High Molecular Weight Proteins ofTrypanosoma cruziReduce Cross-Reaction withLeishmaniaspp. in Serological Diagnosis Tests

Chagas disease is caused by the parasiteTrypanosoma cruzi. Because of its distribution throughout Latin America, sometimes it can overlap with other parasitic diseases, such as leishmaniasis, caused byLeishmaniaspp. This might represent a problem when performing serological diagnosis, because both parasites share antigens, resulting in cross-reactions. In the present work we evaluated Mexican sera samples: 83.8% of chagasic patients recognized at least one antigen of high molecular weight (>95 kDa) when evaluated by Western blot. Proteins of 130 kDa and 160 kDa are predominantly being recognized by asymptomatic chagasic patients. When the proteins were extracted using Triton X-100 detergent, a larger number of specificT. cruziproteins were obtained. This protein fraction can be used to increase specificity to 100% in Western blot assays without losing sensitivity of the test. High molecular weight proteins ofT. cruziinclude glycoproteins with a great amount ofαMan (α-mannose),αGlc (α-glucose), GlcNAc (N-acetylglucosamine), andαGal (α-galactose) content and these structures play an essential role in antigens recognition by antibodies present in patients’ sera.

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The polymerization of actin. III. Aggregates of nonfilamentous actin and its associated proteins: a storage form of actin.

The Journal of Cell Biology ◽

10.1083/jcb.69.1.73 ◽

1976 ◽

Vol 69 (1) ◽

pp. 73-89 ◽

Cited By ~ 75

Author(s):

L G Tilney

Keyword(s):

Molecular Weight ◽

Ionic Strength ◽

High Molecular Weight ◽

Careful Examination ◽

Filament Formation ◽

Heavy Meromyosin ◽

Associated Proteins ◽

High Molecular Weight Proteins ◽

Divalent Salts ◽

Triton X

When echinoderm sperm are treated with the detergent Triton X-100 at pH 6.4 in 10 mM phosphate buffer, the membranes are solubilized, but the actin which is located in the periacrosomal region remains as a phase-dense cup. These cups can be isolated free from the flagella and chromatin and can be solubilized by increasing the pH to 8.0 and by changing the ionic strength and type of buffer used. Since the actin does not exist in the "F" state in unreacted sperm, and since the actin remains as a unit that does not diffuse away, it must be present in the mature sperm in a bound or storage state. The actin is, in fact, associated with a pair of proteins whose mol wt are 250,000 and 230,000. When the isolated cups are digested with trypsin, these high molecular weight proteins are digested, thereby liberating the actin. The actin will polymerize if heavy meromyosin or subfragment 1 is added to a preparation of isolated cups. Evidence is presented that this pair of high molecular weight proteins is similar in molecular weight and properties to erythrocyte spectrin. Attempts at transforming the storage form of actin in the cup into filaments were only moderately successful. The best conditions for filament formation involve incubating the cup in ATP and divalent salts. Careful examination of these cups reveals that the actin polymerized preferentially on either end of oriented filaments that already exist in the cup, indicating that self-nucleation is inefficacious. I conclude that the actin can exist in the storage form by its association with spectrin-like molecules and that the actin in this state polymerizes preferentially onto existing filaments.

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INTERFERENCE BY SERUM PROTEINS WITH LH RADIOIMMUNOASSAY USING IMMUNOSORBENT

Acta Endocrinologica ◽

10.1530/acta.0.0720235 ◽

1973 ◽

Vol 72 (2) ◽

pp. 235-242 ◽

Cited By ~ 11

Author(s):

A. M. Reuter ◽

J. C. Hendrick ◽

J. Sulon ◽

P. Franchimont

Keyword(s):

Molecular Weight ◽

Human Serum ◽

High Molecular Weight ◽

Serum Proteins ◽

Void Volume ◽

High Molecular Weight Proteins ◽

Serum Fractionation ◽

Covalently Bound

ABSTRACT The percentage of LH* bound to antibodies that have been covalently bound to cellulose is diminished in the presence of LH-free human serum and sera from various species of animals. Serum fractionation studies on Sephadex G 200 show that the greatest interference comes from the proteins eluted in the void volume i. e. the high molecular weight proteins. Specifically, the gamma M globulins and the α2-macroglobulins appear to play an important role, as demonstrated by tests in which these proteins were neutralized by gamma M and α2-macroglobulin antisera.

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Faculty Opinions recommendation of Quantitative NMR studies of high molecular weight proteins: application to domain orientation and ligand binding in the 723 residue enzyme malate synthase G.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1013349.190158 ◽

2003 ◽

Author(s):

H Jane Dyson

Keyword(s):

Molecular Weight ◽

Ligand Binding ◽

High Molecular Weight ◽

Malate Synthase ◽

Nmr Studies ◽

Quantitative Nmr ◽

Domain Orientation ◽

Malate Synthase G ◽

High Molecular Weight Proteins

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Characterization of glycoconjugates of human gastrointestinal mucosa by lectins. II. Lectin binding to the isolated glycoproteins of normal and malignant gastric mucosa.

Journal of Histochemistry & Cytochemistry ◽

10.1177/32.7.6429236 ◽

1984 ◽

Vol 32 (7) ◽

pp. 690-696 ◽

Cited By ~ 15

Author(s):

J Fischer ◽

G Uhlenbruck ◽

P J Klein ◽

M Vierbuchen ◽

R Fischer

Keyword(s):

Molecular Weight ◽

Gastric Mucosa ◽

High Molecular Weight ◽

Lectin Binding ◽

Gel Filtration ◽

Molar Ratio ◽

Gastric Cancer Cells ◽

Tissue Sections ◽

Gradient Gel Electrophoresis ◽

Triton X

Using affinity chromatography on HPA-, PNA-, Con A, and WGA-agarose columns only a part (10-30%) of the high molecular weight mucous glycoproteins could be isolated from the Triton X-100 solubilized components of normal as well as carcinomatous gastric mucosa. The main part of the mucus was not bound by the lectins, which corresponds to our earlier lectin histochemical observations on paraffin-embedded tissue sections. The lectin-bound mucous glycoproteins had a relatively lower molecular weight, ranging from about 250-1,000 kilodaltons, as indicated by polyacrylamide gradient gel electrophoresis and by gel filtration on Biogel A 1.5 m column. In gas chromatographic analysis the molar ratio of aminohexoses to galactose was found to be much higher (3:1) in the lectin-bound mucous substances than in the whole high molecular weight mucus (1:1). This finding indicates that lectins have a higher affinity to the hexosamine rich components of mucus, which may be special forms of mucous glycoprotein molecules or the incompletely glycosylated core and backbone regions of the oligosaccharide chains of mucus. Extremely high hexosamine values (10:1) were found in the PNA isolated mucus of gastric adenocarcinoma. Since it is known that PNA binds to the terminal disaccharide, beta-galactose-(1-3)-N-acetylgalactosamine, which is localized at the reducing end of the oligosaccharide chains of mucus, it is highly probable that the elongation of the oligosaccharide side chains is disturbed in gastric cancer cells.

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