An increase in the free cytoplasmic Ca2+ concentration in thymocytes can be detected by the fluorescent indicator quin 2 within a few seconds of the addition of concanavalin A and the response is quantified from the increased proportion of quin 2 in the cells chelated by Ca2+ ('% Ca-quin 2'). The % Ca-quin 2 in untreated cells is 53 +/- 6%, increases to 64 +/- 7% immediately after the addition ...

The current use of concanavalin A, the phytohemagglutinin of the jack bean ~ , as a probe for investigating membranous glycoproteins and glycolipids requires a detailed knowledge of the protein's specificity. Extensive hapten inhibition studies employing monoand oligosaccharides and their simple derivatives demonstrated that the concanavalin A combining sites are complimentary to ct-D-mannopyra...

The inhibition of protein synthesis in Chinese hamster V79 cells by diphtheria toxin is antagonized by the lectins concanavalin A, succinylated concanavalin A, and wheat germ agglutinin but not by Proteus vulgaris phytohemagglutinin or abrus agglutinin. The effects of concanavalin A and wheat germ agglutinin are reversed by methyl alpha-mannoside and N-acetylglucosamine, respectively. The inhib...

1. Gastric juice, saliva and ovarian-cyst fluid were fractionated into glycoprotein components by centrifuging to equilibrium in a caesium chloride density gradient. 2. The glycoprotein fractions from the gastric juice of two group O non-secretors, two group O secretors and three group A secretors all formed insoluble complexes with concanavalin A. 3. Fractions showing maximum interaction with ...

We investigate the sensitivity of femtosecond Fourier transform two-dimensional infrared spectroscopy to protein secondary structure with a study of antiparallel beta-sheets. The results show that 2D IR spectroscopy is more sensitive to structural differences between proteins than traditional infrared spectroscopy, providing an observable that allows comparison to quantitative models of protein...

Trypsinized BHK cells become attached to glass that has been derivatized with a variety of lectins with well-defined specificity for cell-surface carbohydrates. Provided a threshold concentration of glass-immobilized protein is present the cells undergo a transformation to a well-spread morphology. The matrix density of lectins (ricin and concanavalin A) required to trigger this morphological t...