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PubMed1994

Identification and characterization of the Sda beta 1,4,N-acetylgalactosaminyltransferase from pig large intestine.

The high occurrence in large intestine epithelial cells from pig of a beta-N-acetylgalactosaminyltransferase with a substrate specificity very similar to that of the Sda beta 1,4-N-acetylgalactosaminyltransferase from other tissues is reported. The enzyme strictly recognized the NeuAc alpha 2,3Gal beta terminal sequence of N- and O-linked oligosaccharides bound to glycoproteins. The transferase activity required Mn2+ and an optimum pH of 7.4. In contrast to the kidney Sda-enzyme from humans and other mammals, the microsomal fraction of pig colonic cells expressed a very high activity even in the absence of Triton X-100. A rapid procedure is presented for the large scale preparation of GalNAc beta 1,4(NeuAc alpha 2,3)Gal beta 1,4Glc from NeuAc alpha 2,3Gal beta 1,4Glc. The biosynthesized tetrasaccharide was completely resistant to the action of neuraminidase from Vibrio cholerae, whereas about 60% of N-acetylneuramic acid was cleaved by neuraminidase from Newcastle disease virus. HPLC separation of different compounds is reported.

Animals↗
PubMed2005

Suitability of genomic DNA synthesized by strand displacement amplification (SDA) for AFLP analysis: genotyping single spores of arbuscular mycorrhizal (AM) fungi.

Limited biological samples of microbial origin often yield insufficient amounts of genomic DNA, making application of standard techniques of genetic analysis, like amplified fragment length polymorphism (AFLP), virtually impossible. The Phi29 DNA polymerase based whole genome amplification (WGA) method has the potential to alleviate this technical bottleneck. In the present work, we have sought to investigate the suitability of genomic DNA synthesized using Phi29 based WGA for AFLP analysis. We first used genomic DNA from Saccharomyces cerevisiae to optimize the protocol for the use of SDA-amplified DNA for AFLP analysis. Based on the optimized protocol we obtained AFLP fingerprints which were indistinguishable from the non-amplified genomic DNA. Finally, AFLP analysis was performed using SDA synthesized genomic DNA from single spores of various species of arbuscular mycorrhizal (AM) fungi. Unique and highly reproducible fingerprints for each species were obtained. The present study introduces the application of WGA-mediated AFLP to AM fungal biology; similarly, our protocol could be useful for other microbial genomes currently not amenable to genetic analysis owing to the paucity of starting template.

DNA Replication↗
PubMed1983

A blood group Sda-active pentasaccharide isolated from Tamm-Horsfall urinary glycoprotein.

Human Tamm-Horsfall urinary glycoprotein from an individual of the blood group Sd(a+) phenotype was tritium-labelled by treatment with galactose oxidase and sodium boro[3H]hydride and was then digested with endo-beta-galactosidase. A series of dialysable, labelled fragments was released from which a pentasaccharide was isolated that strongly inhibited the agglutination of Sd(a+) red cells by human anti-Sda serum and hence contained the Sda determinant structure. Reduction, methylation analysis and sequential exo-glycosidase digestion established the structure of the pentasaccharide as: GalNAc beta(1 leads to 4)[NeuAc(2 leads to 3)]Gal beta(1 leads to 4)GlcNAc beta(1 leads to 3)Gal

Blood Group Antigens↗
PubMed1997

Synthesis of the Sda determinant and two analogous tetrasaccharides.

To contribute to the possibility of studying in greater detail the biological significance of Sda-containing glycans as occur in Tamm-Horsfall glycoprotein, the following three spacer-linked tetrasaccharides have been synthesized: the Sda determinant alpha-Neu p5Ac-(2-->3)-[beta- D-GalpNAc-(1-->4)]-beta-D-Galp-(1-->4)-beta-D-GlcpNAc-(1-->O)(CH2)5NH 2 (1), the Gal-analogue alpha-Neup5Ac-(2-->3)-[beta-D-Galp-(1-->4)]-beta-D-Galp-(1-->4) -beta-D-GlcpNAc-(1-->O)(CH2)5NH2 (2), and the GlcNAc-analogue alpha-Neup5Ac-(2-->3)-[beta-D-GlcpNAc-(1-->4)]- beta-D-Galp-(1-->4)-beta-D-GlcpNAc-(1-->O)(CH2)5NH2 (3). The general trisaccharide acceptor 5-azidopentyl (methyl 5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy- D-glycero-alpha-D-galactonon-2-ulopyranosylonate)-(2-->3)-(2 ,6-di-O-benzyl- beta-D-galactopyranosyl)-(1-->4)-3,6-di-O- benzyl-2-deoxy-2-phthalimido-beta-D-glucopyranoside was prepared, using methyl (phenyl 5- acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-2-thio-D-glycero-D-galacto- non- 2-ulopyranosid)- onate as the sialyl donor. For the syntheses of 1, 2, and 3 the glycosyl donors 3,4,6-tri-O- acetyl-2-deoxy-2-phthalimido-alpha-D-galactopyranosyl bromide, 2,3,4,6-tetra-O-acetyl-alpha-D- galactopyranosyl bromide, and 3,4,6-tri-O-acetyl-2-deoxy-2-phthalimido -beta-D-glucopyranosyl trichloroacetimidate, respectively, proved to be the most suitable.

