The blood group B type-4 heptaglycosylceramide is a minor blood group B structure in human B kidneys in contrast to the corresponding A type-4 compound in A kidneys. Structural and in vitro biosynthetic studies.

Blood group A glycolipid antigens have been found based upon at least four different core saccharides (types 1 to 4). The biological significance of this structural polymorphism is not known, although the successful outcome of transplantations of blood group A2 kidneys to blood group O individuals have been partly explained by the low expression of A type-3 and -4 chain glycolipid antigens in A2 kidneys. If graft rejection due to ABO incompatibility is, in any way, correlated to the expression of type-3 and -4 chain blood group glycolipids, it is of interest to identify possible blood group B structures based on these core saccharides. In a non-acid glycosphingolipid fraction isolated from human blood group B kidneys, mass spectrometry, high-temperature gas chromatography-mass spectrometry and probing of thin-layer chromatograms with Gal alpha 1-4Gal-specific Escherichia coli and monoclonal anti-B antibodies provided evidence for minute amounts of a Gal alpha 1-3(Fuc alpha 1-2)Gal beta-HexNAc-Gal alpha 1-4Gal beta-Hex-Ceramide structure consistent with a B type-4 chain heptaglycosylceramide. In contrast, blood group A kidneys have the corresponding A type-4 chain heptaglycosylceramide as the predominant blood group A glycolipid. No, or very low activity of the blood group B gene enzyme on the type-4 chain blood group H hexaglycosylceramide precursor was found by biosynthetic experiments in vitro, which might explain the low expression of type-4 chain blood group B heptaglycosylceramides in human blood group B kidneys.     

Blood group type glycosphingolipids of human kidneys. Structural characterization of extended globo-series compounds

Blood group type glycosphingolipids present in kidneys of blood group A and B human individuals have been isolated and structurally characterized by mass spectrometry, proton NMR spectroscopy, degradation studies and by their reactivity with various monoclonal antibodies andEscherichia coli bacteria. The two major complex glycolipids present in the blood group A and B kidneys were globopentaosylceramide (IV³Gal-Gb₄Cer) and the X pentaglycosylceramide (III³Fuc-nLc₄Cer). The major blood group A glycolipid in the blood group A kidneys was based on the type 4 chain (globo-series). There were also small amounts of the type 2 chain and trace amounts of the type 1 and type 3 chain based A glycolipids. In addition, the blood group H type 4 chain structure was present together with Le^a and Le^b compounds. In the blood group B kidneys, the major B glycolipids were monofucosylated hexa- and octaglycosylceramides, where the former were based on the type 2 carbohydrate chain. The blood group B type 4 chain heptaglycosylceramide was found to be a minor component making up only about 1% of the total blood group B structures. Abbreviations: for blood group glycolipid antigens the short hand designation stands for blood group—number of sugar residues—type of carbohydrate chain. Thus A-7-4 means a type 4 chain blood group A heptaglycosylceramide. The sugar types are abbreviated for mass spectrometry to Hex for hexose, HexNAc forN-acetylhexosamine and dHex for deoxyhexose.     

Structural characterization of non-acid glycosphingolipids in kidneys of single blood group O and A pigs

Total non-acid glycosphingolipids were isolated from the kidneys of single pigs serologically typed on their red blood cells as blood groups O and A. Glycolipid species were purified by HPLC and structurally characterized by thin-layer chromatography, mass spectrometry, proton NMR spectroscopy, degradation analysis, and reactivity with various monoclonal antibodies, Gal alpha 1-4Gal-specific E. coli bacteria, and lectins. Glucosyl-, globotriaosyl-, and globotetraosylceramides were the predominant molecular species with lactosyl- and globopentaosylceramides (IV3GalGb4Cer) as abundant constituents too. Small amounts of galactosyl- and digalactosylceramides were also present. In the blood group O pig kidneys, blood group H antigens based on four different core saccharides (types 1, 2, 4, and lactosyl core) were identified and the major blood group structure was V2FucIV3Gal-Gb4Cer. In the kidneys from the blood group A pig the corresponding blood group A antigens were found and in addition, a type 3 chain blood group A antigen was indicated by mass spectrometry and by its reactivity with a monoclonal antibody. Trace amounts of the type 2 chain-based X and Y antigens were found while blood group B antigens and the type 1 chain based Lewis antigens could not be detected. The ceramide part of the glycolipids was mainly composed of dihydroxy 18:0 long chain bases and non-hydroxy 16:0-24:0 fatty cids.     

