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Biomedical subjects

V Horejsí

Publications and source records attributed to V Horejsí.

At least 91 records · Page 5Linked to original sources
PubMed1984

The use of lectins for determination of absolute configurations of small amounts of sugars eluted from chromatograms.

A simple procedure for the determination of the absolute configuration (i.e., assignment to the D- or L-enantiomeric series) of glucose, mannose, galactose, fucose, arabinose, and rhamnose is described, based on inhibition by these sugars of 125I-labeled lectin binding to the glycoconjugates immobilized on the wells of plastic microculture plates. The method works well with 10 to 100-micrograms amounts of the sugars isolated after paper chromatography of the glycoprotein or polysaccharide hydrolysates.

Chemical Phenomena↗
PubMed1984

Murine hybridoma monoclonal antibodies against insulin: cross-reactivity with insulins of three species and blocking of insulin binding to its receptor.

Six hybridoma cell lines secreting monoclonal antibodies against pig insulin and cross-reacting with human and bovine insulins were obtained. Five of these monoclonal antibodies were IgG1, kappa, one IgG2b, kappa; their pI values were in the range of pH 6.3-7.4 and dissociation constants of the insulin-antibody complexes were 0.3-2 X 10(-8) mol/l, as determined by an immunoradiometric inhibition assay. All of these antibodies reacted with sterically closely related determinants and blocked the binding of 125I-pig insulin to the receptor on human MOLT-4 cell line.

Animals↗
PubMed1984

Cross-reactivity between tubulin and denatured human serum albumin demonstrated by monoclonal antibody TU-01.

Murine monoclonal antibody TU-01 specific for tubulin (Viklický et al., 1982, Cell. Biol. Int. Rep. 6, 725; Dráber et al., in prep.) also recognizes a determinant in denatured reduced human serum albumin and in some peptides produced by its partial enzymatic cleavage, but does not react with serum albumins of several other species tested. Several other anti-tubulin monoclonal antibodies do not exhibit such a cross-reactivity.

Animals↗
PubMed1984

The use of murine monoclonal antibody B2M-01 for detection and purification of human beta 2-microglobulin.

A murine hybridoma cell line was obtained producing monoclonal antibody specific for human beta 2-microglobulin (beta 2m). The antibody reacts strongly with cell-associted human beta 2m, weakly with the cells of the monkey Cercopithecus aethiops, but not with any other non-primate cells tested. It is of IgG2a isotype, its pI is 6.9-7.1 and dissociation constant of its complex with soluble beta 2m is K = 1.5 X 10(-8) mol/l. The antibody also binds to beta 2m after electrophoretic separation under the reducing and denaturating conditions and blotting onto nitrocellulose. Immobilization of this antibody on Sepharose 4B yields an efficient immunosorbent for purification of beta 2m.

Antibodies, Monoclonal↗
PubMed1984

Production and characterization of monoclonal antibodies against human transferrin.

Twenty-one hybridoma lines were established, producing monoclonal antibodies against human transferrin and growing well in the peritoneal cavity of the mouse. Eight of these monoclonal antibodies were characterized. All of them are of IgG1 subclass with K light chains. The only human serum protein recognized by these antibodies is transferrin. Individual antibodies and their pairs do not precipitate the antigen, whereas 5 of their triads yield sharp precipitation lines with human transferrin. These results indicate that different monoclonal antibodies of this series recognize different epitopes on the transferrin molecule and that these antibodies or their mixtures can be employed in binding and precipitation tests.

Animals↗
PubMed1983

Adult transplantation tolerance induced by lentil lectin. III. Induction of transplantation tolerance by lentil lectin in mouse strain combinations with different H-2 disparities: tolerogenic effect of H-2D region antigens.

The survival time of skin allografts was investigated in 28 combinations of mouse strains differing at various loci, in adult recipients treated with lentil seed lectin (LCA). The recipients were given 1 mg of LCA daily (i.v. or i.p.) after transplantation of the skin graft. The immunosuppressive effect of LCA was generally inversely related to the conventional strength of the allotransplantation reaction, i.e. the rate of rejection of allografts on untreated recipients. In the case of H-2D antigenic disparities, the grafts usually survived for more than 100 days. The H-2A or H-2K disparity appeared to be relatively resistant to induction of tolerance by LCA treatment. The relative resistance of various H-2 antigens toward the induction of tolerance by LCA differs to some extent from that observed in experiments on the induction of neonatal tolerance by semiallogeneic lymphocytes as described in literature.

Animals↗
PubMed1983

Adult transplantation tolerance induced by lentil lectin. I. The fate of tolerogenic lentil seed lectin after injection into mice.

Intravenous administration of lentil lectin is more efficient in the induction of transplantation tolerance to mouse skin allograft than intraperitoneal or subcutaneous administration. 131I-labelled LCA is eliminated relatively rapidly from the mouse body after i.v. injection (approximately 80% of a 1 mg dose eliminated after 48 h); LCA administered i.p. or s.c. is eliminated 2-3 times more slowly. The rate of elimination of LCA administered i.v. is only slightly lower than that of bovine serum albumin. Tolerogenic treatment by multiple i.p. or i.p. + i.v. doses of LCA only elicited a relatively low level of anti-LCA antibodies in the sera of recipients. Both LCA and BSA were distributed relatively homogeneously throughout the body but increased amounts of LCA were accumulated in the spleen, lymph nodes and lung.

