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| 2. |
- Bengtson, Per, et al.
(författare)
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Identification of a Missense Mutation (G329A; Arg110→ Gln) in the Human FUT7 Gene
- 2001
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Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 276:34, s. 31575-31582
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Tidskriftsartikel (refereegranskat)abstract
- The human FUT7 gene codes for the α1,3-fucosyltransferase VII (Fuc-TVII), which is involved in the biosynthesis of the sialyl Lewis x (SLex) epitope on human leukocytes. The FUT7 gene has so far been considered to be monomorphic. Neutrophils isolated from patients with ulcerative colitis were examined for apparent alterations in protein glycosylation patterns by Western blot analysis using monoclonal antibodies directed against SLex and SLex-related epitopes. One individual showed lower levels of SLex expression and an elevated expression of CD65s compared to controls. The coding regions of the FUT7 gene from this individual were cloned, and a G329A point mutation (Arg110 → Gln) was found in one allele, whereas the other FUT7 allele was wild type. No Fuc-TVII enzyme activity was detected in COS-7 cells transiently transfected with the mutated FUT7 construct. TheFUT7 Arg110 is conserved in all previously cloned vertebrate α1,3-fucosyltransferases. Polymerase chain reaction followed by restriction enzyme cleavage was used to screen 364 unselected Caucasians for the G329A mutation, and a frequency of ≤1% for this mutation was found (3 heterozygotes). Genetic characterization of the family members of one of the additional heterozygotes identified one individual carrying the G329A mutation in both FUT7alleles. Peripheral blood neutrophils of this homozygously mutated individual showed a lowered expression of SLex and an elevated expression of CD65s when analyzed by Western blot and flow cytometry. The homozygous individual was diagnosed with ulcer disease, non-insulin-dependent diabetes, osteoporosis, spondyloarthrosis, and Sjögren's syndrome but had no history of recurrent bacterial infections or leukocytosis.
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| 3. |
- Bengtson, Per, et al.
(författare)
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Polymorphonuclear Leukocytes from Individuals Carrying the G329A Mutation in the α1,3-Fucosyltransferase VII Gene (FUT7) Roll on E- and P-Selectins
- 2002
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Ingår i: Journal of Immunology. - 0022-1767 .- 1550-6606. ; 169:7, s. 3940-3946
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Tidskriftsartikel (refereegranskat)abstract
- We recently identified several individuals carrying a missense mutation (G329A; Arg110-Gln) in the FUT7 gene encoding fucosyltransferase VII. This enzyme is involved in the biosynthesis of the sialyl Lewis x (Lex) epitope on human leukocytes, which has been identified as an important component of leukocyte ligands for E- and P-selectin. No enzyme activity was measurable in expression studies in COS-7 cells using the mutated FUT7 construct. One of the identified individuals carried this mutation homozygously. Flow cytometry analysis of polymorphonuclear leukocytes (PMN) from this individual showed a nearly complete absence of staining with mAbs directed against sialyl Lex and a diminished staining with an E-selectin IgG chimera. However, staining with P-selectin IgG chimera and Abs directed against P-selectin glycoprotein ligand-1 was not affected by the mutation. PMN from the homozygously mutated individual was further analyzed in an in vitro flow chamber assay. The number of rolling PMN and the rolling velocities on both E- and P-selectin were in the range of PMN from nonmutated individuals. FUT4 and FUT7 mRNA was quantified in PMN isolated from individuals carrying the FUT7 mutation. It was found that PMN from both FUT7 homozygously and heterozygously mutated individuals exhibited an elevated expression of FUT4 mRNA compared with PMN from FUT7 nonmutated individuals. The elevated expression of fucosyltransferase IV was reflected as an increased expression of the Lex and CD65s Ags on PMN from these individuals. The significance of the mutation was supported by transfection of BJAB cells.
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| 5. |
- Chester, Alan, et al.
(författare)
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Biosynthesis of the blood-group-B-specific trisaccharide in a rhesus monkey
- 1977
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Ingår i: European Journal of Biochemistry. - 0014-2956. ; 77:1, s. 87-91
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Tidskriftsartikel (refereegranskat)abstract
- A Rhesus monkey, serologically grouped as B, has been shown to excrete low-molecular-weight carbohydrate material in urine closely related to that found in human urine. Galactose feeding resulted in the excretion of a trisaccharide which was shown to be identical to the trisaccharide isolated from the urine of group B humans under the same conditions. Experiments in which [14C]galactose was administered both orally and via an intestinal vein demonstrated that the intestine is the site of biosynthesis.
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| 6. |
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| 7. |
- Chester, Alan, et al.
(författare)
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Urinary excretion of oligosaccharides induced by galactose given orally or intravenously
- 1979
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Ingår i: European Journal of Biochemistry. - 0014-2956. ; 100:2, s. 385-392
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Tidskriftsartikel (refereegranskat)abstract
- The effect of oral administration of galactose, lactose, and sucrose and intravenous injection of galactose on the urinary excretion of blood-group-active oligosaccharides has been studied. Galactose given either as the free sugar, a glycoside (lactose) or a constituent of normal diet was an absolute requirement for the formation and excretion of A-trisaccharide, B-trisaccharide and 2'-fucosylgalactose in blood group A, B and O(H) secretors, respectively. Great individual variation was seen in the amounts of galactose-dependent oligosaccharides excreted. Injection of galactose resulted in excretion of 3-59% of the amount of oligosaccharide formed after oral administration to the same individual. The mean ratio A-trisaccharide/B-trisaccharide was 2.7 in four blood-group-A1B secretors and 0.22 in three A2B secretors and can thus serve as a parameter for chemical differentiation between the two blood groups. The excretion of larger blood-group-active oligosaccharides, including the A-pentasaccharide, the B-pentasaccharide and lactodifucotetraose, that are normal components in urine from, respectively, starved A, B, and H secretors, was about the same after oral administration of galactose or lactose. The B-trisaccharide was the only oligosaccharide detected in plasma after oral galactose administration to a blood-group-B secretor individual. The concentration was 0.38 mg/l of plasma.