Monoclonal antibody recognizing a determinant on type 2 chain blood group A and B oligosaccharides detects oncodevelopmental changes in azoxymethane-induced rat colon tumors and human colon cancer cell lines

Altered expression of ABH blood group substances is a common feature of human colorectal carcinoma, yet it remains unclear how these structural changes influence the biological properties of tumor cells. Azoxymethane-induced rat colon tumors display many features of the human disease, thereby providing a potentially useful model to study the role of blood group substances in colon cancer progression. We have prepared monoclonal antibodies to a microsomal fraction isolated from an azoxymethane-induced rat colon tumor and selected an antibody that detects cancer-associated changes. Monoclonal antibody (mAb) 3A7 recognizes a determinant on type 2 chain blood group A (GalNAcα1–3[Fucα1–2]Galβ1–4GlcNAc-R) and B (Galα1–3[Fucα1–2]Galβ1–4GlcNAc-R) oligosaccharides. Expression of the epitope detected by this antibody was developmentally regulated in rat colon, with maximal expression from day 4–21 after birth. Immunohistochemical staining and Western blotting analyses of azoxymethane-induced colon tumors revealed increased expression of the epitope in all of the 21 colonic tumors examined, including preneoplastic glands within transitional mucosa. Conventional and signet-ring adenocarcinomas that had invaded through the muscularis propria (Duke's B2) consistently showed the most intense staining with mAb 3A7, including regions depicting angioinvasion. Some of the lymph node metastases (Duke's C2) stained poorly with the antibody. The epitope was also expressed in blood group A positive human colon carcinoma cell lines, including HT29 and SW480 but not by SW620, a cell line derived from a lymph node metastasis isolated in vivo from the SW480 primary tumor, or in the blood group B cell line SW1417. The glycoproteins detected by mAb 3A7 in rat colon tumors and HT29 cells ranged in size between 50 and 200 kd, including a major species of 140 kd. Affinity chromatography of detergent lysates of normal rat colon on the blood group A specific lectin Dolichos biflorus (DBA)-agarose resulted in nearly quantitative binding of glycoprotein species detected by the antibody. By contrast, immunoreactive glycoproteins from rat colon tumors or HT29 cells bound poorly to DBA-agarose but were retained by another blood group A-binding lectin, Helix-pomatia (HPA)-agarose. These results indicate that colon carcinogenesis results in quantitative as well as qualitative changes in oligosaccharides detected by mAb 3A7 and suggest that the combined use of mAb 3A7 and blood group A-specific lectins may provide a useful tool for early detection of colon cancer.     

Glycolipid- and glycoprotein-based blood group A antigen expression in human thrombocytes. A1/A2 difference

Total non-acid glycolipid fractions and total sodium dodecylsulphate (SDS) solubilized protein fractions were isolated from human thrombocytes obtained from single human donors having different blood group A₁/A₂ phenotypes. The blood group A glycolipid antigens were characterized by immunostaining of thin layer plates with different monoclonal anti-A antibodies. The glycoproteins carrying blood group A epitopes were identified by SDS-PAGE and Western blot analysis using a monoclonal anti-A antibody. Blood group A glycolipid antigens were found in both A₁ and A₂ thrombocytes but the A₂ individuals expressed at least ten times less A glycolipids compared to the A₁ individuals. Expression of A type 3/4 chain and small amounts of A type 1 chain glycolipids were seen in thrombocytes of both A₁ and A₂ individuals, while the type 2 chain A glycolipids appeared to be missing from the A₂ thrombocytes. Blood group A reactive glycoproteins were only found in thrombocytes of A₁ individuals and could not be detected in A₂ individuals or a blood group O individual. The major blood group A glycoprotein were found as a double band migrating in the 130 kDa region.Abbreviations SDS sodium dodecyl sulfate - PAGE polyacrylamide gel electrophoresis - HPTLC high performance thin layer chromatography - CBB Coomassie brilliant blue - GVH graft versus host Part of this work was presented at the Xth International Symposium on Glycoconjugates, Jerusalem, Israel. September, 1989.In the short hand designation for glycolipids, the letter indicate blood group determinant, the first numeral, the number of sugar residues, and the second numeral, the type of carbohydrate chain. Thus, A-6-1 means a hexaglycosylceramide with a blood group A determinant based on the type 1 carbohydrate chain.     

