scholarly journals Secretion of a malarial histidine-rich protein (Pf HRP II) from Plasmodium falciparum-infected erythrocytes.

1986 ◽  
Vol 103 (4) ◽  
pp. 1269-1277 ◽  
Author(s):  
R J Howard ◽  
S Uni ◽  
M Aikawa ◽  
S B Aley ◽  
J H Leech ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Plasmodium Falciparum ◽  
Water Soluble ◽  
Intracellular Growth ◽  
Trophozoite Stage ◽  
Cell Compartments ◽  
Host Cell Cytoplasm ◽  
Water Soluble Protein ◽  
Major Species ◽  
Low Levels

Plasmodium falciparum-infected erythrocytes (IRBCs) synthesize several histidine-rich proteins (HRPs) that accumulate high levels of [3H]histidine but very low levels of amino acids such as [3H]isoleucine or [35S]methionine. We prepared a monoclonal antibody which reacts specifically with one of these HRPs (Pf HRP II) and studied the location and synthesis of this protein during the parasite's intracellular growth. With the knob-positive Malayan Camp strain of P. falciparum, the monoclonal antibody identified a multiplet of protein bands with major species at Mr 72,000 and 69,000. Pf HRP II synthesis began with immature parasites (rings) and continued through the trophozoite stage. The Mr 72,000 band of Pf HRP II, but not the faster moving bands of the multiplet, was recovered as a water-soluble protein from the culture supernatant of intact IRBCs. Approximately 50% of the total [3H]histidine radioactivity incorporated into the Mr 72,000 band was extracellular between 2 and 24 h of culture. Immunofluorescence and cryothin-section immunoelectron microscopy localized Pf HRP II to several cell compartments including the parasite cytoplasm, as concentrated "packets" in the host erythrocyte cytoplasm and at the IRBC membrane. Our results provide evidence for an intracellular route of transport for a secreted malarial protein from the parasite through several membranes and the host cell cytoplasm.

scholarly journals Absence of one component of spectrin adenosine triphosphatase in hereditary spherocytosis

Blood ◽  
1975 ◽  
Vol 46 (6) ◽  
pp. 945-954 ◽  
Author(s):  
FH Kirkpatrick ◽  
GM Woods ◽  
PL La Celle
Keyword(s):  
Atpase Activity ◽  
Soluble Protein ◽  
Adenosine Triphosphatase ◽  
Hereditary Spherocytosis ◽  
Water Soluble ◽  
Water Soluble Protein ◽  
Normal Water ◽  
Calcium And Magnesium ◽  
Low Levels ◽  
Increased Activity

Abstract The stimulation by calcium and magnesium of ATPase activity of isolated ghosts, of water-soluble protein (spectrin), and of residual vesicles, derived from normal erythrocytes and from hereditary spherocytes (H.S.), has been measured. The ATPase activity found in normal water- soluble protein (WSP) at low levels of calcium (0.1–2.0 mM) is essentially absent in H.S. water-soluble protein, but the ATPase activity with magnesium and with high levels of calcium (60-100 mM) is the same in H.S. and normal WSP. Compared to normal, H.S. ghosts have increased Mg2+-stimulated activity. This increased activity is retained by the sedimentable vesicles (“residue”) after extraction of the ghosts with 0.025 mM EDTA. The Ca2+, Mg2+-ATPase associated with the calcium pump is not significantly different in H.S.

scholarly journals Secretion of Plasmodium falciparum rhoptry protein into the plasma membrane of host erythrocytes.

