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Biomedical subjects

F Sakakibara

Publications and source records attributed to F Sakakibara.

At least 55 records · Page 3Linked to original sources
PubMed1987

Amino acid sequence of sialic acid binding lectin from frog (Rana catesbeiana) eggs.

The complete amino acid sequence of sialic acid binding lectin from frog (Rana catesbeiana) egg is presented. The 111-residue sequence was determined by the analysis of peptides generated by digestion of the S-carboxymethylated protein with Achromobacter protease I, chymotrypsin, or cyanogen bromide. The sequence is unique and not homologous to any known protein sequence. The protein may represent a new type of lectin.

Amino Acid Sequence↗
PubMed1987

Induction of release of cytotoxin from murine bone marrow cells by an animal lectin.

An animal lectin purified from loach (Misgurnus anguillicaudatus) eggs induced release of cytotoxin from fresh bone marrow cells from mice, although the other lectins tested, wheat germ agglutinin, concanavalin A, and phytohemagglutinin did not. The cytotoxin released from bone marrow cells was a heat-labile protein with a molecular weight of 70,000. The main cells responsible for release of Mr 70,000 cytotoxin seemed to be of macrophage lineage, since they adhered to plastic and were sensitive to certain antibodies for markers of macrophages. However, they did not express asialo GM1 antigen which is expressed by activated macrophages. Removal of cells that phagocytized iron did not diminish but rather enhanced the release of cytotoxin. Therefore, active bone marrow cells appeared to be immature, not mature macrophages. These data suggest that immature bone marrow cells that are not specifically activated have a cytolytic potency against tumor cells and that internal animal lectins may induce release of the cytotoxin from these cells.

Animals↗
PubMed1986

Induction of a cytotoxin from murine macrophages by an animal lectin.

Vertebrate lectin purified from loach eggs stimulated release of cytotoxin from BCG-or glucan (TAK)-elicited peritoneal macrophages and a murine macrophage cell line (J774.1), but not from resident peritoneal cells. The cytotoxin released from J774.1 cells on stimulation with loach egg lectin was a heat-labile protein with a molecular weight of about 55K.

Animals↗
PubMed1985

Blood group B-specific lectin of Plecoglossus altivelis (Ayu fish) eggs.

A lectin that agglutinates human blood group B erythrocytes but not blood group A and O erythrocytes was isolated from eggs of Ayu sweet fish (Plecoglossus altivelis). The lectin also agglutinates Ehrlich ascites carcinoma cells but not rat ascites hepatoma AH109 or rat sarcoma 150 cells tested. The lectin agglutination was most effectively inhibited by monosaccharides with the first type of configuration, i.e., L-rhamnose, L-mannose and L-lyxose at a concentration of 0.03 mM. The lectin agglutination was moderately inhibited by monosaccharides with the second type of configuration, i.e., D-galactose, D-fucose and D-galacturonic acid at a concentration of 0.4 mM. However, the agglutination was not inhibited by various other monosaccharides and oligosaccharides that have other types of configuration. The basis for an apparent B-specific hemagglutination may be due to the steric similarity of the C2 and C4 of the galactosyl series, the B-specific determinant, and the L-rhamnosyl-Sepharose column and was characterized as a homogeneous low molecular weight protein (Mr 14000) with an abundance of hydrophobic amino acids and dicarboxylic amino acid.

ABO Blood-Group System↗
PubMed1984

Macrophage-mediated tumor lysis induced by loach egg lectin.

Vertebrate lectin purified from loach egg was tested for induction of tumor lysis mediated by macrophages. Loach egg lectin lysed tumor cells but not normal spleen cells in cooperation with BCG- or glucan (TAK)-elicited peritoneal macrophages of mice. Corynebacterium parvum-, OK432-, glycogen-, lipopolysaccharide-elicited or resident macrophages were not effective. Neither loach egg lectin nor BCG nor glucan macrophages alone had a cytolytic action on tumor cells. Thus, the vertebrate lectin from loach egg is a mediator in macrophage-mediated tumor lysis, inducing binding of macrophages to target cells. This lectin-dependent macrophage-mediated cytolysis (LDMC) was inhibited by galactose, N-acetylgalactosamine, fucose, or rhamnose. These results suggest that tumor cells can be recognized via glycoconjugates on cell membrane in addition to tumor-associated antigen and that some animal lectins participate in macrophage-mediated tumor lysis.

