Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: DrugBank:EXPT00572 (Asn)
 11,732 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

One neutral and two acidic glycoasparagines were isolated from the urine of patients with aspartylglycosylaminuria (AGU). The neutral one was identified as beta-Gal-(1 leads to 4)-beta-GlcNAc-Asn. The acidic ones were composed of 1 mole of sialic acid and 2 moles each of galactose and N-acetylglucosamine, attached to asparagine, and were isomeric with respect to the position of sialic acid attachment since they produced the same glycoasparagine on incubation with the neuraminidase [EC 3.2.1.18] from Clostridium perfringens. The structure of the resulting sialic acid-free glycoasparagine was determined to be beta-Gal-beta-GlcNAc-beta-Gal-(1 leads to 4)-beta-GlcNAc-Asn based mainly on the results of sequential enzymatic degradations.
 ...
PMID:Characterization of one neutral and two acidic glycoasparagines isolated from the urine of patients with aspartylglycosylaminuria (AGU). 18 76

Bovine prothrombin contains three asparagine-linked sugar chains in 1 molecule. The sugar chains were quantitatively released from the polypeptide backbone by hydrazinolysis. All of the oligosaccharides thus obtained contain N-acetylneuraminic acid. Sialidase treatment of these acidic oligosaccharides released three isomeric oligosaccharides, N-1, N-2 and N-3. N-3 was a typical complex type asparagine-linked sugar chain widely found in other glycoprotein, while N-1 and N-2 were unique, because they contain Gal beta 1 leads to 3GlcNAc grouping in the outer chain moiety. By comparing the data of methylation analysis of the acidic oligosaccharides before and after sialidase treatment, the structures of the sugar chains of bovine prothrombin were confirmed as a mixture of NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6(NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 3)Man beta 1 leads to 4GlcNAc beta 1 leads to 4GlcNAc leads to Asn, NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6[NeuAc alpha 2 leads to 3Gal beta 1 leads to 3(NeuAc alpha 2 leads to 6)GlcNAc beta 1 leads to 2Man alpha 1 leads to 3]Man beta 1 leads to 4GlcNAc beta 1 leads to 4GlcNAc leads to Asn, NeuAc alpha 2 leads to 3Gal beta 1 leads to 3(NeuAc alpha 2 leads to 6)GlcNAc beta 1 leads to 2Man alpha 1 leads to 6[NeuAc alpha 2 leads to 3Gal beta 1 leads to 3(NeuAc alpha 2 leads to 6)GlcNAc beta 1 leads to 2Man alpha 1 leads to 3]Man beta 1 leads to 4GlcNAc beta 1 leads to 4GlcNAc leads to Asn and their partially desialized forms.
 ...
PMID:The carbohydrate of bovine prothrombin. Occurrence of Gal beta 1 leads to 3GlcNAc grouping in asparagine-linked sugar chains. 44 25

Two major glycoasparagines (2-acetamido-N-(4'-L-aspartyl)-2-deoxy-beta-D-glycosylamines) were isolated from the urine of patients with aspartylglycosylaminuria (AGU). They were composed of equimolar amounts of sialic acid, galactose, glucosamine, and aspartic acid. They were isomeric with respect to the position of sialic acid attachment, since they produced the same glycoasparagine on incubation with the neuraminidase from Clostridium perfringens. The structure of the resulting sialic acid-free glycoasparagine was determined as beta-Gal-(1 leads to 4)-beta-GlcNAc-Asn based on the following findings. It produced galactose on incubation with beta-galactosidase, and N-acetyllactosamine and aspartic acid on incubation with 4-L-aspartylglycosylamine amindo hydrolase.
 ...
PMID:Characterization of two glycoasparagines isolated from the urine of patients with aspartylglycosylaminuria (AGU). 121 85

Affinity labeling using [125I-Tyr36]PYY and homobifunctional affinity crosslinking reagents of the rabbit Y2 receptor for peptide YY(PYY) results in specifically labeled proteins of both M(r) = 50,000 to 60,000 and M(r) = 96,000 to 115,000 [1,2]. In this work the glycoprotein nature of affinity labeled Y2 receptor proteins were investigated by enzymatic deglycosylation using neuraminidase, endoglycosidase F (endo F), N-glycosidase F (PNGase F), and O-glycanase treatment. Only N-glycosidase F and neuraminidase increased the electrophoretic mobility of the radiolabeled receptor bands, whereas all other glycosidases did not. PNGase F treatment of both radiolabeled receptor bands electroeluted from gel slices reduced the apparent molecular mass of by 16-17 kDa units, that is M(r) = 96,000 to 79,000 and M(r) = 60,000 to 44,000, indicating removal of N-linked oligosaccharide chains of similar size from both species. Neuraminidase treatment caused slight increases in the electrophoretic mobilities suggesting the presence of terminal sialic residues. It is concluded that the Y2 binding proteins are N-linked complex (sialo)glycoproteins with a minimal core protein size of M(r) = 44,000. Furthermore, based on this sensitivity pattern of the glycosidases, the Asn-linked carbohydrate may be of the tri- or tetra-antennary complex type containing terminal sialic acid residues.
 ...
PMID:Y2 receptor proteins for peptide YY and neuropeptide Y. Characterization as N-linked complex glycoproteins. 132 32