1988 ◽  
Vol 106 (5) ◽  
pp. 1507-1513 ◽  
Author(s):  
T Y Sam-Yellowe ◽  
H Shio ◽  
M E Perkins
Keyword(s):  
Monoclonal Antibody ◽  
Plasmodium Falciparum ◽  
Plasma Membrane ◽  
Final Stage ◽  
Trophozoite Stage ◽  
Parasite Invasion ◽  
Disulfide Linkage ◽  
The Matrix ◽  
Erythrocytic Cycle ◽  
Rhoptry Protein

The rhoptry is an organelle of the malarial merozoite which has been suggested to play a role in parasite invasion of its host cell, the erythrocyte. A monoclonal antibody selected for reactivity with this organelle identifies a parasite synthesized protein of 110 kD. From biosynthetic labeling experiments it was demonstrated that the protein is synthesized midway through the erythrocytic cycle (the trophozoite stage) but immunofluorescence indicates the protein is not localized in the organelle until the final stage (segmenter stage) of intraerythrocytic development. Immunoelectron microscopy shows that the protein is localized in the matrix of the rhoptry organelle and on membranous whorls secreted from the merozoite. mAb recognition of the protein is dithiothreitol (DTT) labile, indicating that the conformation of the epitope is dependent on a disulfide linkage. During erythrocyte reinvasion by the extracellular merozoite, immunofluorescence shows the rhoptry protein discharging from the merozoite and spreading around the surface of the erythrocyte. The protein is located in the plasma membrane of the newly invaded erythrocyte. These studies suggest that the 110-kD rhoptry protein is inserted into the membrane of the host erythrocyte during merozoite invasion.

scholarly journals Absence of one component of spectrin adenosine triphosphatase in hereditary spherocytosis

Blood ◽  
1975 ◽  
Vol 46 (6) ◽  
pp. 945-954
Author(s):  
FH Kirkpatrick ◽  
GM Woods ◽  
PL La Celle
Keyword(s):  
Atpase Activity ◽  
Soluble Protein ◽  
Adenosine Triphosphatase ◽  
Hereditary Spherocytosis ◽  
Water Soluble ◽  
Water Soluble Protein ◽  
Normal Water ◽  
Calcium And Magnesium ◽  
Low Levels ◽  
Increased Activity

The stimulation by calcium and magnesium of ATPase activity of isolated ghosts, of water-soluble protein (spectrin), and of residual vesicles, derived from normal erythrocytes and from hereditary spherocytes (H.S.), has been measured. The ATPase activity found in normal water- soluble protein (WSP) at low levels of calcium (0.1–2.0 mM) is essentially absent in H.S. water-soluble protein, but the ATPase activity with magnesium and with high levels of calcium (60-100 mM) is the same in H.S. and normal WSP. Compared to normal, H.S. ghosts have increased Mg2+-stimulated activity. This increased activity is retained by the sedimentable vesicles (“residue”) after extraction of the ghosts with 0.025 mM EDTA. The Ca2+, Mg2+-ATPase associated with the calcium pump is not significantly different in H.S.

scholarly journals Identification of sulfenylation patterns in trophozoite stage Plasmodium falciparum using a non-dimedone based probe

2021 ◽  
Vol 242 ◽  
pp. 111362
Author(s):  
Susanne Schipper ◽  
Hanzhi Wu ◽  
Cristina M. Furdui ◽  
Leslie B. Poole ◽  
Claire M. Delahunty ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Trophozoite Stage

scholarly journals Malaria parasites both repress host CXCL10 and use it as a cue for growth acceleration

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yifat Ofir-Birin ◽  
Hila Ben Ami Pilo ◽  
Abel Cruz Camacho ◽  
Ariel Rudik ◽  
Anna Rivkin ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Life Cycle ◽  
Cerebral Malaria ◽  
Survival Strategy ◽  
Parasitic Disease ◽  
Malaria Parasites ◽  
Sensing System ◽  
Rich Domain ◽  
Cargo Delivery ◽  
Low Levels

AbstractPathogens are thought to use host molecular cues to control when to initiate life-cycle transitions, but these signals are mostly unknown, particularly for the parasitic disease malaria caused by Plasmodium falciparum. The chemokine CXCL10 is present at high levels in fatal cases of cerebral malaria patients, but is reduced in patients who survive and do not have complications. Here we show a Pf ‘decision-sensing-system’ controlled by CXCL10 concentration. High CXCL10 expression prompts P. falciparum to initiate a survival strategy via growth acceleration. Remarkably, P. falciparum inhibits CXCL10 synthesis in monocytes by disrupting the association of host ribosomes with CXCL10 transcripts. The underlying inhibition cascade involves RNA cargo delivery into monocytes that triggers RIG-I, which leads to HUR1 binding to an AU-rich domain of the CXCL10 3’UTR. These data indicate that when the parasite can no longer keep CXCL10 at low levels, it can exploit the chemokine as a cue to shift tactics and escape.