ABO blood group system

The ABO blood group system in humans has three different carbohydrate antigens named A, B, and O. The A antigen sequence is terminal trisaccharide N-acetylgalactosamine (GalNAc)α1-3[Fucα1-2]Galβ-, B is terminal trisaccharide Galα1-3[Fucα1-2]Galβ-, and O is terminal disaccharide Fucα1-2Galβ-. The single ABO gene locus has three alleles types A, B and O. The A and B genes code A and B glycosyltransferases respectively and O encodes an inactive enzyme. A large allelic diversity has been found for A and B transferases resulting in the genetic subgrouping of each ABO blood type. Genes for both transferases have been cloned and the 3D structure of enzymes with and without substrate has been revealed by NMR and X ray crystallography. The ABO blood group system plays a vital role in transfusion, organ and tissue transplantation, as well as in cellular or molecular therapies.     

Blood group A glycolipid antigen expression in kidney, ureter, kidney artery, and kidney vein from a blood group A1Le(a-b+) human individual. Evidence for a novel blood group A heptaglycosylceramide based on a type 3 carbohydrate chain

Kidney, ureter, kidney artery, and kidney vein tissue were obtained from a single human transplant specimen. The donors erythrocyte blood group phenotype was A1Le(a-b+). Total non-acid glycolipid fractions were isolated and individual glycolipid components were identified by immunostaining thin layer plates with a panel of monoclonal antibodies and by mass spectrometry of the permethylated and permethylated-reduced total glycolipid fractions. The dominating glycolipids in all tissues were mono- to tetraglycosylceramides. In the kidney, ureter, and artery tissue less than 1% of the glycolipids were of blood group type, having more than 4 sugar residues. In contrast, 14% of the vein glycolipids were of blood group type, and the dominating components were type 1 chain blood group H pentaglycosylceramides and A hexaglycosylceramides. Trace amounts of structurally different blood group A glycolipids (type 1 to 4 core saccharide chains) with up to 10 sugar residues were found in the kidney, ureter, and vein tissues, including evidence for a novel blood group A heptaglycosylceramide based on the type 3 chain in the vein. The only detected A glycolipid antigen in the artery tissue was the blood group A difucosyl type 1 chain heptaglycosylceramide (ALeb) structure. Blood group Lewis and related antigens (Lea, Leb, and ALeb) were expressed in the kidney, ureter, and artery, but were completely lacking in the vein, indicating that the Le gene-coded alpha 1-4-fucosyltransferase was not expressed in this tissue. The X and Y antigens (type 2 chain isomers of the Lea and Leb antigens) were detected only in the kidney tissue.     

The biosynthesis of blood group B determinants by the blood group A gene-specified alpha-3-N-acetyl-D-galactosaminyltransferase

The blood group $\text{A}{}^1$ gene-specified α-3-N-acetyl-D-galactosaminyl-transferase in human plasma, when concentrated by adsorption onto group O red cell ghosts or Sepharose 4B, catalyses the transfer of D-galactose in α-linkage to low-molecular-weight H-active acceptors. The product synthesised with 2′-fucosyllactose is chromatographically indistinguishable from the blood group B-active tetrasaccharide, Galα1→3[Fucα1→2]Galβ1→4Glc. The optimum pH for the transfer of D-galactose by the $\text{A}{}^1$-transferase is 7. At this pH the V_max for the transfer of N-acetyl-D-galactosamine is about 300 times higher than that for the transfer of D-galactose. These results indicate that an $\text{A}{}^1$-transferase can, under centain conditions, synthesise B determinant structures.     

Tissue specificity of glycosphingolipids as expressed in pancreas and small intestine of blood group A and B human individuals

