Seiichi Ohkuma

Purification and characterization of anti-N lectin from Vicia unijuga leaves.

1. An anti-N lectin was extracted from Vicia unijuga leaves with phosphate-buffered saline (PBS). Purification of the lectin was achieved, after pretreatment of the PBS extract by ammonium sulfate fractionation and absorption with human M erythrocytes, by using a combination of conventional chromatographic techniques with asialoglycophorin AN-Sepharose CL-4B affinity chromatography. Purification steps were followed by increase of specific activity. 2. Homogeneity of the purified lectin was demonstrated by HPLC and SDS-PAGE. The purified lectin was a glycoprotein with 11.4% carbohydrate and relatively high percentages of serine, threonine and aspartic acid residues and had a Mw of 120,000 Da. 3. This lectin agglutinated human N and MN erythrocytes, but did not agglutinate M erythrocytes. Hemagglutination of the lectin was inhibited by glycophorin AN and N-active sialoglycopeptide released from human N erythrocytes by treatment with Pronase or trypsin. However, it was not inhibited by any of mono- and di-saccharides, ABH-active glycoproteins, glycophorin AM and M-active sialoglycopeptide liberated from human M erythrocytes by treatment with Pronase or trypsin.

Presence of a Vicia unijuga lectin-binding (Vgu) glycoprotein with Thomsen-Friedenreich (T) activity and Vgu glycoproteins in human primary hepatocellular carcinoma.

1. Twenty perchloric acid-soluble glycoprotein fractions (PASFs) were separated from carcinomatous and non-carcinomatous regions of the livers of 5 patients with primary hepatocellular carcinoma (HCC) and 5 patients with a complication of HCC and hepatocirrhosis (HC). 2. In autoradiography using 125I-labelled Vicia unijuga lectin (VUA) and 125I-labelled Arachis hypogaea anti-T lectin as probes, 10 PASFs from carcinomatous regions of the livers of 10 patients gave 1 Vgu glycoprotein with T activity and/or 1-4 Vgu glycoproteins, respectively, and among 10 PASFs from non-carcinomatous regions of the livers of 10 patients, 7 PASFs gave no glycoproteins, respectively. 3. These results show that a Vgu glycoprotein with T activity and Vgu glycoproteins occur in HCC and in a complication of HCC and HC as oncofetal antigens.

Presence of influenza virus-reactive glycophorins other than glycophorin a in human erythrocyte membranes

The reactivities against seven hemagglutinins including influenza A and B viruses of six sialoglycoprotein (glycophorin) fractions, M-Frs.1-3 and N-Frs.1-3, separated from human OMs and ONs erythrocyte membranes by a combination of the LIS-phenol method and gel filtration were studied. The serological results show that M-Fr.1 and N-Fr.1 were glycophorins AM and AN, respectively, the reactivities against influenza A and B viruses of both M-Fr.2 and N-Fr.2 which contained glycophorins B and C were remarkably higher than that of glycophorin A and the reactivities against influenza viruses of both M-Fr.3 and N-Fr.3 which contained glycophorins B and D were considerably lower than that of glycophorin A.

Isolation and characterization of a novel sialic acid-specific lectin from hemolymph of Limulus polyphemus

Abstract 1. 1. A novel sialic acid-specific lectin was isolated from hemolymph of Limulus polyphemus by a combination of affinity chromatography with glycophorin HA as an immobilized ligand and gel filtration with Sephacryl S-300. 2. 2. The lectin with molecular weight of 436 kDa was a simple protein and comprised 15 subunits with molecular weight of 30 kDa. 3. 3. The agglutination of equine erythrocytes with the lectin was inhibited by N-acetylneuraminic acid, N-glycolylneuraminic acid, glycophorins AM, AN and HA and some sialoglycoproteins, but not inhibited by any of neutral saccharides, hexosamines, N-acetylhexosamines, glucuronic acid, ABH-active glycoproteins and several asialoglycoproteins.