Animals↗
PubMed1980

Studies on lectins. XLVII. Some properties of D-galactose binding lectins isolated from the seeds of Butea frondosa, Erythrina indica and Momordica charantia.

The lectins from the seeds of Butea frondosa, Erythrina indica and Momordica charantia were isolated by affinity chromatography on O-alpha-D-galactosyl polyacrylamide gels. The Butea frondosa lectin has sedimentation coefficient S20,W = 6.7 S, its molecular weight is 141 000 and it consists of noncovalently associated subunits of molecular weights 36 000 and 65 000. The lectin contains two 1/2-cystine and 3--4 methionine residues per molecule, 4.3% neutral sugar and 0.5% glucosamine. Threonine is the single N-terminal amino acid residue. The lectin from Erythrina indica seeds has a sedimentation coefficient S20,W = 4.0 S, its molecular weight is 66 200 and it consists of two kinds of subunit (molecular weights 30 000 and 34 000, respectively), which are noncovalently associated. The lectin is devoid of cystein, has a neutral sugar content 5.6% and glucosamine content 0.46%. It contains probably one Mn atom per subunit. The N-terminal amino acid sequence is Val-Glu-Val-Leu-(Phe)-Phe-(Ala)-Phe-. The lectin from Momordica charantia seeds has a sedimentation coefficient S20,W = 6.5 S, its molecular weight is 129 000. It interacts weakly with Sephadex G-200. The lectin consists of subunits of molecular weights 29 000, 32 000 and 36 000, respectively, held together by cystine bridges. Its content of cystine and methionine residues is relatively high, 4.1% neutral sugar and 0.5% glucosamine form the carbohydrate moiety. Two N-terminal amino acids (asparagine and valine) are present.

Amino Acids↗
PubMed1980

Lentil lectin effectively induces allotransplantation tolerance in mice.

The interaction of lectins with carbohydrate receptors on the plasma membrane of eukaryotic cells results in a wide variety of biological effects. One effect which has been extensively studied is the stimulation of lymphocytes to blastogenesis and proliferation. High doses of concanavalin A (Con A) and phytohaemagglutinin (PHA) have been shown to activate in vitro regulatory cells capable of suppressing proliferation of other cells in the culture. However, Con A and PHA treatment were used effectively to prolong the survival of skin and heart allografts before it was recognised that some lectins have an activatory effect on suppressor cells in vitro. A possible explanation of these tolerogenic effects is the activation of specific suppressor cells. In this letter we have compared systematically various lectins differing in their carbohydrate specificity and mitogenicity in relation to their ability to induce prolonged skin allograft survival in mice with the aim of selecting the most effective lectin tratment schedule. Some preliminary results of this study have been mentioned in a recent review.

Animals↗
PubMed1979

Galactose oxidase. An enzyme with lectin properties.

Galactose oxidase interacts with immobilized D-galactosyl residues and related immobilized and free sugars under the conditions of affinity electrophoresis in polyacrylamide gel and agglutinates sialidase-treated human erythrocytes. The agglutination is also inhibited by D-galactose and its derivatives and is temperature dependent. The sugar binding and hemagglutinating activity are preserved after removal of Cu2+ essential for enzymic activity. These properties are very similar to those of some typical lectins; however, a number of D-galactose specific lectins do not possess any detectable galactose oxidase activity.

Carbohydrate Metabolism↗
PubMed1979

Properties of Ulex europaeus II lectin isolated by affinity chromatography.

A lectin was isolated from Ulex europaeus seeds by affinity chromatography on affinity adsorbent prepared by copolymerization of acrylamide, N,N'-methylene bisacrylamide and maleylated hog stomach peptone. The lectin is homogeneous as judged by ultracentrifugation (s20,w = 6.4 S), electrophoretic and gel chromatography criteria; it contains 4.2% neutral sugar and 1.4% glucosamine. Its molecular weight is approx. 110,000 and the molecule consists of two noncovalently linked protomers which are formed by two covalently bound basic subunits (Mr = 30,000). The preparation contains three isolectins differing in the strength of interaction with specific sugars (cellobiose, N-acetyl-D-glucosamine) under the conditions of affinity electrophoresis. The lectin is non-specific with human ABO blood group system, the agglutination is inhibited by partial chitin hydrolysate, hog stomach peptone and high concentration of cellobiose.

Amino Acids↗
PubMed1979

Studies on lectins. XLIV. The pH dependence of lectin interactions with sugars as determined by affinity electrophoresis.

The pH dependence of association constants of the lectin-sugar complexes was determined by means of affinity electrophoresis. All the lectins studied (from the seeds of Dolichos biflorus, Glycine soja, Lens esculenta and Vicia cracca and of the fruiting body of Marasmius oreades) were characterized by a similar course of pH dependence of the association constants, with the maximum values at pH 7--9. For concanavalin A and the L-fucose binding Ulex europaeus lectin only the association constants at three selected pH values were determined. Concanavalin A does not interact with immobilized alpha-D-mannosyl residues at pH 2.3. The association constants vs. pH curves measured for lectins isolated from two different lentil varieties slightly differ in accordance with the differences observed in the interaction of these lectins with the Sephadex gel.

Binding Sites↗