A chemical investigation has been done on blood group active glycosphingolipids of both small intestine and pancreas from two individuals, one blood group A and one blood group B. Total non-acid glycolipid fractions were prepared and the major blood group fucolipids present were purified and structurally characterized by mass spectrometry, proton NMR spectroscopy, and degradation methods. The glycolipid structures identified were a blood group Leb hexaglycosylceramide, a B-hexaglycosylceramide with a type 1 (Gal beta 1 leads to 3GlcNAc) carbohydrate chain, A-hexaglycosylceramides with types 1 and 2 (Gal beta 1 leads to 4GlcNAc) carbohydrate chains, a B-heptaglycosylceramide with a type 1 carbohydrate chain, and A-heptaglycosylceramides with type 1 and 2 carbohydrate chains. In addition several minor glycolipids having more than seven sugar residues were detected by thin-layer chromatography. The small intestine and pancreas had some distinct differences in their expression of the major fucolipids. The small intestine contained only glycolipids based upon type 1 carbohydrate chain while the pancreas had both type 1 and type 2 structures. The intestines contained mainly difucosyl compounds while the pancreas tissues contained both mono- and difucosyl glycolipids. Monofucosylglycolipids based on both types 1 and 2 saccharides were present in one pancreas while the other one contained only monofucosylcomponents based on type 1 chain. The ceramides of the intestinal glycolipids were found to be more hydroxylated (trihydroxy long-chain base, hydroxy fatty acids) compared to the pancreas glycolipids (dihydroxy long-chain base, non-hydroxy fatty acids).     

Chemical characterization of a blood group H type pentaglycosylceramide of human small intestine

A blood group H type pentaglycosylceramide was isolated in relatively large amounts from human adult small intestine (52mg from one individual) and human meconium (fetal origin). The structure was made likely by mass spectrometry and NMR spectroscopy of non-degraded permethylated and permethylated-LiAlH₄-reduced glycolipid and by degradaton to be Fucα1 → 2GAlβ 1 → 3GlcNAcβ 1 → 3GAlβ 1 → 4Glcβ 1 → l Cer. The ceramide was composed mainly of phytosphingosine and 2-hydroxy 16–24 carbon fatty acids. This novel type 1 chain species (Galβ 1 → 3GlcNAc) was not accompanied by the type 2 chain isomer (Galβ 1 → 4GlcNAc) which in contrast is the sole species in human erythrocyte and dog small intestine.     

Blood group A/B-defined glycosyltransferase and A/B blood group antigens in human normal and malignant endometrium in relation to morphology,age and oestrogen levels

We have used monoclonal antibodies to study the expression and regulation of A/B antigens and A/B transferase in normal and malignant human endometrium by immunohistochemistry. Staining was evaluated against blood group status, morphology, age ad serum oestrogen levels. The expression of the antigens, in contrast tothe expression of the transferase, was related to the A subtype (A₁/A₂) and the ABH secretor status. Normal, non-secretory endometria and most well-differentiated endometrial carcinomas from ABH secretors expressed the antigens and the transferase, but showed a morphology-dependent variation in the expression and degree of coexpression. n contrast, most grade 2 and 3 carcinomas were found to lack both structures, whereas secretory endometrium had a high expression of the transferase but expressed the antigens on only a few cells. The transferase expression was correlated inversely with age and positively with the level of free oestradiol in serum. Our findings suggest that A/B antigenic expression in the endometrium may be regulated at different levels — at the A/B transferase level and at a precursor substrate lvel — and that both genetic and hormonal factors are probably involved in the regulatory process.     

Blood group glycosphingolipid expression in kidney of an individual with the rare blood group A1 Le(a−b+) p phenotype: absence of blood group structures based on the globoseries

Total neutral glycolipid fractions were isolated from kidney and ureter tissue obtained at autopsy of an individual of the rare blood group A₁ Le(a–b+) p. The amount of glycolipids isolated were 3.7 and 2.5 mg g^–1 dry tissue weight for the kidney and ureter tissue, which is in the range of reference blood group P kidneys. Part of the kidney glycolipid fraction was subfractionated by HPLC. Glycolipid compounds were structurally characterized by thin-layer chromatography (chemical detection and immunostaining with monoclonal antibodies), proton NMR spectroscopy and mass spectrometry. Globotriaosyl- and globotetraosyl-ceramides, which are the major compounds in kidneys of P individuals, were absent in the p kidney, and a comparatively increased amount of monoglycosyland lactosylceramides was found. A shift to longer fatty acyl chains in the ceramide part of lactosylceramides was noted. Elongated globoseries compounds with five to seven sugar residues, including the blood group A type 4 chain structure, were lacking. A slight increase in neolactotetraosyl- and blood group X pentaglycosyl-ceramides was noticed. The study confirms an enzymatic block in the conversion of lactosylceramide to elongated globoseries compounds in the kidney tissue similar to that of erythrocytes of p individuals.Abbreviations: for blood group glycolipid antigens the short hand designation stands for: blood group — number of sugar residues — type of carbohydrate chain. Thus A-7-4 means a blood group A heptaglycoconjugate on a type 4 chain. The sugar types are abbreviated for mass spectrometry to Hex for hexose, HexNAc forN-acetylhexosamine and dHex for deoxyhexose. HPLC, high-performance liquid chromatography; HPTLC, high performance thin layer chromatography; EI, electron impact ionisation; LSI, liquid secondary ion; MS, mass spectrometry; NMR, nuclear magnetic resonance.     

