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H Lis

Publications and source records attributed to H Lis.

At least 55 records · Page 3Linked to original sources
PubMed1978

Mn2+-electron spin resonance spectra of several lectins.

Mn2+-ESR spectra of soybean, wax bean and lima bean agglutinin at Q- and X-band frequencies show nearly axially symmetric zero field splitting (ZFS); the dominant anisotropic term of the spin hamiltonian is the quadratic ZFS interaction. There is a relatively large distribution of ZFS parameters. No effects of specific inhibitor (N-acetylgalactosamine) on the soybean agglutinin spectrum were observed. The stoichiometric complex obtained on addition of Mn2+ to a Mn2+-free sample of this protein has a spectrum similar to that of the native protein. The small changes in the spectrum are interpreted in terms of a wider distribution of the ZFS parameters at the Mn binding site. Addition of Ca2+ to Mn2+-soybean agglutinin sharpens the lines, possibly because Ca2+ increases the rigidity of the complex.

Binding Sites↗
PubMed1976

Saccharides on teratocarcinoma cell plasma membranes. Their investigation with radioactively labelled lectins.

We have studied the interaction of five lectins differing in their sugar specificity, with the surface of clonal cell lines derived from transplantable murine teratocarcinoma. The results show that the differentiation from primitive embryonal carcinoma cells into parietal yolk sac cells is accompanied by changes in cell surface saccharides. These changes consist of a marked decrease in the total number of binding sites for the L-fucose-specific lectin of Lotus tetragonolobus and a large increase in the total number of binding sites for wax bean agglutinin. It is suggested that these differences can be used as markers in the study of this early embryonic differentiation. No agglutination of primitive embryonal carcinoma cells or of parietal yolk sac cells by low concentrations (10mug/ml) of concanavalin A, soybean agglutinin or the fucose binding proteins was observed.

Binding Sites↗
PubMed1976

The requirement for tetravalency of soybean agglutinin for induction of mitogenic stimulation of lymphocytes.

The mitogenic activity of soybean agglutinin was found to depend on the presence of lectin aggregates formed in lectin preparations stored in the lyophilized state. Such soybean agglutinin preparations gave maximal stimulation of untreated pig lymph node cells and neuraminidase-treated mouse spleen cells at relatively high concentrations, ranging from 100 to 2000 mug/ml. After separation into unaggregated (divalent) and polymeric (tetra-and multivalent) fractions, it was found that the unaggregated lectin did not stimulate the cells, while the tetravalent and multivalent fractions were active and gave maximal stimulation at a concentration of 10 mug/ml. These results suggest that soybean agglutinin must have at least four sugar binding sites in order to be able to stimulate lymphocytes.

Acetylgalactosamine↗