Carbohydrate Conformation↗
PubMed1990

Postnatal development of rat colon epithelial cells is associated with changes in the expression of the beta 1,4-N-acetylgalactosaminyltransferase involved in the synthesis of Sda antigen of alpha 2,6-sialyltransferase activity towards N-acetyl-lactosamine.

beta 1,4-N-Acetylgalactosaminyltransferase (beta 1,4GalNAc-transferase) and alpha 2,3-sialyltransferase are both involved in the biosynthesis of the Sda blood group antigen, which is also present in cells of large intestine. The expression of these enzymes and of alpha 2,6-sialyltransferase activity towards N-acetyl-lactosamine was investigated in rat intestinal cells and correlated with both cell differentiation and extent of postnatal maturation. The beta 1,4GalNAc-transferase activity was exclusively found in epithelial cells of the large intestine, preferentially in the proximal segments suggesting a proximal-distal gradient of expression. The beta 1,4GalNAc-transferase and alpha 2,3-sialyltransferase activity towards N-acetyl-lactosamine were expressed in all cell fractions of the colonic crypt, with a maximum activity in the deeply located cells; therefore Sda antigen biosynthesis appears to occur preferentially at a specific stage of cell differentiation. By using N-acetyl-lactosamine as an acceptor, the predominant sialyltransferase in the colon cells was that capable of adding sialic acid in the alpha 2,3- linkage, whereas in the ileum cells the major enzyme was that forming the alpha 2,6-isomer. There were dramatic changes in the expression of colonic beta 1,4GalNac-transferase and of alpha 2,6-sialyltransferase activity towards N-acetyl-lactosamine during postnatal maturation. The former enzyme, practically absent at birth, increased slowly in the first days of life and then rapidly after weaning; by contrast, the latter enzyme was largely expressed only in newborn animals. As the colonic alpha 2,3-sialyltransferase activity towards N-acetyl-lactosamine did not change during the postnatal period, the ratio between the alpha 2,6- and alpha 2,3-sialyltransferase activities was reversed after weaning.

Amino Sugars↗
PubMed2004

Prospective evaluation of BDProbeTec strand displacement amplification (SDA) system for diagnosis of tuberculosis in non-respiratory and respiratory samples.

Nucleic acid amplification techniques (NAATs) have been demonstrated to make significant improvements in the diagnosis of tuberculosis (TB), particularly in the time to diagnosis and the diagnosis of smear-negative TB. The BD ProbeTec strand displacement amplification (SDA) system for the diagnosis of pulmonary and non-pulmonary tuberculosis was evaluated. A total of 689 samples were analysed from patients with clinically suspected TB. Compared with culture, the sensitivity and specificity for pulmonary samples were 98 and 89 %, and against final clinical diagnosis 93 and 92 %, respectively. This assay has undergone limited evaluation for non-respiratory samples and so 331 non-respiratory samples were tested, identifying those specimens that were likely to yield a useful result. These were CSF (n = 104), fine needle aspirates (n = 64) and pus (n = 41). Pleural fluid (n = 47) was identified as a poor specimen. A concern in using the SDA assay was that low-positive samples were difficult to interpret; 7.8 % of specimens fell into this category. Indeed, 64 % of the discrepant results, when compared to final clinical diagnosis, could be assigned as low-positive samples. Specimen type did not predict likelihood of a sample being in the low-positive zone. Although the manufacturers do not describe the concept of a low-positive zone, we have found that it aids clinical diagnosis.

Ascitic Fluid↗
PubMed1991

Comparison between the erythrocyte and urinary Sda antigen distribution in a large number of individuals from Emilia-Romagna, a region of northern Italy.

In this study we found that the frequencies of Sda antigen on erythrocytes and urine of a large number of individuals from Emilia-Romagna (a region of northern Italy) are 0.89 and 0.93, respectively. The hypothesis that the infection by pyelonephritogenic Escherichia coli strains with specific adhesins for the alpha 2,3sialyl-galactosyl structure might operate as selective agents for the high frequency of Sda antigen in distal renal cells is discussed.