Redefinition of the Carbohydrate Binding Specificity of Helicobacter pylori BabA Adhesin

Certain Helicobacter pylori strains adhere to the human gastric epithelium using the blood group antigen-binding adhesin (BabA). All BabA-expressing H. pylori strains bind to the blood group O determinants on type 1 core chains, i.e. to the Lewis b antigen (Fucα2Galβ3(Fucα4)GlcNAc; Le(b)) and the H type 1 determinant (Fucα2Galβ3GlcNAc). Recently, BabA strains have been categorized into those recognizing only Le(b) and H type 1 determinants (designated specialist strains) and those that also bind to A and B type 1 determinants (designated generalist strains). Here, the structural requirements for carbohydrate recognition by generalist and specialist BabA were further explored by binding of these types of strains to a panel of different glycosphingolipids. Three glycosphingolipids recognized by both specialist and generalist BabA were isolated from the small intestine of a blood group O pig and characterized by mass spectrometry and proton NMR as H type 1 pentaglycosylceramide (Fucα2Galβ3GlcNAcβ3Galβ4Glcβ1Cer), Globo H hexaglycosylceramide (Fucα2Galβ3GalNAcβ3Galα4Galβ4Glcβ1Cer), and a mixture of three complex glycosphingolipids (Fucα2Galβ4GlcNAcβ6(Fucα2Galβ3GlcNAcβ3)Galβ3GlcNAcβ3Galβ4Glcβ1Cer, Fucα2Galβ3GlcNAcβ6(Fucα2Galβ3GlcNAcβ3)Galβ3GlcNAcβ3Galβ4Glcβ1Cer, and Fucα2Galβ4(Fucα3)GlcNAcβ6(Fucα2Galβ3GlcNAcβ3)Galβ3GlcNAcβ3Galβ4Glcβ1Cer). In addition to the binding of both strains to the Globo H hexaglycosylceramide, i.e. a blood group O determinant on a type 4 core chain, the generalist strain bound to the Globo A heptaglycosylceramide (GalNAcα3(Fucα2)Galβ3GalNAcβ3Galα4Galβ4Glcβ1Cer), i.e. a blood group A determinant on a type 4 core chain. The binding of BabA to the two sets of isoreceptors is due to conformational similarities of the terminal disaccharides of H type 1 and Globo H and of the terminal trisaccharides of A type 1 and Globo A.     

Novel blood group H glycolipid antigens exclusively expressed in blood group A and AB erythrocytes (type 3 chain H). I. Isolation and chemical characterization

A series of blood group H antigens reacting with monoclonal antibody MBrl has been found in human blood group A and AB erythrocytes, but not in O or B erythrocytes. These H antigens are clearly different from the globo-H structure (Fuc alpha 1----2Gal beta 1----3GalNAc beta 1----3Gal alpha 1----4Gal beta 1----4Glc beta 1----1Cer), which was previously isolated from O erythrocytes and is also reactive with the MBrl antibody. The new series of H antigens associated with blood group A has been characterized as having TLC mobilities which approximately coincide with those of H2, H3, and H4 glycolipids. One of these A-associated H antigens, having a similar TLC mobility as the H2 glycolipid, was isolated from A erythrocytes and was characterized by 1H NMR spectroscopy, methylation analysis, and enzymatic degradation as having the structure shown below: (formula, see text). The structure represents a precursor of the repetitive A epitope attached to type 2 chain, previously called type 3 chain A (Clausen, H., Levery, S. B., Nudelman, E., Tsuchiya, S., and Hakomori, S. (1985) Proc. Natl. Acad. Sci. U.S.A. 82, 1199-1203). This A-associated H structure is hereby called type 3 chain H.     

