The alpha-galactosyl specific lectin from Artocarpus integrifolia distinguishes between two lymphoma lines with different metastatic potential.

A lectin purified from the seeds of the Vietnamese Artocarpus integrifolia distinguishes between the mouse T-cell lymphoma cell lines Eb and ESb, with low and high metastatic potential, respectively. It agglutinates Eb cells as well as human erythrocytes, but not ESb cells or the human colon carcinomas cells HT29. The haemagglutinin is specific for alpha-galactosyl residues and has a molecular mass of 62 kDa.

A lectin from the Asian horseshoe crab Tachypleus tridentatus: purification, specificity and interaction with tumour cells.

A lectin from the haemolymph of the Asian horseshoe crab Tachypleus tridentatus was purified to homogeneity by affinity chromatography on Sepharose 4B-bound N-acetylneuraminic acid. The specificity of this lectin was studied by haemagglutination inhibition with sialic acid analogues, N-acetylhexosamines and glycoproteins. For the interaction with the agglutinin the N-acetyl group and the glyceryl side chain of N-acetylneuraminic acid are important, while presence of an aglycon, specially an alpha-glycosidically linked lactose increases affinity to the lectin. The strongest glycoprotein inhibitors were ovine as well as bovine submaxillary mucin and Collocalia mucin, all being O-chain glycoproteins but carrying completely different carbohydrate chains. The majority of N-chain proteins were inactive. As the lectin agglutinates human erythrocytes, but not the murine lymphoma lines Eb and ESb or the human colon carcinoma HT 29, these cancer cells apparently lack the 'Tachypleus tridentatus agglutinin-receptor' which is present on red cells and O-chain glycoproteins.

A blood group A specific lectin from the seeds of Crotalaria striata.

A lectin, monospecific for human blood group A red blood cells was extracted from seeds of Crotalaria striata and purified by molecular sieving on Sephadex G-100 and ion-exchange on DEAE-cellulose. A molecular mass of 30 kDa was determined by SDS-polyacrylamide gel electrophoresis under non-reducing and reducing conditions. Molecular sieving on a Superose 12 column indicated a molecular mass of 110 kDa, suggesting the tetrameric nature of the native protein. Amino-acid composition showed the presence of aminated carbohydrate residues on the lectin. N-terminal amino-acid sequencing showed a striking similarity with the N-terminal sequence of the lectin from Crotalaria juncea, which is blood-group non-specific. The potency order of agglutination inhibition with galactose containing monosaccharides was N-acetyl-D-galactosamine greater than D-galactose greater than D-galactosamine as found for blood-group-A-specific lectins from other species.

Purification and properties of pig kidney glutamate dehydrogenase.

Glutamate dehydrogenase from pig kidney has been purified to homogeneity by means of affinity chromatography on matrix bound Cibacron Blue F3G-A and gel chromatography on Sepharose 6B. The enzyme exhibits allosteric properties with the substrates alpha-ketoglutarate, ammonium, and NADH, respectively. GTP is a strong inhibitor which strengthened the cooperative interactions between the ammonium binding sites. ADP as an activator relieves the inhibition by GTP. Like glutamate dehydrogenase from bovine liver, glutamate dehydrogenase from pig kidney shows the ability of self-association, too. The sedimentation coefficient increases from 13.5 S at 0.07 mg protein/ml to 19.4 S at 1.32 mg protein/ml. In the sodium dodecylsulphate gel electrophoresis the enzyme migrates as a single band with a molecular-weight at 51000.

Pig kidney phosphofructokinase. Purification to homogeneity and qualitative basic characterization.

Phosphofructokinase has been purified from pig kidney by extraction with phosphate buffer at pH 8, followed by alcohol treatment, affinity chromatography on matrix-bound Cibacron blue F3G-A, and gel chromatography on Sepharose 6B. Using sodium dodecyl sulphate electrophoresis the enzyme was found to be homogeneous and to have a specific activity of about 80 units/mg protein. Like other phosphofructokinases, at pH 7.0 the enzyme exhibits a sigmoidal dependence in its activity on the fructose 6-phosphate concentration and is strongly inhibited by ATP. The degree of citrate inhibition is influenced by the concentration of the two substrates. ATP strengthens and fructose 6-phosphate relieves the inhibition by citrate. AMP and cAMP are able to overcome the ATP inhibition. The ADP activation curve is biphasic. The molecular weight of the subunit of pig kidney phosphofructokinase was determined to be 88 000 by means of sodium dodecyl sulphate electrophoresis.