Blood Group Antigens↗
PubMed1976

Cad(super Sda) in a British family with eastern connections: a note on the specificity of the Dolichos biflorus lectin.

Cad, Sd(a++) or Super Sda is a rare, inherited, dominant blood group character which is of much interest, not only with regard to problems in pretransfusion tests (erythrocyte polyagglutination) but also in the field of lectin specificity. We have studied this blood group character in a British family with Eastern connections and present a brief account of its serological and clinical importance. Most persons are Sd(a+) but there is a wide distribution of antigen strength, ranging from ordinary Sd(a+) to Cad. Most persons also have weak anti-Sda in their serum; this is ordinarily of no clinical importance, but could cause problems if Cad bloods are transfused. The chief structural determinant of Cad specificity is N-acetyl-D-galactosamine in alpha-linked position, yet it is clearly distinguishable by use of appropriate lectins from other blood group antigens, A and Tn, which also have this acetyl-hexosamine as their chief structural determinant. A method for the rapid identification of Cad, applicable to all ABO groups, is described. The lectin of Dolichos biflorus, which is specific for N-acetyl-D-galactosamine in alpha-linked position, reacts strongly with A(A1), Tn and Cad cells, its action on Cad cells being much the strongest. Absorption-elution studies show that one and the same lectin reacts with both A1 and Tn cells. Absorption with Cad cells abolishes activity for A1, Tn and Cad cells; whereas absorption with A1 or Tn cells leaves activity for Cad. This does not necessarily indicate that anti-Cad is a separate component since the same result can be obtained by simply diluting the Dolichos reagent. However, eluates from Cad cells react only with Cad cells, whereas eluates from A1 or Tn cells react with A1, Tn and Cad cells.

ABO Blood-Group System↗
PubMed2002

Evaluation of a strand displacement amplification assay (BD ProbeTec-SDA) for detection of Neisseria gonorrhoeae in urine specimens.

The performance of a strand displacement amplification assay (the BDProbeTec-SDA assay) in detecting Neisseria gonorrhoeae in urine specimens was evaluated. When performed under stringent quality control conditions, the BDProbeTec-SDA assay is a sensitive, specific, and efficient method for the screening of large numbers of noninvasively obtained specimens. Because the predictive value of an assay is a function of the prevalence of the disease, culture confirmation is needed for samples with positive results from populations in which the prevalence of a disease is low or in situations in which false-positive results may have important medical, psychosocial, or medicolegal consequences.

Culture Media↗
PubMed1991

Detection of serum antibodies using LBC cell-grown sialodacryoadenitis (SDA) virus.

The TG strain of sialodacryoadenitis (SDA) virus propagated in LBC cell culture (TGr/LBC) reacted strongly with anti-TGr rat serum in complement fixation (CF) tests, showing much higher titers with anti-TGr rat serum than mouse hepatitis virus MHV-NuU antigen. The antigenicity was not affected after ether treatment while infectivity was lost. The TGr/LBC antigen might be useful in seromonitoring for SDA infection in rats.

Animals↗
PubMed1989

Enzymic synthesis, chemical characterisation and Sda activity of GalNAc beta 1-4[NeuAc alpha 2-3]Gal beta 1-4GlcNAc and GalNAc beta 1-4[NeuAc alpha 2-3]Gal beta 1-4Glc.

The tetrasaccharides GalNAc beta 1-4[NeuAc alpha 2-3]Gal beta 1-4Glc and GalNAc beta 1-4[NeuAc alpha 2-3]Gal beta 1-4GlcNAc were synthesised by enzymic transfer of GalNAc from UDP-GalNAc to 3'-sialyllactose (NeuAc alpha 2-3 Gal beta 1-4Glc) and 3'-sialyl-N-acetyllactosamine (NeuAc alpha 2-3Gal beta 1-4GlcNAc). The structures of the products were established by methylation and 1H-500 MHz NMR spectroscopy. In Sda serological tests the product formed with 3'-sialyl-N-acetyllactosamine was highly active whereas that formed with 3'-sialyllactose had only weak activity.

Animals↗
PubMed1991

UDP-GalNAc:NeuAc alpha 2,3Gal beta-R (GalNAc to Gal) beta 1,4-N-acetylgalactosaminyltransferase responsible for the Sda specificity in human colon carcinoma CaCo-2 cell line.

