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Biomedical subjects

J Kościelak

Publications and source records attributed to J Kościelak.

At least 19 recordsLinked to original sources
PubMed1992

Ganglioside binding proteins of calf brain with ubiquitin-like N-terminals.

Two ganglioside-associated protein components I and II have been isolated from crude ganglioside preparations of calf brain by DEAE-Sephadex ion-exchange chromatography. Both components exhibited binding capacity in aqueous media for gangliosides of the 'ganglio' series but not for neutral glycosphingolipids (polyglycosylceramides) and only a low capacity for sialosylparagloboside. Each protein bound individual gangliosides with different efficiency. Upon prolonged incubation of component I with gangliosides, complexes with high (30:1) and low (6:1) glycolipid/protein molar ratios were formed. The latter but not the former complex was able to penetrate Sephadex G-200 beads. Both components inhibited plating efficiency of cultured mouse N2a neuroblastoma cells. The molecular masses of components I and II were determined by SDS/PAGE to be 11-12 kDa and 28 kDa, respectively. Carbohydrates (fucose, mannose, galactose, N-acetylglucosamine, N-acetylgalactosamine, and some sialic acid) were found only in component II. When examined by reverse-phase HPLC each component separated into two major closely migrating peaks which were subsequently examined by Edman degradation. Amino acid sequences of the N-terminal portions of three of these peaks (one peak from component I and both peaks from component II) showed, as far as the sequences were established, identity with the sequence of ubiquitin. It is hypothesized that the proteins may be instrumental in intracellular trafficking of gangliosides.

Amino Acid Sequence↗
PubMed1989

Characterization and quantitation of fatty acids covalently bound to erythrocyte membrane proteins: anion transporter contains 1 mol of fatty acid thiol ester.

Human erythrocyte membranes which had been thoroughly extracted with organic solvents contained 20 nmol of fatty acids/mg dry wt. The major fatty acids were palmitic and stearic with their monoethenoic derivatives as minor constituents. No other fatty acids were detected. When solvent-extracted membranes were digested with Pronase about 90% of the original content of fatty acids was retained in the insoluble residue. Fatty acids were linked to membrane proteins through alkali-labile bonds of which 30% were of a thiol ester and the remainder of an O-ester type. This conclusion is based on differential liberation of fatty acids by hydroxylamine at pH 7.0 and pH 11.0. Two extracts of membranes enriched in peripheral proteins (bands 1, 2, 5 and 2.1, 4.1, 4.2, 6) were prepared and extracted with organic solvents but each contained about six times less fatty acids than the parent solvent-extracted membranes. Glycophorin A contains little if any covalently bound fatty acids. Anion transporter (band 3) contains about 1 mol of thiol ester of fatty acid. This accounts for about half of the thiol ester-linked fatty acids in the parent solvent-extracted membranes. Most of the O-ester-linked fatty acids are linked to an undisclosed membrane protein.

Anion Transport Proteins↗
PubMed1989

Human platelets release alpha-6-L-fucosyltransferase upon activation.

Previously we have shown that human platelets release alpha-6-L-fucosyltransferase (EC 2.4.1.68) during coagulation of blood [(1987) Glycoconjugate J. 4, 43-49]. Here we report that agonists which induce platelet aggregation bring about release of the enzyme. In quantitative terms the release of alpha-6-L-fucosyltransferase by washed, aggregated platelets was very similar to that occurring during blood coagulation.

Adenosine Diphosphate↗
PubMed1987

Glycolipids and glycopeptides of red cell membranes in congenital dyserythropoietic anaemia type II (CDA II).

The composition and structure of neutral and acidic oligoglycosylceramides, polyglycosylceramides and polyglycosylpeptides were determined in erythrocyte membranes of two patients with congenital dyserythropoietic anaemia type II. In keeping with previous studies we found an elevated accumulation in CDA II erythrocytes of LacCer, Lc3Cer and nLc4Cer. Gb4Cer was elevated in erythrocytes of only one of the two patients tested. In addition we found a significant increase of 6IVNeuAcnLc4Cer ganglioside. Polyglycosylceramides were elevated 6-fold but they resembled those of cord erythrocytes with respect to complexity and the number of side chains. Polyglycosylpeptides of CDA II erythrocytes were decreased 7-fold. These glycopeptides were, however, heterogeneous with respect to branching pattern; the minor fraction was highly branched whereas the major one was more linear in structure. Both polyglycosylceramides and polyglycosylpeptides exhibited high I and i antigenicity. We postulate that the accumulation of glycolipids and underglycosylation of glycoproteins in CDA II membranes results from the prolongation of G1 and possibly M phases of the mitotic cycle of the erythroid cells in which glycolipids are preferentially synthesized.

Adult↗
PubMed1986

Structure of a new disialoganglioside GD1c from spontaneous murine thymoma.

A major mono- and a di-sialoganglioside were isolated and purified to homogeneity from a spontaneous thymoma that occurs in AKR mice. Compositional and methylation analyses and the use of exoglycosidases established the monosialoganglioside to be alpha Neu(2----3)beta Gal(1----3)beta GalNAc(1----4)beta Gal(1----4)Glc(1----4)Cer and the disialoganglioside to be alpha NeuAc(2----8)alpha NeuAc(2----3)beta Gal(1----3)beta GalNAc(1----4)beta Gal(1----4)Glc(1----1)Cer (GD1c). A possible pathway for the biosynthesis of this disialoganglioside is presented.

Animals↗
PubMed1986

Weak A phenotypes possibly caused by mutation.

A family is described in which an apparent Ay phenotype was transmitted through 2 generations. We favor a mutation of the A allele as the most likely cause of the phenotype. Activities of the serum A-gene-specified transferase were not detected in any of the 3 family members with the Ay phenotypes.

