ABSTRACT
Study was carried out to understand and compare architecture of the proteins of erythrocyte cell surface of some mammals viz., Homo sapiens (human), Sus scorfa domestica (pig) and Bos taurus domestica (cow). In this study, we investigated the action of proteinases viz., trypsin and chymotrypsin and neuraminidase on the erythrocyte surface proteins and erythrocyte agglutination tendency with a lectin (concanavalin A). The electrophoretic pattern of membrane proteins and glycophorins (analyzed by SDS-PAGE and visualized by Coomassie brilliant blue and periodic acid-schiff stains, respectively) and concanavalin A (Con A) agglutinability revealed that: (i) There were variations in the number and molecular weights of glycophorins in human, pig and cow, (ii) trypsin action on pig and cow erythrocyte membrane proteins was similar, unlike human, (iii) glycophorins degradation by trypsin and chymotrypsin was not similar in pig, as compared to that of human and cow, (iv) erythrocytes agglutination with Con A was significantly different due to differences in membrane composition and alterations in the surface proteins after enzyme treatment, (v) a direct correlation was found between degradation of glycophorins and Con A agglutinability, and (vi) removal of erythrocyte surface sialic acids by neuraminidase specifically indicated an increase in Con A agglutinability of pig and cow erythrocytes, similar to human.
Subject(s)
Animals , Cattle , Cells, Cultured , Concanavalin A/metabolism , Erythrocyte Membrane/drug effects , Erythrocyte Membrane/metabolism , Hemagglutination/drug effects , Hemagglutination/physiology , Humans , Membrane Proteins/metabolism , Peptide Hydrolases/pharmacology , SwineABSTRACT
The purification, structural and functional characterization of two different lectins (named Svl-1 and Svl-2) has been reported from the marine sponge Spheciospongia vesparia. Purification procedure includes ammonium sulfate precipitation, combined with chromatography including Octyl-Sepharose-(NH4)SO4 hydrophobic column and DEAE-Toyopearl anion-exchange column using a high performance liquid chromatography. The similarities in function, specificity for saccharides, molecular weight, amino acid content and the N-terminal sequence of two lectins suggest that these proteins are isolectins. Amino acid composition and fluorescence analyses reveal that they contain an intrachain disulfide bridge, which might contribute to their high thermal stability. Furthermore, the purified lectins exhibit antibacterial activity against the gram-negative bacteria Pseudomonas aeruginosa and E. coli, indicating that they may be involved in a recognition strategy and may play a role in the defense response function of the sponge. This is the first report on the isolation of lectins from the S. vesparia. The purified lectins represent a potential possible candidate for future application in the recognition or treatment of cancer cells.
Subject(s)
Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/isolation & purification , Anti-Bacterial Agents/pharmacology , Aquatic Organisms/chemistry , Bacteria/drug effects , Hemagglutination/drug effects , Humans , Lectins/chemistry , Lectins/isolation & purification , Lectins/pharmacology , Porifera/chemistry , Sequence Analysis , Sequence HomologyABSTRACT
Forty-five strains of Shigella were screened for haemagglutinin production and broad-spectrum haemagglutination reaction. Mannose-sensitive haemagglutinin (MSHA) was found in 22 strains [Shigella flexneri (7), S. dysenteriae (7), S. sonnei (3), and S. boydii (5)]. Eighteen strains harboured mannose-resistant haemagglutinin (MRHA), and 8 strains were observed to be non-haemagglutinating to guinea pig erythrocyte. With the exception of human erythrocytes (O, A, B, and AB), the observed MSHA and MRHA also agglutinated the erythrocytes of rabbit, sheep, rat, chicken, and horse, suggesting a broad-spectrum haemagglutinating property. Haemagglutinins of S. flexneri and S. dysenteriae elicited a relatively stronger haemagglutinating activity with agglutinability to chicken and rabbit erythrocytes enhanced by trypsinization. Haemagglutination reaction with guinea pig erythrocyte was generally inhibited by sialic acid, while simple sugars, such as D-glucose, D-galactose, N-acetylgalactosamine, N-acetylglucosamine, and D-rhamnose, elicited no inhibitory effect. The results of the study revealed broad-spectrum haemagglutinin expression by circulating Shigella strains in Nigeria.
Subject(s)
Animals , Bacterial Adhesion , Chickens , Erythrocytes/metabolism , Guinea Pigs , Hemagglutination/drug effects , Hemagglutinins/metabolism , Horses , Humans , Nigeria , Rabbits , Rats , Sheep , Shigella/physiology , Trypsin/pharmacologyABSTRACT
The antimicrobial, hemagglutinating and toxic activities of the purple fluid of the sea hare Aplysia dactylomela are described. Intact or dialyzed purple fluid inhibited the growth of species of Gram-positive and Gram-negative bacteria and the action was not bactericidal but bacteriostatic. The active factor or factors were heat labile and sensitive to extreme pH values. The fluid preferentially agglutinated rabbit erythrocytes and, to a lesser extent, human blood cells, and this activity was inhibited by the glycoprotein fetuin, a fact suggesting the presence of a lectin. The fluid was also toxic to brine shrimp nauplii (LD 50 141.25 µg protein/ml) and to mice injected intraperitoneally (LD 50 201.8 ñ 8.6 mg protein/kg), in a dose-dependent fashion. These toxic activities were abolished when the fluid was heated. Taken together, the data suggest that the activities of the purple fluid are due primarily to substance(s) of a protein nature which may be involved in the chemical defense mechanism of this sea hare
Subject(s)
Animals , Rabbits , Mice , Aplysia , Bacteria/drug effects , Body Fluids , Hemagglutination/drug effects , Bacteria/growth & development , Electrophoresis, Polyacrylamide Gel , Growth Inhibitors , Microbial Sensitivity TestsABSTRACT
Se estudiaron 45 pacientes, a quienes se les aisló Pseudomonas aeroginosa en diversas muestras clínicas, sin evaluarse en la mayoría de ellos su asociación con contaminación, colonización o infección clínicamente significante. A todos ellos se les determinó los títulos de anticuerpos vs lipopolisacáridos de pseudomonas aeroginosa, el cual fue obtenido a partir de la aislada a cada uno de ellos, observándose que el 51.11 por ciento mostraron títulos por debajo de 1:80 en la primera muestra, de éstos 19 (82.7 por ciento ) elevaron sus títulos en la segunda muestra, mientras que los 4 restantes (17.3 por ciento ), mantuvieron estables sus títulos en dicha muestra. En el 48.89 por ciento encontramos títulos por encima de 1:80 en la primera muestra. De estos 6 (27.2 por ciento ) bajaron sus títulos en la segunda muestra, 14 (27.2 por ciento ) los elevaron y 2 (9.10 por ciento ) los mantuvieron estables. Sólo encontramos 4 pacientes (8.89 por ciento ) a quienes no fue posible detectar anticuerpos en ninguna de las 2 muestras estudiadas y en todos ellos la cepa fue aislada de orina
Subject(s)
Humans , Antibodies, Bacterial , Epidemiology , Hemagglutination/drug effects , Lipopolysaccharides , Pseudomonas aeruginosaABSTRACT
Effect of alkaloidal fraction of aqueous extract of T. malabarica (Tm) was studied on humoral antibody responses in rats and guineapigs. The anti-SRBC haemagglutination titre was found to be enhanced in rats pretreated with Tm (2.5 mg/kg). Passive cutaneous anaphylaxis (PCA) in rats was also increased in Tm treated group. In vitro experiments with sensitized rat peritoneal mast cells showed a significant decrease in antigen-induced various spasmogens on isolated guineapig ileum.