scholarly journals INFLUENCE OF ERYTHROCYTE MEMBRANE COMPONENTS ON MALARIA MEROZOITE INVASION

1973 ◽  
Vol 138 (6) ◽  
pp. 1597-1601 ◽  
Author(s):  
Louis H. Miller ◽  
James A. Dvorak ◽  
Tsugiye Shiroishi ◽  
John R. Durocher
Keyword(s):  
Erythrocyte Membrane ◽  
Membrane Structure ◽  
Surface Protein ◽  
Receptor Site ◽  
Human Erythrocytes ◽  
Merozoite Invasion ◽  
Membrane Components

Chymotrypsin- and Pronase-treated human erythrocytes were refractory to invasion by P. knowlesi merozoites; invasion was not inhibited by trypsin or neurammidase treatment. These data implicate a surface protein other than sialoglycoprotein as the receptor site for merozoites. Invasion of rhesus erythrocytes was unaffected by pretreatment with these enzymes. Differences in membrane structure of erythrocytes from various species may explain the absence of an enzyme effect on rhesus erythrocytes.

scholarly journals Human erythrocytes adhering to schistosomula of Schistosoma mansoni lyse and fail to transfer membrane components to the parasite.

1985 ◽  
Vol 101 (1) ◽  
pp. 158-166 ◽  
Author(s):  
J P Caulfield ◽  
C M Cianci
Keyword(s):  
Schistosoma Mansoni ◽  
Erythrocyte Membrane ◽  
Plasma Membranes ◽  
Freeze Fracture ◽  
Human Erythrocytes ◽  
Transmission Microscopy ◽  
Carbocyanine Dyes ◽  
Host Membrane ◽  
Membrane Components ◽  
20 Nm

We studied the adherence of human erythrocytes to larvae of the intravascular parasite Schistosoma mansoni by transmission microscopy, freeze fracture, and fluorescence techniques. In addition, we used the adherent cells to investigate the problem of host antigen acquisition. Schistosomula were cultured for from 24 to 48 h after transformation in order to clear the remnants of the cercarial glycocalyx. In some cases, the worms were preincubated with wheat germ agglutinin to promote adherence of the erythrocytes. The results were similar with and without the lectin except that more cells attached to the lectin-coated parasites. Erythrocytes adhered within a few hours and, unlike neutrophils, did not fuse with the parasite. A layer of 10-20-nm electron dense material separated the outer leaflets of the tegumental and plasma membranes. In addition, many deformed and lysed cells were seen on the parasite surface. The ability of the worm to acquire erythrocyte membrane constituents was tested with carbocyanine dyes, fluorescein covalently conjugated to glycophorin, monoclonal antibodies against B and H blood group glycolipids, and rabbit alpha-human erythrocyte IgG. In summary, glycophorin, erythrocyte proteins, and glycolipids were not transferred to the parasite membrane within 48 h. Carbocyanine dyes were rapidly transferred to the parasite with or without lectin preincubation. Thus, the dye in the worm membrane came from both adherent and nonadherent cells. These studies suggest that, in the absence of membrane fusion, the parasite may acquire some lipid molecules similar in structure to host membrane glycolipids by simple transfer through the medium but that B and H glycolipids and erythrocyte membrane proteins are not transferred from adhering cells to the worm.

scholarly journals Enhancing Pervaporation Membrane Selectivity by Incorporating Star Macromolecules Modified with Ionic Liquid for Intensification of Lactic Acid Dehydration

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1811
Author(s):  
Valeriia Rostovtseva ◽  
Alexandra Pulyalina ◽  
Roman Dubovenko ◽  
Ilya Faykov ◽  
Kseniya Subbotina ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Lactic Acid ◽  
Polymer Matrix ◽  
Separation Factor ◽  
Membrane Structure ◽  
High Performance ◽  
Separation Efficiency ◽  
Pharmaceutical Chemical ◽  
Permeate Flux ◽  
Membrane Components

