A nephelometric assay of concanavalin-A binding of serum acute phase proteins (con-A binding) has been used in cross-sectional and sequential studies of disease activity in rheumatoid arthritis (RA). Con-A binding correlated well with blood viscosity, C-reactive protein, and other individual acute phase reactants in patients with active RA. Twenty-four patients were treated for 6 months with D-...

Human lymphoblasts in long-term culture are specifically agglutinated by concentrations of concanavalin A that do not agglutinate normal human lymphocytes. The agglutination is inhibited by a-D-methyl mannoside. Lymphoblast lines kept in long-term culture bound 2 to 3 times more concanavalin A per cell than did normal lymphocytes. Normal lymphocytes and lymphoblasts bound approximately equivale...

T-lymphocyte subpopulations were studied in a group of patients with rhinoscleroma due to Klebsiella rhinoscleromatis. The data demonstrated that these patients had a significantly greater number of T-suppressor/cytotoxic lymphocytes than did clinically healthy individuals. This finding correlated with a diminished response to the T-cell mitogen concanavalin A. The evidence indicated that the T...

The spectral characteristics of dextran, labeled with fluorescein, depend upon pH. We have loaded the lysosomes of mouse peritoneal macrophages with this fluorescence probe and used it to measure the intralysosomal pH under various conditions. The pH of the medium has no effect on the intralysosomal pH. Weakly basic substances in the medium cause a concentration-dependent increase in the intral...

The carbohydrate binding sites of the jack bean lectin, concanavalin A, were studied spectrophotometrically. A number of ligands were examined for their ability to displace the chromogenic ligand p-nitrophenyl cr-n-mannopyranoside. It is shown that this technique provides a simple and convenient approach for obtaining association constants for a series of displacing ligands. The data can best b...

The ability of the jack bean lectin concanavalin A (ConA) to bind seven membered ring (septanose) monosaccharides has been investigated by isothermal titration calorimetry (ITC) and saturation transfer difference (STD) NMR spectroscopy.

Concanavlin A (ConA), a lectin found in jack-beans can bind to multiple sugars, as can cell receptors found on cheek epithelial cells and erythrocytes. By using horseradish peroxidase and hemagglutination, the effects of mannose and galactose on ConA binding were observed. Galactose had no effect on ConA but mannose bound with more affinity to ConA, competed negatively with the cell receptors, ...

Cells of the beige mouse contain abnormally large lysosomes and show enhanced capping of concanavalin A. It has been suggested that these phenomena may be secondary to a defect in microtubule polymerization. We have examined the cytoskeleton of beige mouse cells by indirect immunofluorescence and find the number and distribution of microtubules and actin cables to be indistinguishable from thos...

A viscometer suitable for rapid measurements in small volumes of highly viscous liquids is described. Using this device the viscometric affinity assay for glucose was studied under variable conditions in order to obtain basic information for the design of a viscometric glucose sensor. The viscosity of the dextran/Concanavalin A (ConA) solution is sensitive to glucose in a broad range of the she...

Genes mapping in the I region of the H-2 complex control a system of lymphocyte alloantigens (Ia) which are expressed on a subpopulation of T cells and on most B cells. Specific anti-Ia serum in the presence of rabbit complement removed the splenic T-cell subpopulation responsive to Con-A, but did not affect the response to phytohemagglutinin (PHA) or Leucoagglutinin. Antibodies specific for Ia...