The combined application of thin-section and critical-point-drying "fracture-label" is used to determine the pattern of distribution and partition of wheat-germ agglutinin and concanavalin A binding sites on the membrane faces of freeze-fractured exocrine and endocrine rat pancreatic cells. Whereas the exoplasmic face of plasma membrane is preferentially labeled by both lectins, the endoplasmic...

Untreated mouse peritoneal macrophages as well as macrophages treated with concanavalin A (ConA) were incubated in the presence of untreated or ConA-treated epimastigotes and trypomastigotes of Trypanosoma cruzi. Treatment of epimastigotes or trypomastigotes with ConA increased or decreased their uptake by macrophages, respectively. Treatment of their macrophages with ConA reduced by 70% and in...

Lipopolysaccharide induces a synergistic uptake of tritiated thymidine in peripheral blood lymphocytes (PBL) when cultured with phytohemagglutinin or concanavalin A as compared to PBL incubated only with phytohemagglutinin or concanavalin A. In this study we investigated which subpopulations(s) of PBL is involved in this synergistic increase in deoxyribonucleic acid synthesis. Separation of PBL...

Transformed fibroblasts had a low content of ATP when grown at a high cell density and a high content of ATP when grown at a low cell density. Concanavalin A agglutinated transformed cells with a low, but not those with a high, ATP content. Transformed cells with a high ATP content gained agglutinability after ATP depletion by inhibitors of the energy-generating systems, and those with a low AT...

A new crystal form of concanavalin A, a well studied lectin from the jack bean (Canavalia ensiformis) is reported. These crystals, with the symmetry of orthorhombic space group C222(1), grow as large roughly equi-dimensional blocks. Unit-cell parameters at 120 K are a = 118.67 (12), b = 101.36 (13), c = 111.94 (9) A. On density considerations for two molecules per asymmetric unit, the water con...

Interferon treatment impairs the ability of cells to redistribute cell surface receptors for concanavalin A (Con A). The effect of interferon becomes evident within 3-6 h and is maximal within 36-48 h. Highly purified human fibroblast interferon (> 2 x 10(8) U/mg of protein sp act; concentration; 640 U/ml) caused approximately 85% inhibition of capping of fluorescein-conjugated Con A in interfe...

Binding sites analogous to those of sp(3) carbon are presented by concanavalin A. This lectin has now been cross-linked with a bismannopyranoside which contains the C(2) spacer required to form the computer-modeled diamondlike three-dimensional protein lattice shown in the picture.

Density-inhibited 3T3 mouse fibroblasts were treated for 10 min with nine concentrations of Pronase ranging from 0.25 to 40 mug/ml. Concanavalin A-specific agglutinability increased from control values of about 25% to plateau values of about 80%. None of these Pronase concentrations brought about an increase in cell number within 84 hr. Pronase-treated cells remained responsive to growth stimul...

Inhibition studies on the concanavalin A-dextran interaction have been extended using as inhibitors the members of the maltose-, isomaltose-, and methyl cy-isomaltoside series, amino and N-acetyl amino sugars, and a number of oligosaccharides containing more than one linkage type. The interaction of the plant protein at the terminal chain ends of the a-linked glucans and mannans has been essent...