A glycoprotein, M(r) 200,000, which has the biological activity of the neurotoxin-responsive Na+ channel, was isolated from a clonal line of mouse neuroblastoma cells, N-18. The glycoprotein was purified to homogeneity in 18% yield by methods used to purify glycoproteins, which included metabolic labeling of the cells with L-[3H]fucose and binding of the radioactive glycoproteins to WGA- and lentil-Sepharose, and DEAE-cellulose. The glycoprotein has biological activity of neurotoxin-responsive ion flux when reconstituted into artificial phospholipid vesicles. This activity was shown to depend on the presence of sialic acid since treatment of the purified, reconstituted glycoprotein with Vibrio cholerae neuraminidase abolished the response to neurotoxins of 86Rb flux. The [3H]fucose-containing glycopeptides derived by Pronase digestion of the glycoprotein were characterized by affinity to immobilized lectins and contained di-, tri-, and tetra-antennary oligosaccharides in a ratio of 2:4:3. Most of the glycopeptides were sialylated as shown by binding characteristics to immobilized serotonin-Sepharose with and without neuraminidase. The structure of the diantennary oligosaccharides was elucidated by 500-MHz 1H NMR spectroscopy. The Con A-bound fraction contains alpha-NeuNAc-(2-->6)-bound group on the GlcNAc5' antenna and an alpha-NeuNAc-(2-->3)-bound groups on the GlcNAc5 antenna. An alpha-L-fucosyl group is (1-->6)-bound to the Asn core GlcNAc1 residue.
 ...
PMID:Oligosaccharide composition of the neurotoxin-responsive sodium channel of mouse neuroblastoma and requirement of sialic acid for biological activity. 133 66

Tn polyagglutinability syndrome is an acquired condition where erythrocytes express Tn neo-antigen and become susceptible to hemagglutination by the naturally occurring anti-Tn present in normal sera. Early studies had indicated that O-linked N-acetyl galactosamine was the sole serologic Tn determinant, but more recently O-linked NeuNAc alpha 2, 6GalNAc also has been implicated as a Tn antigen (sialosyl-Tn). However, none of these studies were performed on purified glycoproteins. In this report we examine oligosaccharides of glycophorins A and B purified from Tn erythrocytes of two affected individuals to establish how N- and O-linked saccharides differ from normal. Analysis of carbohydrate composition and treatment with N-glycanase showed that the Asn-linked unit of glycophorin A was not affected. O-linked oligosaccharides were obtained by beta-elimination in the presence of tritiated sodium borohydride. The reduced radiolabeled products were fractionated by Bio-Gel P-2 chromatography, and their structures were investigated by comparison with standards, by monosaccharide quantification, and by neuraminidases of known specificities. The results show that Tn glycophorins from both donors contain intact and truncated forms of trisaccharide and tetrasaccharide NeuNAc alpha 2,3Gal beta 1,3GalNAc and NeuNAc alpha 2,3Gal beta 1,3- (NeuNAc alpha 2,6)GalNAc usually present in glycophorins A and B. The truncated forms include the protein O-linked monosaccharide, GalNAc and disaccharide, NeuNAc alpha 2,6GalNAc (major isomer). The presence of intact glycans in the total population of Tn erythrocytes was confirmed by their susceptibility to T activation after treatment with neuraminidase. The proportion of the four species was not identical in glycophorins of these two donors but, in both, the truncated units predominated and the amount of the disaccharide was approximately one half of that of the monosaccharide. The data are consistent with alterations in UDPGal:GalNAc beta 1,3galactosyl transferase that may have multiple molecular origins and with induction of a specific GalNAc protein alpha 2,6 sialosyl transferase in Tn hematopoietic precursor cells. The molecular basis for these alterations awaits further study.
 ...
PMID:O-linked oligosaccharides of glycophorins A and B in erythrocytes of two individuals with the Tn polyagglutinability syndrome. 142 10