THE SOLUBLE PROTEINS OF THE MUSCLE TISSUE OF THE HADDOCK

1931 ◽  
Vol 6 (1) ◽  
pp. 1-11 ◽  
Author(s):  
J. F. LOGAN
Keyword(s):  
Sodium Chloride ◽  
Aqueous Solutions ◽  
Muscle Tissue ◽  
Soluble Protein ◽  
Potassium Phosphate ◽  
Extraction Methods ◽  
Water Soluble ◽  
Tabular Form ◽  
Water Soluble Protein ◽  
Isoelectric Points

As a contribution to the chemistry of muscle tissue, the solubility of the protein of haddock muscle in aqueous solutions of sodium chloride and neutral potassium phosphate, respectively, was determined. The results are expressed in tabular form and graphically in the form of solubility curves. A water-soluble protein and also a salt-soluble protein were isolated from dialyzed haddock muscle by extraction methods. These proteins were obtained in a comparatively pure condition by precipitation from solution in the region of their isoelectric points.

FRACTIONATION OF LIVETIN AND THE MOLECULAR WEIGHTS OF THE α- AND β-COMPONENTS

1957 ◽  
Vol 35 (4) ◽  
pp. 241-250 ◽  
Author(s):  
W. G. Martin ◽  
J. E. Vandegaer ◽  
W. H. Cook
Keyword(s):  
Light Scattering ◽  
Soluble Protein ◽  
Soluble Fraction ◽  
Egg Yolk ◽  
Water Soluble ◽  
Water Soluble Fraction ◽  
Molecular Weights ◽  
Water Soluble Protein ◽  
Hen Egg Yolk ◽  
Hen Egg

Livetin, the major water-soluble protein of hen egg yolk, was found to contain three major components having mobilities of −6.3, −3.8, and −2.1 cm.2 sec.−1 volt−1 at pH 8, µ 0.1, and these have been designated α-, β-, and γ-livetin respectively. The α- and β-livetins were separated and purified electrophoretically after removal of γ-livetin by precipitation from 37% saturated ammonium sulphate or 20% isopropanol. The α-, β-, and mixed livetins resembled pseudoglobulins in solubility but γ-livetin was unstable and this loss of solubility has, so far, prevented its characterization. Molecular weights determined by light scattering, osmotic pressure, and Archibald sedimentation procedure yielded respectively: 8.7, 7.8, and 6.7 × 104 for α-livetin, and 4.8, 5.0, and4.5 × 104 for β-livetin. Under suitable conditions of sedimentation and electrophoresis, egg yolk has been shown to contain three components having the same behavior as the three livetins of the water-soluble fraction.

Effect of Ginkgo Protein on Moisture Content and Hardness of Bread

2012 ◽  
Vol 531 ◽  
pp. 395-398
Author(s):  
Xiao Fei Sun ◽  
Yu Hui Qiao
Keyword(s):  
Moisture Content ◽  
Shelf Life ◽  
Total Protein ◽  
Soluble Protein ◽  
Water Soluble ◽  
Experimental Results ◽  
Water Soluble Protein

Ginkgo seeds were selected and used as experimental material to study protein compositions in ginkgo protein. Ginkgo protein was used as accessory to be added into flour to make bread. Effect of ginkgo protein on moisture content and hardness of bread were investigated. Experimental results showed that ginkgo protein contained water-soluble protein and salt-soluble protein which was 85.28 percents in total protein and contained small amounts of prolamin and alkali-soluble protein. The bread added with different ratios of ginkgo protein had higher moisture content and lower hardness. Therefore, adding appropriate amount of ginkgo protein could improve bread baking performances and bread shelf life.

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