologies for the three-dimensional analysis of non-crystalline biological specimens using optical and electron microscopy. We feel that the combination of these two complementary techniques allows an unprecedented look at the structural organization of cellular components ranging in size from 100A to 100 microns.

The Application of Protein A-Gold Immunocytochemistry to Studies of Protein Secretion

1985 ◽  
Vol 43 ◽  
pp. 426-429
Author(s):  
George H. Herbener ◽  
Antonio Nanci ◽  
Moise Bendayan
Keyword(s):  
Tissue Section ◽  
Colloidal Gold ◽  
Unit Area ◽  
Protein A ◽  
Extracellular Proteins ◽  
Gold Complex ◽  
Second Step ◽  
Igg Antibodies ◽  
Tissue Sections ◽  
Antigenic Sites

Protein A-gold immunocytochemistry is a two-step, post-embedding labeling procedure which may be applied to tissue sections to localize intra- and extracellular proteins. The key requisite for immunocytochemistry is the availability of the appropriate antibody to react in an immune response with the antigenic sites on the protein of interest. During the second step, protein A-gold complex is reacted with the antibody. This is a non- specific reaction in that protein A will combine with most IgG antibodies. The ‘label’ visualized in the electron microscope is colloidal gold. Since labeling is restricted to the surface of the tissue section and since colloidal gold is particulate, labeling density, i.e., the number of gold particles per unit area of tissue section, may be quantitated with ease and accuracy.

Membrane–cytoskeleton interactions in cholesterol-dependent domain formation

2015 ◽  
Vol 57 ◽  
pp. 177-187 ◽  
Author(s):  
Jennifer N. Byrum ◽  
William Rodgers
Keyword(s):  
Biological Properties ◽  
Membrane Rafts ◽  
Membrane Domains ◽  
Biological Functions ◽  
Membrane Cytoskeleton ◽  
Heterogeneous Structures ◽  
Integral Role ◽  
Model Cell ◽  
Actomyosin Cytoskeleton ◽  
Dependent Domain

Since the inception of the fluid mosaic model, cell membranes have come to be recognized as heterogeneous structures composed of discrete protein and lipid domains of various dimensions and biological functions. The structural and biological properties of membrane domains are represented by CDM (cholesterol-dependent membrane) domains, frequently referred to as membrane ‘rafts’. Biological functions attributed to CDMs include signal transduction. In T-cells, CDMs function in the regulation of the Src family kinase Lck (p56lck) by sequestering Lck from its activator CD45. Despite evidence of discrete CDM domains with specific functions, the mechanism by which they form and are maintained within a fluid and dynamic lipid bilayer is not completely understood. In the present chapter, we discuss recent advances showing that the actomyosin cytoskeleton has an integral role in the formation of CDM domains. Using Lck as a model, we also discuss recent findings regarding cytoskeleton-dependent CDM domain functions in protein regulation.

Biological properties of the berries of five Juniperus species in Juniperus section from Turkey

Planta Medica ◽  
2011 ◽  
Vol 77 (12) ◽  
Author(s):  
N Miceli ◽  
MF Taviano ◽  
A Trovato ◽  
R De Pasquale ◽  
P Maimone ◽  
...  
Keyword(s):  
Biological Properties
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