The UDP-GalNAc:NeuAc alpha 2,3Gal beta-R (GalNAc to Gal) beta-1,4-N-acetylgalactosaminyltransferase (beta 1,4GalNAc-transferase) is the enzyme responsible for the addition of the immunodominant sugar of the Sda isto-blood group determinant. In humans the enzyme is mainly expressed in the large intestine. We screened nine human colorectal carcinoma cell lines (SW-948, SW-948 FL, SW-480, SW-48, SW-1417, COLO-205, LOVO, HT-29 and CaCo-2) in order to ascertain the occurrence of beta 1,4GalNAc-transferase. Only in CaCo-2 cells the glycosyltransferase was detected and the activity increased with the degree of enterocytic differentiation. Nevertheless, in highly differentiated CaCo-2 cells the activity was thirty times lower than that found in cells detached from normal colon mucosa. These results support the notion that the expression of beta 1,4GalNAc-transferase is a marker of the colonic cell maturation.

Blood Group Antigens↗
PubMed1986

Characterization of N-acetyl-beta-D-galactosaminyltransferase from guinea-pig kidney involved in the biosynthesis of Sda antigen associated with Tamm-Horsfall glycoprotein.

This study reports the catalytic activity of N-acetyl-beta-D-galactosaminyltransferase from guinea-pig kidney towards such non-glycoprotein acceptors as small oligosaccharides and glycolipids, having a carbohydrate structure similar to that of the Sda antigen associated with human Tamm-Horsfall glycoprotein. 3'-O-Sialyllactose, but not 6'-O-sialyllactose or lactose, was an effective acceptor of the glycosyltransferase. On the basis of enzymic and chemical treatment of the tetrasaccharide obtained by the transfer of [14C]GalNAc to 3'-O-sialyllactose, we propose that the glycosyltransferase attaches beta-D-GalNAc to O-4 of the galactose residue that is substituted at O-3 by sialic acid. The GM3 ganglioside, in which the identical carbohydrate moiety of 3'-O-sialyllactose is bound to a ceramide residue, did not serve as an acceptor of the kidney-N-acetyl-beta-D-galactosaminyltransferase and did not behave as a competitive inhibitor of the Tamm-Horsfall glycoprotein in the transferase assay. These results indicate that the hydrophobic moiety in the ganglioside hinders the action of N-acetylgalactosaminyltransferase. Study of the transferase activity towards a heterogeneous glycopeptide species prepared from a Sd(a-) Tamm-Horsfall glycoprotein indicated that guinea-pig kidney enzyme preferentially transferred [14C]GalNAc to the oligosaccharides having a tetraantennary branching-structure.

Animals↗
PubMed1997

Synthesis of two analogues of the Sda determinant. Replacement of the sialic acid residue by a sulfate or a carboxymethyl group.

Two analogues of the Sda determinant tetrasaccharide have been synthesized in order to investigate the physiological role of this carbohydrate moiety. These saccharides, having two different anionic substitutes for the sialic acid residue, are: beta-D-GalpNAc-(1-->4)-3-O-SO3 H- beta-D-Galp-(1-->4)-beta-D-GlcpNAc-(1-->O)(CH2)5NH2 and beta-D-GalpNAc-(1-->4)-3-O- COOH-beta-D-Galp-(1-->4)-beta-D-GlcpNAc-(1-->O)(CH2)5NH2. 5-Azidopentyl (2,6-di-O- benzyl-beta-D-galactopyranosyl)-(1-->4)-3,6-di-O-benzyl-2-deoxy-2- phthalimido-beta-D-glucopyranoside served as a general building block. The trisaccharides were obtained after prior selective derivatization of HO-3' of the disaccharide derivative via a dibutyltin oxide mediated reaction, followed by coupling at HO-4' with 3,4,6-tri-O-acetyl-2-deoxy-2-phthalimido-beta-D-galactopyranosyl trichloroacetimidate, and processing of the formed trisaccharide derivatives into their free forms.

Carbohydrate Conformation↗
PubMed1998

Anxiolytic-like effects of perospirone, a novel serotonin-2 and dopamine-2 antagonist (SDA)-type antipsychotic agent.

We examined the anxiolytic potential of perospirone, a novel serotonin-2 and dopamine-2 antagonist (SDA)-type antipsychotic agent, and compared its effects with those of the standard anxiolytic diazepam and the conventional antipsychotic haloperidol by using conditioned defensive burying (CDB) and social interaction (SI) tests in rats. The tests were conducted 1 h after oral administration of the drug. Diazepam inhibited CDB specifically directed toward a probe previously associated with brief electric shock and increased the time spent in SI by pairs of naive rats in a brightly illuminated novel environment. Perospirone mimicked the effects of diazepam by dose dependently suppressing CDB and facilitating SI. In contrast, haloperidol failed to inhibit CDB or increase SI. These results suggested that, unlike the conventional antipsychotic haloperidol, perospirone exerts anxiolytic-like effects in animal models with different motivational and emotional states. A braoder efficacy of perospirone for the treatment of anxiety and related symptoms in schizophrenia is discussed.