Modification of polymer matrix by hybrid fillers is a promising way to produce membranes with excellent separation efficiency due to variations in membrane structure. High-performance membranes for the pervaporation dehydration were produced by modifying poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) to facilitate lactic acid purification. Ionic liquid (IL), heteroarm star macromolecules (HSM), and their combination (IL:HSM) were employed as additives to the polymer matrix. The composition and structure of hybrid membranes were characterized by X-ray diffraction and FTIR spectroscopy. Scanning electron microscopy was used to investigate the membranes surface and cross-section morphology. It was established that the inclusion of modifiers in the polymer matrix leads to the change of membrane structure. The influence of IL:HSM was also studied via sorption experiments and pervaporation of water‒lactic acid mixtures. Lactic acid is an essential compound in many industries, including food, pharmaceutical, chemical, while the recovering and purifying account for approximately 50% of its production cost. It was found that the membranes selectively remove water from the feed. Quantum mechanical calculations determine the favorable interactions between various membrane components and the liquid mixture. With IL:HSM addition, the separation factor and performance in lactic acid dehydration were improved compared with pure polymer membrane. The best performance was found for (HSM: IL)-PPO/UPM composite membrane, where the permeate flux and the separation factor of about 0.06 kg m−2 h−1 and 749, respectively, were obtained. The research results demonstrated that ionic liquids in combination with star macromolecules for membrane modification could be a promising approach for membrane design.

scholarly journals The Central Role of cAMP in Regulating Plasmodium falciparum Merozoite Invasion of Human Erythrocytes

2014 ◽  
Vol 10 (12) ◽  
pp. e1004520 ◽  
Author(s):  
Amrita Dawn ◽  
Shailja Singh ◽  
Kunal R. More ◽  
Faiza Amber Siddiqui ◽  
Niseema Pachikara ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Human Erythrocytes ◽  
Merozoite Invasion ◽  
Falciparum Merozoite

Adhesion of normal and Plasmodium falciparum ring–infected erythrocytes to endothelial cells and the placenta involves the rhoptry-derived ring surface protein-2

Blood ◽  
2003 ◽  
Vol 101 (12) ◽  
pp. 5025-5032 ◽  
Author(s):  
Jean-Bernard Lekana Douki ◽  
Yvon Sterkers ◽  
Catherine Lépolard ◽  
Boubacar Traoré ◽  
Fabio T. M. Costa ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Plasmodium Falciparum ◽  
Erythrocyte Membrane ◽  
Time Course ◽  
Surface Protein ◽  
Blood Stage ◽  
Current View ◽  
Ring Stage ◽  
Surface Fluorescence ◽  
Falciparum Erythrocyte Membrane Protein

Abstract Recent findings have challenged the current view of Plasmodium falciparum (P falciparum) blood-stage biology by demonstrating the cytoadhesion of early ring-stage–infected erythrocytes (rIEs) to host endothelial cells and placental syncytiotrophoblasts. The adhesion of rIEs was observed only in parasites that bind to the placenta via chondroitin sulfate A (CSA). In this work, a panel of mouse monoclonal antibodies (mAbs) that specifically inhibit cytoadhesion of rIEs but not of mature IEs was generated The previously described ring surface protein 2 (RSP-2), a 42-kDa protein, was identified as the target of the ring-stage–specific mAbs. Time course surface fluorescence experiments revealed a short overlap (approximately 4 hours) of expression between RSP-2 and P falciparum erythrocyte membrane protein 1 (PfEMP1). Their consecutive expression enables IEs to adhere to endothelial cells during the entire blood-stage cycle. During this study, a new phenotype was detected in parasite cultures, the adhesion of normal erythrocytes (nEs) to endothelial cells. All adherent nEs were coated with RSP-2. Immunolocalization studies show that RSP-2 is a rhoptry-derived protein that is discharged onto the erythrocyte membrane during contact with merozoites. Our results identify RSP-2 as a key molecule in sequestration of young blood-stage forms and nEs to endothelial cells.