Multivalent human blood group ABH and Lewis glycotopes are key recognition factors for a lFuc>Man binding lectin from phytopathogenic Ralstonia solanacearum

Ralstonia solanacearum lectin (RSL), that might be involved in phytopathogenicity, has been defined as lFuc?Man specific. However, the effects of polyvalency of glycotopes and mammalian structural units on binding have not been established. In this study, recognition factors of RSL were comprehensively examined with natural multivalent glycotopes and monomeric ligands using enzyme linked lectin-sorbent and inhibition assays. Among the glycans tested, RSL reacted strongly with multivalent blood group A_h (GalNAcα1–3[Fucα1–2]Gal) and H (Fucα1–2Gal) active glycotopes, followed by B_h (Galα1–3[Fucα1–2]Gal), Le^a (Galβ1–3[Fucα1–4]GlcNAc) and Le^b (Fucα1–2Galβ1–3[Fucα1–4]GlcNAc) active glycotopes. But weak or negligible binding was observed for blood group precursors having Galβ1–3/4GlcNAcβ1- (I_β/II_β) residues or Galβ1–3GalNAcα1- (T_α), GalNAcα1-Ser/Thr (Tn) bearing glycoproteins. These results indicate that the density and degree of exposure of multivalent ligands of α1–2 linked lFuc to Gal at the non-reducing end is the most critical factor for binding. An inhibition study with monomeric ligands revealed that the combining site of RSL should be of a groove type to fit trisaccharide binding with highest complementarity to blood group H trisaccharide (H_L; Fucα1–2Galβ1–4Glc). The outstandingly broad RSL saccharide-binding profile might be related to the unusually wide spectrum of plants that suffer from R. solanacearum pathogenicity and provide ideas for protective antiadhesion strategies.     

Chemical characterization of milk oligosaccharides of the polar bear, Ursus maritimus

Two trisaccharides, three tetrasaccharides, two pentasaccharides, one hexasaccharide, one heptasaccharide, one octasaccharide and one decasaccharide were isolated from polar bear milk samples by chloroform/methanol extraction, gel filtration, ion exchange chromatography and preparative thin-layer chromatography. The oligosaccharides were characterized by ¹H-NMR as follows: the saccharides from one animal: Gal(α1-3)Gal(β1-4)Glc (α3′-galactosyllactose), Fuc(α1-2)Gal(β1-4)Glc (2′-fucosyllactose), Gal(α1-3)[Fuc(α1-2)]Gal(β1-4)Glc (B-tetrasaccharide), GalNAc(α1-3)[Fuc(α1-2)]Gal(β1-4)Glc (A-tetrasaccharide), Gal(α1-3)Gal(β1-4)GlcNAc(β1-3)Gal(β1-4)Glc, Gal(α1-3)[Fuc(α1-2)]Gal(β1-4)GlcNAc(β1-3)Gal(β1-4)Glc, Gal(α1-3)Gal(β1-4)GlcNAc(β1-3)[Gal(α1-3)Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc; the saccharides from another animal: α3′-galactosyllactose, Gal(α1-3)Gal(β1-4)[Fuc(α1-3)]Glc, A-tetrasaccharide, GalNAc(α1-3)[Fuc(α1-2)]Gal(β1-4)[Fuc(α1-3)]Glc (A-pentasaccharide), Gal(α1-3)Gal(β1-4)[Fuc(α1-3)]GlcNAc(β1-3)Gal(β1-4)Glc, Gal(α1-3)Gal(β1-4)[Fuc(α1-3)]GlcNAc(β1-3)Gal(β1-4)[Fuc(α1-3)]Glc (difucosylheptasaccharide) and Gal(α1-3)Gal(β1-4)[Fuc(α1-3)]GlcNAc(β1-3){Gal(α1-3)Gal(β1-4)[Fuc(α1-3)]GlcNAc(β1-6)}Gal(β1-4)Glc (difucosyldecasaccharide). Lactose was present only in small amounts. Some of the milk oligosaccharides of the polar bear had α-Gal epitopes similar to some oligosaccharides in milk from the Ezo brown bear and the Japanese black bear. Some milk oligosaccharides had human blood group A antigens as well as B antigens; these were different from the oligosaccharides in Ezo brown and Japanese black bears.     