Aggression↗
PubMed1980

Increase of blood group A and loss of blood group Sda activity in the mucus from human neoplastic colon.

Aqueous extracts of human neoplastic and adjacent normal colonic mucosa were investigated for hemagglutination inhibition of both the anti-A serum and the Dolichos biflorus lectin. The anti-A antiserum was inhibited by the extracts from neoplastic tissues to a much higher extent than by that from normal mucosa; the inhibition was strictly dependent on the blood group and the secretor status of the individual. The inhibition titers against the Dolichos lectin were much lower for the tumor than for the normal tissue and the inhibition of this lectin was not dependent on blood group and secretor status. In addition, studies on the specificity of both agglutinins showed that only the anti-A antiserum reacted with the blood group A antigen in the colonic mucus whereas the Dolichos lectin reacted with a different substance which was not related to the blood group ABO system. The Dolichos reactive mucin was isolated by gel chromatography and by affinity chromatography on Dolichos-Sepharose. The partially purified mucin did not show any blood group A or H activity but reacted with all GalNAc specific lectins tested. A very high specific activity was obtained against the Dolichos biflorus lectin whereas the agglutinins from Salvia sclarea, Glycine max. (soybean) and Helix pomatia were less strongly inhibited no matter whether blood group A1, Tn, or Cad erythrocytes were used. By far the highest inhibitory activity was found against the human anti-Sd(a) antiserum regardless of whether the red blood cells were Cad or Sd(a+). By gel chromatography an equally pure mucin fraction could be obtained from neoplastic tissues which did not bind to either the anti-A antiserum nor the GalNAc specific lectins but could inhibit the anti-Sda antiserum at a far lower specific activity than the normal preparation.

ABO Blood-Group System↗
PubMedDate not supplied

Anti-Sdx: a "new" auto-agglutinin related to the Sda blood group.

Two examples of a "new" IgM saline-agglutinating auto-antibody are described. The antibodies bind complement, have the ability to cause in vivo hemolysis, and are most active at room temperature at a pH of about 6.5. Despite tests on more than 5,000 people, no nonreactive cell sample has been found. The reactive antigen is not denatured by neuraminidase, papain, or ficin, and is present on i adult red blood cells. The antibodies appear to be slightly inhibited by human saliva and milk, and more convincingly inhibited by urine from Sd(a+) persons. They are not inhibited by urine from Sd(a-) persons, but are strongly inhibited by guinea pig urine. The serologic characteristics indicate a relationship to the Sda blood group and the auto-antibody has been named antiSdx. Sdx antigen is present on red blood cells from some higher primates and is absent from rabbit, rhesus monkey, dog and sheep cells.

ABO Blood-Group System↗
PubMed1989

Expression of UDP-GalNAc:NeuAc alpha 2,3Gal beta-R beta 1,4(GalNAc to Gal) N-acetylgalactosaminyltransferase involved in the synthesis of Sda antigen in human large intestine and colorectal carcinomas.

N-Acetylgalactosamine beta 1,4-linked to a galactose residue substituted in O-3 with one N-acetylneuraminic acid residue is the immunodominant sugar of the human blood group Sda antigen which is also largely present in the kidney medulla and colon mucosa. A beta 1,4-N-acetylgalactosaminyltransferase very similar to that previously described in urine of Sd(a+) individuals (F. Serafini-Cessi, N. Malagolini, and F. Dall'Olio. Arch. Biochem. Biophys., 266: 573-582, 1988) has been identified in cells released from human large intestine. The higher values of beta 1,4-N-acetylgalactosaminyltransferase activity were detected in proximal and medial segments of the large intestine, suggesting a proximal-distal gradient of the enzyme expression. When the beta 1,4-N-acetylgalactosaminyltranferase activity of colorectal carcinoma specimens from 18 patients was compared with that of the normal mucosa surrounding the tumor, a constant and in several cases drastic reduction of the activity was detected in tumor cells. Three human colorectal adenocarcinoma cell lines (Colo-205, SW-48, and SW-948) have been found to lack the beta 1,4-N-acetylgalactosaminyltransferase activity. Altogether, these results support the notion that the malignant transformation drastically affects the expression of this glycosyltransferase in large bowel cells.

Antigens, Tumor-Associated, Carbohydrate↗