Site-Directed Mutagenesis Studies on the Lima Bean Lectin

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65875/1/j.1432-1033.1995.0958g.x.pd

INTERACTION OF CONCANAVALIN A WITH MODEL SUBSTRATES *

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72701/1/j.1749-6632.1974.tb53040.x.pd

Comparison of the binding properties of the mushroom Marasmius oreades lectin and Griffonia simplicifolia I-B 4 isolectin to αgalactosyl carbohydrate antigens in the surface phase

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73881/1/j.1399-3089.2004.00108.x.pd

An Immunochemical Study of the Combining Sites of the Second Lectin Isolated from \u3ci\u3eBandeiraea simplicifolia\u3c/i\u3e (BS II)

Two lectins with different binding specificities have been isolated from extracts of seeds of Bandeiraea simplicifolia. The first, Bandeiraea lectin I [11] was specific for terminal non-reducing αDGalactosyl residues. It reacted with B substances from human ovarian cysts and with several galactomannans to form precipitin lines in agar gels. Polysaccharides with terminal αDGalactosyl residues, such as larch galactan, did not react. The lectin agglutinated B erythrocytes strongly but also reacted to a lower titre with A1 and very weakly with A2 erythrocytes [15, 28] indicating that terminal non-reducing αDGalNAc [24] can be accommodated in the-site to some extent. Recently, it was shown that B. simplicifolia lectin I (BS I) consists of five isolectins each of which is a tetrameric glycoprotein composed of A and B subunits; the A subunits are specific for αDGalNAc, the B subunits for αDGal [30]. The second lectin, Bandeiraea lectin II (BS II), isolated by affinity chromatography on chitin [13], is a glycoprotein (molecular weight 113,000) of four subunits of molecular weight 30,000. It does not agglutinate A, B or O erythrocytes. Quantitative precipitin assays showed it to react better with BSA conjugated to p-azophenyl αDGalNAc than with the β compound. In inhibition studies, the unusual observation was made that N,N’-diacetylchitobiose (DGlcNAcβ1 → 4DGlcNAc) and pNO2 phenyl αDGalNAc were highly active; methyl αDGalNAc was only one half as active but was eight times more active than methyl βDGlcNAc

Characterization of gangliosides from Ehrlich ascites tumour cells and their variants

Differences in the nature of the gangliosides present in two types of Ehrlich ascites tumour (EAT) cells, the adherent and non-adherent EAT cells, were studied. Gangliosides were isolated by DEAE Sephadex column chromatography and analysed by high-performance thin-layer chromatography (HPTLC). The non-adherent EAT (na-EAT) cells which grow in the peritoneal cavity of mice were selected for growth on basement membrane and tissue culture plastic to give the adherent EAT (a-EAT) cells. na-EAT cells contained 1.57 nmol lipid-bound sialic acid per mg protein and at least 12 different gangliosides, including major gangliosides such as GM3, GM2, GM1, GD3, GD1a and GT1b. On the other hand, the ganglioside pattern of a-EAT cells differed significantly from that of na-EAT cells, both quantitatively and qualitatively. The content of lipid-bound sialic acid in a-EAT cells was only 0.24 nmol per mg of protein. The gangliosides in a-EAT cells were characterized as GD1a and trisialogangliosides and, significantly, a-EAT cells did not contain monosialogangliosides. Neutral glycolipids were isolated from both cell lines and their patterns were compared. In contrast to the gangliosides pattern, their neutral glycolipid patterns were similar. Glucosylceramide and lactosylceramide were the major components in both types of cells. In addition to na- and a-EAT cells, a-EAT cells were passaged in mice by intraperitoneal injection, giving rise to a third variant (c/m EAT cells). We analysed the gangliosides in c/m EAT cells to determine whether there was a change in the ganglioside pattern found in na-EAT cells. After repeated passage of c/m EAT cells in mice, the pattern of gangliosides shifted to that of na-EAT cells. Alterations of ganglioside composition may be associated with the growth environment of the murine peritoneal cavity; alternatively, a selection process may have occurred.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45681/1/10719_2004_Article_BF00731486.pd

S1.23 Investigation of the sialyltransferases present in two populations of ehrlich ascites tumor cells

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45635/1/10719_2005_Article_BF01209824.pd

Reexamination of the carbohydrate binding stoichiometry of lima bean lectin

The carbohydrate binding stoichiometry of lima bean lectin component III was reexamined using equilibrium dialysis and quantitative affinity chromatography following limited chemical modification. Equilibrium dialysis employing methyl[2-14C]benzamido-2-deoxy-[alpha]--galactopyranoside as ligand demonstrated that the lectin tetramer bound 4 mol of sugar with Kassoc = 1.44 +/- 0.13 x 103 m-1 (T = 5 [deg]C, pH 7.0, ionic strength 0.1). The previous report of two sites/tetramer [Bessler, W. and Goldstein, I. J. (1974) Arch. Biochem. Biophys. 165, 444] appears to be the result of partial inactivation of the lectin due to oxidation of essential thiol groups. Following limited chemical modification of the thiol groups by methyl methanethiosulfonate, multiple intermediate forms with reduced affinity for Synsorb A were obtained. The number and hemagglutinating activities of these intermediates provided further support for the presence of four carbohydrate binding sites on lima bean lectin component III.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24856/1/0000283.pd

Resolution of nucleotide sugars and oligosaccharides by lectin affinity chromatography

Bandeiraea simplicifolia I (BS I) isolectins, immobilized on Sepharose beads, specifically retarded low molecular weight ligands containing terminal [alpha]--galactopyranosyl and 2-acetamido-2-deoxy-[alpha]--galactopyranosyl residues. A BS I lectin-Sepharose column has been used to perform very efficient separations of structurally homologous sugar nucleotides and oligosaccharides. For example, UDP-glucose and UDP-galactose (and the corresponding 2-acetamido-2-deoxy derivatives) were separated by as much as three column volumes by a BS I lectin-Sepharose column. This column has also been used to resolve the alditols of lactose ([beta]--Galp-(1 --> 4)--Glc) and melibiose ([alpha]--Galp-(1 --> 6)--Glc), to analyze the radiochemical purity of UDP-galactose and UDP-N-acetyl--galactosamine preparations, and to analyze the relative proportions of UDP-N-acetyl--glucosamine and UDP-N-acetyl--galactosamine in the UDP-N-acetyl--hexosamine pool isolated from cultured cells.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23323/1/0000262.pd

Stimulation of the gerbil's gustatory receptors by monosaccharides

The gustatory responses of the Mongolian gerbil were tested with a large number of monosaccharides. Electrophysiological methods were used to record from the chorda tympani nerve. Methyl glycosides which have structural features in common with sucrose are the most effective monosaccharides for eliciting a neural response. Among the monosaccharides tested, efficacy appears to be highest in -pyranosides having equatorial substituents at the C-2 and C-4 positions and axial substituents at the C-1 position. A C-5 hydroxymethyl group is not required. Similarities in the structural requirements for taste response in the fly and gerbil are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/21722/1/0000114.pd

Interaction of concanavalin A, a phytohemagglutinin, with model substrates

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33447/1/0000850.pd