Glycosphingolipids of human large intestine: detailed structural characterization with special reference to blood group compounds and bacterial receptor structures

Non-acid glycosphingolipid expression was studied in the large intestines from four individuals with the A1Le(a-b+), BLe(a-b+), and OLe(a-b+) blood group phenotypes. In the A1Le(a-b+) case, specimens were taken from the ascending and sigmoid parts of the large intestine in order to compare the expression of glycolipids in the proximal and distal regions of the intestine. In one blood group OLe(a-b+) individual, epithelial cells were isolated from the residual stroma to compare the glycolipid compositions in these two tissue compartments. GlcCer, GalCer, LacCer, Gb3Cer, and Gb4Cer were the major compounds in all three individuals, as shown by mass spectrometry, proton NMR spectroscopy, and degradation studies. The Lea-5 glycolipid was the major complex blood group glycolipid in all individuals, except in the proximal ascending part of the large intestine of the A1Le(a-b+) case, in which the Leb-6 glycolipid was predominant. There were trace amounts of blood group ABH glycolipids, in agreement with the ABO blood group phenotypes of the donors, Lewis antigens with more than six sugar residues in the carbohydrate chain, and blood group X and Y glycolipid antigens. The epithelial cells were dominated by monoglycosylceramides and the Lea-5 glycolipid, while only trace amounts of di-, tri-, and tetraglycosylceramide structures were present. No reactivity was seen in the epithelial cell fraction with Gal alpha 1-4Gal specific Escherichia coli, anti-Pk, or anti-P antibodies, indicating the absence of the glycolipid-borne Gal alpha 1-4Gal sequence in human large intestinal epithelial cells.     

Structural characterization of a blood group A heptaglycosylceramide with globo-series structure. The major glycolipid based blood group A antigen of human kidney

A blood group A glycosphingolipid with the globo-series structure has been isolated from human kidney and structurally characterized. The structure was shown by mass spectrometry and proton NMR spectroscopy of the intact permethylated and permethylated-reduced derivatives together with degradation studies to be, GalNAc alpha 1----3Gal(2----1 alpha Fuc)beta 1----3GalNAc beta 1----3Gal alpha 1----4Gal beta 1----4Glc beta 1----1 Ceramide. This glycolipid reacts with both polyclonal and monoclonal anti-A blood group typing antisera and it is the major glycolipid based blood group A antigen present in the human kidney.     

Human erythrocyte P and Pk blood group antigens: identification as glycosphingolipids

The human erythrocyte P blood group system consists of three known antigens, P₁, P and P^k. We have identified the P antigen as the glycosphingo-lipid globoside, βGalNAc(1→3)αGal(1→4)βGal(1→4)Glc-cer, and the P^k antigen as ceramide trihexoside, αGal(1→4)βGal(1→4)Glc-cer. These data suggest, in contrast to previous hypotheses, that the P^k antigen is a biosynthetic precursor of P, and that neither P nor P^k is a precursor of P₁. These findings also provide an explanation for the apparent recessive inheritance of the P^k antigen, and for the nature of the biochemical abnormality in individuals of the rare P^k and p phenotypes.     

Design of the blood group AB glycotope

Although the nature of the blood groups A and B has been comprehensively studied for a long time, it is still unclear as to what exactly is the epitope that is recognized by antibodies having AB specificity, i.e. monoclonal and polyclonal antibodies which are capable of interacting equally well with the antigens GalNAcα 1-3(Fucα 1-2)Gal (A trisaccharide) and Galα 1-3(Fucα 1-2)Gal (B trisaccharide), but do not react with their common fragment Fucα 1-2Gal. We have supposed that besides Fucα 1-2Gal, A and B antigens have one more shared epitope. The trisaccharides A and B are practically identical from the conformational point of view, the only difference being situated at position 2 of Galα residue, i.e. trisaccharide A has a NHAc group, whereas trisaccharide B has a hydroxyl group (see formulas). We have hypothesized that the AB-epitope should be situated in the part of the molecule that is opposite to the NHAc group of GalNAc residue. In order to test this hypothesis we have synthesized a polymeric conjugate in such a way that de-N-acetylated A-trisaccharide is attached to a polymer via the nitrogen in position C-2 of the galactosamine residue. In this conjugate the supposed AB-epitope should be maximally accessible for antibodies from the solution, whereas the discrimination site of antigens A and B by the antibodies should be maximally hidden due to the close proximity of the polymer. Interaction with several anti-AB monoclonal antibodies revealed that a part of them really interacted with the synthetic AB-glycotope, thus confirming our hypothesis. Moreover, similar antibodies were revealed in the blood of healthy blood group 0 donors. Analysis of spatial models was performed in addition to identify the hydroxyl groups of Fuc, Galα, and Galβ residues, which are particularly involved in the composition of the AB-glycotope. Published in 2005.