ANTIOXIDANTS AS INHIBITORS OF LINOLEATE OXIDATION CATALYZED BY PLANT LIPOXIDASE AND BY HEMOLYZATES OF HUMAN ERYTHROCYTES

1955 ◽  
Vol 33 (1) ◽  
pp. 773-779 ◽  
Author(s):  
H. Bruce Collier ◽  
Sheila C. McRae
Keyword(s):  
Fatty Acids ◽  
Catalytic Activity ◽  
Erythrocyte Membrane ◽  
Unsaturated Fatty Acids ◽  
Human Erythrocytes ◽  
Catalytic Action ◽  
Time Activity ◽  
Linoleate Oxidation

Hemolyzates of human erythrocytes catalyzed the oxidation of linoleate at pH 7 but not at pH 9. Hence the erythrocytes contained no lipoxidase and the catalytic action was probably due to hemoglobin. However, the time-activity curves for hemolyzates and for crystalline hemoglobin were not identical in shape. The oxidation of linoleate at pH 7 by plant lipoxidase was powerfully inhibited by phenothiazine and by phenylhydrazine. These compounds, and also α-tocopherol and α-naphthol, inhibited the catalytic activity of hemolyzates and of crystalline hemoglobin. It is probable that phenothiazine and phenylhydrazine act as antioxidants in these systems. Antioxidants in vivo may possibly play a role in protecting the unsaturated fatty acids of the erythrocyte membrane from oxidation catalyzed by hemoglobin.

Protein–protein interaction studies reveal the Plasmodium falciparum merozoite surface protein-1 region involved in a complex formation that binds to human erythrocytes

2018 ◽  
Vol 475 (6) ◽  
pp. 1197-1209 ◽  
Author(s):  
Gourab Paul ◽  
Arunaditya Deshmukh ◽  
Bishwanath Kumar Chourasia ◽  
Md Kalamuddin ◽  
Ashutosh Panda ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Recombinant Proteins ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Human Erythrocytes ◽  
Proteolytic Processing ◽  
Protein Protein Interaction ◽  
Falciparum Merozoite ◽  
Vaccine Candidate Antigen ◽  
Serological Studies

Plasmodium falciparum merozoite surface protein (PfMSP) 1 has been studied extensively as a vaccine candidate antigen. PfMSP-1 undergoes proteolytic processing into four major products, such as p83, p30, p38, and p42, that are associated in the form of non-covalent complex(s) with other MSPs. To delineate MSP1 regions involved in the interaction with other MSPs, here we expressed recombinant proteins (PfMSP-165) encompassing part of p38 and p42 regions and PfMSP-119. PfMSP-165 interacted strongly with PfMSP-3, PfMSP-6, PfMSP-7, and PfMSP-9, whereas PfMSP-119 did not interact with any of these proteins. Since MSP-1 complex binds human erythrocytes, we examined the ability of these proteins to bind human erythrocyte. Among the proteins of MSP-1 complex, PfMSP-6 and PfMSP-9 bound to human erythrocytes. Serological studies showed that PfMSP-165 was frequently recognized by sera from malaria endemic regions, whereas this was not the case for PfMSP-119. In contrast, antibodies against PfMSP-119 showed much higher inhibition of merozoite invasion compared with antibodies against the larger PfMSP-165 fragment. Importantly, anti-PfMSP-119 antibodies recognized both recombinant proteins, PfMSP-119 and PfMSP-165; however, anti-PfMSP-165 antibody failed to recognize the PfMSP-119 protein. Taken together, these results demonstrate that PfMSP-1 sequences upstream of the 19 kDa C-terminal region are involved in molecular interactions with other MSPs, and these sequences may probably serve as a smoke screen to evade antibody response to the membrane-bound C-terminal 19 kDa region.

scholarly journals Calcium distribution within human erythrocytes

Blood ◽  
1980 ◽  
Vol 56 (4) ◽  
pp. 667-676 ◽  
Author(s):  
SL Schrier ◽  
M Johnson ◽  
I Junga ◽  
J Krueger
Keyword(s):  
Erythrocyte Membrane ◽  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
Human Erythrocytes ◽  
Calcium Distribution ◽  
Normal Controls