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| 8. |
- Kumlien, Johan, et al.
(författare)
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Urinary excretion of a glucose-containing tetrasaccharide. A parameter for increased degradation of glycogen
- 1988
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Ingår i: Clinica Chimica Acta. - : Elsevier BV. - 0009-8981. ; 176:1, s. 39-48
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Tidskriftsartikel (refereegranskat)abstract
- The urinary excretion of a glucose-containing oligosaccharide, Glc alpha[1-6Glc alpha[1-4Glc alpha[1-4Glc, (Glc4) has been measured in various physiological and pathological conditions. The Glc4 content of 24 h samples from the same individual was relatively constant, whereas 2 h samples showed up to 4-fold variations in Glc4 concentration. This variation is associated mainly with increased excretion of Glc4 after meals. A carbohydrate-rich diet, starvation or a protein-rich diet, and intense physical activity all affected the urinary excretion of Glc4. Both oral and intravenous administration of glycogen in a Rhesus monkey resulted in increased excretion of Glc4. When Glc4 itself was injected intravenously in small amounts renal clearance was rapid and complete. In contrast, injection of a larger amount resulted in incomplete (approximately 10%) renal clearance, probably due to uptake and metabolism of the oligosaccharide. In patients with glycogen storage diseases, certain malignancies, and pancreatitis, 24 h urinary Glc4 excretion exceeded the normal range. The diagnostic implications of these observations deserve evaluation. The results presented suggest a need for standardization of nutritional status and physical activity when monitoring urinary Glc4 excretion for diagnostic purposes.
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| 9. |
- Landberg, Eva, 1966-, et al.
(författare)
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Changes in Glycosylation of Human Bile-Salt-Stimulated Lipase during Lactation
- 2000
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Ingår i: Archives of Biochemistry and Biophysics. - : Elsevier BV. - 0003-9861 .- 1096-0384. ; 377:2, s. 246-254
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Tidskriftsartikel (refereegranskat)abstract
- Bile-salt-stimulated lipase (BSSL) is an enzyme in human milk, which is important for the fat digestion in the newborn infant. BSSL is highly glycosylated and includes one site for N-glycosylation and several sites for O-glycosylation. BSSL has previously been found to express Lewis a, Lewis b, and Lewis x carbohydrate antigens. In this study, glycosylation of BSSL was studied at different times during lactation. BSSL was purified from milk collected individually from four donors at several different times during the first 6 months of lactation. The BSSL glycans were characterized through monosaccharide analysis, high-pH anion-exchange chromatography, matrix-assisted laser desorption–ionization mass spectrometry, and ELISA. Both total carbohydrate content and relative amount of sialic acid were higher in BSSL from the first lactation month as compared to BSSL from milk collected later in lactation. BSSL from the first lactation month also showed a different composition of sialylated O-linked glycans and the N-linked oligosaccharides consisted of lower amounts of fucosylated structures compared to later in lactation. We also found a gradual increase in the expression of the carbohydrate epitope Lewis x on BSSL throughout the lactation period. This study shows that glycosylation of BSSL is dependent on blood group phenotype of the donor and changes substantially during the lactation period.
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| 10. |
- Landberg, Eva, et al.
(författare)
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Glycosylation of Bile-Salt-Stimulated Lipase from Human Milk : Comparison of Native and Recombinant Forms
- 1997
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Ingår i: Archives of Biochemistry and Biophysics. - : Elsevier BV. - 0003-9861 .- 1096-0384. ; 344:1, s. 94-102
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Tidskriftsartikel (refereegranskat)abstract
- Bile-salt-stimulated lipase (BSSL) is an enzyme present in human milk. BSSL is important for fat digestion in infants. It contains one site for N-glycosylation and a serine/threonine-rich domain which is highly O-glycosylated. Both N- and O-linked sugar chains were studied on native BSSL from three donors and compared to the glycosylation of recombinant BSSL produced in Chinese hamster ovary or mouse fibroblast (C-127) cell lines. The carbohydrate composition of oligosaccharides was mapped using sugar and methylation analyses, enzyme-linked immunosorbant assay, and different separation techniques. Native BSSL was found to be highly glycosylated (19–26%). It contained a high amount of fucosylated oligosaccharides and expressed both Lewis a and Lewis b blood group antigens. None of the recombinant BSSL forms contained fucose. N-linked structures on native BSSL were identified as mainly mono- and disialylated biantennary complex type structures with or without fucose substitution. High-pH anion-exchange chromatography analysis indicated that the recombinant forms of BSSL contained similar types ofN-glycan structures differing mainly in their content of sialic acid and by the absence of fucose residues. Native BSSL contained predominantly large O-linked oligosaccharides. This was in contrast to the recombinant forms of BSSL which contained mainly short typeO-glycans with a high content of sialic acid. Interestingly, the estimated number of O-glycans attached to native BSSL was lower than that for the recombinant forms.
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