ABO Blood-Group System↗
PubMed1986

A possible biological function of carbohydrate structures which are typical of erythrocytes.

Carbohydrates of erythrocyte glycoconjugates seem to be specifically designed so that they do not appreciably interact with other types of cells or ligands. This applies to glycosphingolipids (GSLs) and glycoproteins (GPs). An important distinction between the two types of glycoconjugates seems to be that GPs, apart from carrying carbohydrates, have some biological function which is most likely associated with their protein moieties. GSLs of erythrocytes, including the ABH, PP1 and Pk blood group substances, are viewed as energetically cheap membrane-packing substances filling in the membrane areas not covered by functional GPs. Their sole function should be the formation of inert carbohydrate protective layer at the membrane. The role of the inert carbohydrate structures in the development, tumorigenesis and evolution of blood group polymorphism is discussed.

Animals↗
PubMed1979

Immunochemistry of Ii-active glycosphingolipids of erythrocytes.

Fractions of complex glycosphingolipids were prepared from adult, cord, and i phenotype erythrocytes by the method elaborated for the isolation of poly(glycosyl)ceramides. In contrast to poly(glycosyl)ceramides which comprise on the average 30 glycosyl units and about 5 branching points, i.e. 3,6-di-O-substituted galactopyranosyl residues, per mole of glucose, complex glycosphingolipids from cord and i erythrocytes comprise 6 and 15 glycosyl units respectively and only 0.7 branching points. The latter substances exhibited also a high i activity which was not detected in poly(glycosyl)ceramides. Erythrocyte membranes were labeled with radioactive N-acetylgalactosamine (GalNAc) from UDP-GalNAc using a purified A-blood-group gene-specified transfered of GalNAc. It was found that electrophoretic mobilities in dodecylsulfate-gel electrophoresis of all glycoconjugates which accepted GalNAc were increased in i as compared to I membranes. We conclude that the absence of highly branched glycosphingolipids in cord and i erythrocytes as well as the reduction of apparent molecular weights of the glycoconjugates, which are substrates for A-gene-specified transferase of GalNAc, result from a single cause, that is an inadequacy of the biosynthetic process which is responsible for the formation of GlcNAc1 leads to 6Gal structures.

Adult↗
PubMed1978

Studies on the structure and I-blood-group activity of poly(glycosyl)ceramides.

Employing a modified technique of acetolysis, which allows almost a complete recovery of constituent sugars from poly(glycosyl)ceramides, the glycolipids were found to contain an excess of N-acetylglucosamine over galactose. On the basis of Smith degradation, methylation study, chromium trioxide degradation and the structures of oligosaccharides released from the glycolipids by partial acid hydrolysis, the presence of two types of sugar sequences has been established in poly(glycosyl)ceramides: a) Galbeta1 leads to 4GlcNAcbeta1 leads to 6Gal3 comes from R1 b) Galbeta1 leads to 4GlcNAcbeta1 leads to 4GlcNAc1 leads to R2. The repeating unit of poly(glycosyl)ceramides seems to be the GlcNAcbeta1 leads to 3Gal sequence. The specificity of one anti-I serum (Woj) is directed against the non-reducing ending of the first kind of chain. Three other anti-I sera reacted with inner portions of the oligosaccharide chains of the glycolipids.

Blood Group Antigens↗
PubMed1978

Structures and fatty acid compositions of neutral glycosphingolipids of human plasma.

Major neutral glycosphingolipids were isolated from human plasma and their structures and fatty acid compositions studied. The four neutral glycosphingolipids of plasma were characterized as Glc beta(1 leads to 1)ceramide, Gal beta(1 leads to 1)- ceramide, Gal beta(1 leads to 4) Glc beta (1 leads to 1)ceramide, Gal alpha(1 leads to 4) Gal beta(1 leads to 4) Glc beta(1 leads to 1)ceramide and GalNAc beta(1 leads to 3) Gal (1 leads to 4) Gal (1 leads to 4) Glc beta(1 leads to 1)-ceramide. The glycosphingolipids contained mostly short chain fatty acids of which most prominent was C16. Erythrocyte glucosylceramide and lactosylceramide exhibited similar fatty acid compositions as their plasma counterparts. Triglycosylceramide and globoside of erythrocytes contained almost exclusively long-chain fatty acids. In lactosylceramide obtained from "p" erythrocytes, an accumulation of long-chain fatty acids was found; this accumulation was not observed, however, in lactosylceramide isolated from "p" plasma. It was concluded that plasma and erythrocyte glycosphingolipids are synthesized at separate sites where short- and long-chain fatty acids, respectively, are available. Plasma and erythrocyte glucosylceramide, and probably a fraction of lactosylceramide, exchange between plasma and erythrocyte pools. The latter conclusion is discussed in the light of the relative roles of carbohydrate and lipid moieties of the glycosphingolipids in maintaining their association with erythrocyte membranes.

Erythrocyte Membrane↗
PubMed1978

Enzymatic synthesis of H-active pentaglycosylceramide by human bone marrow fucosyltransferase.

Synthesis of two fucoglycolipides I and II was obtained from GDP-fucose and lacto-N-neotetraosylceramide using either solubilized or particulate enzymic preparation from human bone marrow. Fucoglycolipid I on the basis of its chromatographic mobility and immunoprecipitation with Ulex europeus lectin was identified as H blood group active penta glycosylceramide. Fucoglycolipid II did not react with Ulex europeus and its fucosyl residue was hydrolyzed by alpha (1 leads to 3/4)-L-fucosidase of Trichomonas fetus. Most probably the fucose residue of glycolipid II was linked to N-acetyloglucosamine by 1 leads to 3 linkage.

ABO Blood-Group System↗