Abstract In order to study 45Ca distribution within erythrocytes, a method was devised that had minimal deleterious effects on the treated erythrocytes. It was observed that newly introduced 45Ca was predominantly recoverable from the cytosol and exchanged relatively slowly with membrane-associated Ca. Younger erythrocytes appeared to have relatively more 45Ca in membrane-associated sites. Erythrocytes from patients with sickle cell anemia had significantly more 45Ca in membrane-associated sites than did normal controls or patients with reticuloctosis due to a variety of disorders. There are theoretical reasons for considering the possibility that the distribution of 45Ca between cytosol and membrane-associated sites could modulate some of the properties of the erythrocyte membrane.

scholarly journals Identification of phagocytosis-associated surface proteins of macrophages by two-dimensional gel electrophoresis.

1982 ◽  
Vol 92 (2) ◽  
pp. 283-288 ◽  
Author(s):  
F D Howard ◽  
H R Petty ◽  
H M McConnell
Keyword(s):  
Cell Surface ◽  
Gel Electrophoresis ◽  
Protein Composition ◽  
Surface Protein ◽  
Surface Proteins ◽  
Two Dimensional ◽  
Cell Surface Protein ◽  
Two Dimensional Gel Electrophoresis ◽  
Reducing Conditions ◽  
Membrane Components

Two-dimensional PAGE (P. Z. O'Farrell, H. M. Goodman, and P. H. O'Farrell. 1977. Cell. 12:1133-1142) has been employed to assess the effects of antibody-dependent phagocytosis on the cell surface protein composition of RAW264 macrophages. Unilamellar phospholipid vesicles containing 1% dinitrophenyl-aminocaproyl-phosphatidylethanolamine (DNP-cap-PE) were used as the target particle. Macrophages were exposed to anti-DNP antibody alone, vesicles alone, or vesicles in the presence of antibody for 1 h at 37 degrees C. Cell surface proteins were then labeled by lactoperoxidase-catalyzed radioiodination at 4 degrees C. After detergent solubilization, membrane proteins were analyzed by two-dimensional gel electrophoresis. The resulting pattern of spots was compared to that of standard proteins. We have identified several surface proteins, not apparently associated with the phagocytic process, which are present either in a multichain structure or in several discretely charged forms. After phagocytosis, we have observed the appearance of two proteins of 45 and 50 kdaltons in nonreducing gels. In addition, we have noted the disappearance of a 140-kdalton protein in gels run under reducing conditions. These alterations would not be detected in the conventional one-dimensional gel electrophoresis. This evidence shows that phagocytosis leads to a modification of cell surface protein composition. Our results support the concept of specific enrichment and depletion of membrane components during antibody-dependent phagocytosis.

A study of Erythrocyte Membrane Proteins and Urinary Polypeptides in Conga Drumming Haemoglobinuria

1985 ◽  
Vol 69 (1) ◽  
pp. 105-108 ◽  
Author(s):  
Richard D. Levy ◽  
Ali A. Khaleeli ◽  
Beatrice L. Griffiths ◽  
Yvonne H. Edwards
Keyword(s):  
Membrane Proteins ◽  
Carbonic Anhydrase ◽  
Erythrocyte Membrane ◽  
Acute Phase ◽  
Protein Staining ◽  
Membrane Components ◽  
Erythrocyte Membrane Proteins ◽  
Erythrocyte Carbonic Anhydrase

1. The erythrocyte membrane proteins and glycoproteins and urinary polypeptides have been examined in a patient exhibiting intermittent pigmenturia associated with conga drumming. 2. Significant excretion of haemoglobin, albumin and probably erythrocyte carbonic anhydrase but not myoglobin occurred during the acute phase of the conga drumming-induced pigmenturia. This usually ceased within 24-48 h. 3. We found no evidence of aberrant erythrocyte membrane components on electrophoresis with either protein staining or a range of 125I-labelled lectins used for detection.

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