Animals↗
PubMed1979

Egg lectin of Rana japonica and its receptor glycoprotein of Ehrlich tumor cells.

Egg lectin of Rana japonica, which specifically agglutinates transformed cells but does not agglutinate nontransformed cells and erythrocytes, has been isolated by gel filtration and successive ion-exchange chromatographies on diethylaminoethyl cellulose and carboxymethylcellulose columns and has been characterized as a homogeneous carbohydrate-free protein with a relative molecular weight of 13,500. The lectin, at a concentration of 1 microgram/0.1 ml, causes obvious cytoagglutination of various transformed and tumor cell. The receptor of the Erlich ascites tumor cells which inhibits the lectin-induced agglutination of the Ehrlich ascites tumor cells has been isolated and characterized. The receptor was solubilized from Ehrlich ascites carcinoma cells by treating a tumor cell suspension with insolubilized trypsin, and the solubilized receptor was isolated by gel filtration through Sephadex G-100, followed by ion-exchange chromatography on diethylaminoethyl cellulose. The receptor was identified as a homogeneous glycoprotein having about 25% carbohydrate. The receptor, at a concentration of 4 microgram/0.1 ml, completely inhibited the cytoagglutination of the Ehrlich carcinoma cells caused by three agglutination doses (about 3 microgram/0.1 ml) of the R. japonica lectin.

Animals↗
PubMed1976

An anti-A-like lectin of Rana catesbiana eggs showing unusual reactivity.

A lectin was isolated from Rana catesbiana eggs that agglutinated blood group A-erythrocytes but did not agglutinate blood group B- or 0-erythrocytes. The lectin was purified by Sephadex G-75 gel filtration and by acrylamide gel electrophoresis at pH 4.3 and was proved to be homogeneous on electrophoresis, and the molecular weight was determined as 210 000. The specificity of A-like activity seems to direct towards three monosaccharide units: GalNAcalpha1 leads to 3(or 4)-Galbeta1 leads to 4(or 3)GlcNAcbeta1 leads to R based on inhibition of A-like hemagglutination by various monosaccharides, oligosaccharides and glycolipids, and based on precipitin reaction with various glycolipids and glycoproteins with known structures. Uniquely, A-like agglutination was inhibited not only by alpha-N-acetylgalactosamine analogs but also by N-acetyllactosamine analogs. The lectin showed therefore, two correlated specificities: one directed towards alpha-N-acetylgalactosamine residue at the terminal, and the other towards the subterminal Galbeta1 leads to 4betaGlcNAc (N-acetyllactosaminyl) residue. The reactivity due to the N-acetyllactosamine structure which is also found in erythrocyte ganglioside and in H-active chain might be blocked by sialyl or alpha-L-fucosyl substitution at the terminal, as the reactivity appeared after elimination of these sugar residues. In the A structure the reactivity due to N-acetyllactosaminyl residue seems not to be blocked by the presence of alpha-N-acetylgalactosamine at the terminal as A-agglutination was strongly inhibited by N-acetyllactosamine and its analogs. Although the lectin showed a single band on electrophoresis under different conditions, there is a possibility that the lectin may be a mixture of two proteins with different specificities as mentioned above.

ABO Blood-Group System↗
PubMedDate not supplied

Biguanides may produce hypoglycemic action in isolated rat hepatocytes through their effects on L-alanine transport.

We investigated the mechanisms of the effects of the biguanides metformin and buformin on hepatic gluconeogenesis in hepatocytes isolated from normal rats. Both 10 nM glucagon and 50 microM dibutyryl cAMP increased [3H]alanine uptake in isolated hepatocytes of normal rats by about 150% and 55%, respectively, compared with the effect of 5 mM alanine alone. Metformin (3 mM) reduced glucagon-stimulated [3H]alanine uptake to the level seen with alanine alone; buformin (3 mM) inhibited glucagon-stimulated [3H]alanine uptake by about 69%. The effects of biguanides on dibutyryl cAMP-stimulated [3H]alanine uptake were similar, but of smaller magnitude compared with those observed in the presence of glucagon. Ouabain (3 mM) had a stronger inhibitory effect on [3H]alanine uptake than the biguanides. However, 3 mM tolbutamide failed to suppress [3H]alanine uptake in the presence or absence of glucagon or dibutyryl cAMP. Our results suggest that the inhibition of alanine uptake, related to a reduction in the Na+/L-alanine transport system, is a possible mechanism of biguanide-related inhibition of hepatic gluconeogenesis.

Alanine↗