Two major glycoproteins (PAS-6 and PAS-7) from bovine milk fat globule membrane were selectively extracted with urea and KCl, co-purified by repeated gel filtration on Sephacryl S-200 and then separated by affinity chromatography on concanavalin A-agarose column. The two purified glycoproteins showed a single band by SDS-PAGE, and their molecular masses were estimated to be 50 kDa for PAS-6 and 47 kDa for PAS-7. Both PAS-6 and PAS-7 were resolved several variants by analytical isoelectric focusing. These were shifted to a single band at pI 6.2 for PAS-6 and at pI 6.5 for PAS-7 by neuraminidase. PAS-6 contained 7.1% and PAS-7 5.5% of carbohydrate; the molar ratio of fucose:mannose:galactose:N-acetyl galactosamine:N-acetyl glucosamine:sialic acid was 1.0:3.0:2.0:6.1:5.0:1.3 for PAS-6 and 1.0:3.1:2.2:0:4.1:1.1 for PAS-7. Mild alkaline treatment and affinity to various lectins indicated that PAS-6 had O- and N-linked oligosaccharide chains, while PAS-7 had only the N-linked type. The major amino acid residues of PAS-6 were Glu, Ser and Gly, and those of PAS-7 were Asp, Glu, Gly and Leu. The N-terminal amino acids of both glycoproteins were blocked. PAS-6 and PAS-7 digested with trypsin had a different peptide map, two major peptides having the same retention time on HPLC and being common to PAS-6 and PAS-7 having the same amino acid sequences of H-Gln-Ser-Gly-Asn-Lys-Asn-Pro-Ser-Glu-Ile-Ser-OH and H-Ile-Phe-Pro-Gly-Asn-Met-Asp-Asn-Ser-His-Lys-OH.
 ...
PMID:Purification and characterization of major glycoproteins, PAS-6 and PAS-7, from bovine milk fat globule membrane. 164 94

The glycoprotein hormones, equine chorionic gonadotropin (eCG) and lutenizing hormone (eLH), possess a beta-subunit with an identical amino acid sequence. The Asn-linked oligosaccharide chains of eCG beta and eLH beta were quantitatively liberated as tritium-labeled oligosaccharides by hydrazinolysis followed by N-acetylation and NaB3H4-reduction. Paper electrophoresis in combination with sialidase digestion and solvolytic desulfation indicated that eCG beta contained neutral and sialylated oligosaccharides, while eLH beta contained neutral, sialylated, sulfated, and both sialylated and sulfated oligosaccharides. In addition, elution profiles on a Bio-Gel P-4 column of the neutralized oligosaccharide mixtures of eCG beta and eLH beta were different, indicating that the molecular masses of oligosaccharides of the two glycoproteins are different. Therefore, this suggests that the structures of the Asn-linked oligosaccharide chains of eCG beta and eLH beta are different although they have an identical amino acid sequence.
 ...
PMID:Beta-subunits of equine chorionic gonadotropin and lutenizing hormone with an identical amino acid sequence have different asparagine-linked oligosaccharide chains. 170 32

Following incubation of UMR-106 cells for 48 h in the presence of [3H]glucosamine and [35S]sulfate, the newly synthesized anionic glycoconjugates were isolated from the culture medium by cetylpyridinium chloride/ethanol precipitation and further separated by DEAE-Sephacel chromatography into two radiolabelled fractions, a major component, UM I, and a minor component, UM II. UM I appeared to be homogeneous as shown by Sepharose CL-4B chromatography under dissociative conditions, and SDS-polyacrylamide gel electrophoresis. It showed a molecular mass of approximately 93 kDa on 4-15% gels. UM I was partially degraded by brief treatment with trypsin, releasing a small, terminal peptide that contained 47.6% of 35S but no 3H. Treatment of UM I with neuraminidase and 0.1 N H2SO4 (1 h at 80 degrees C), respectively, released 27% 3H and 38.4% 3H plus 41% 35S, suggesting the presence of a significant number of sialic acid residues, as shown by Sephadex G-50 chromatography of the digests. Amino acid analysis showed that the UM I glycoconjugate was rich in acidic amino acids (12.6% aspartic acid and 21.2% glutamic acid residues) and its N-terminal sequence was Phe-Ser-Met-Lys-Asn-Phe-, which is identical to the published N-terminal amino acid sequence of rat bone sialoprotein II. Keratanase treatment of UM I released 26% of the incorporated radioactivity, suggesting the presence of keratan sulfate chains. UM II contained a chondroitinase ABC-sensitive proteoglycan.
 ...
PMID:Further purification and characterization of newly synthesized anionic glycoconjugates secreted by cultured UMR-106 cells: evidence that the major anionic glycoconjugate secreted by these cells is similar to bone sialoprotein II. 176 Jan 56

Albumin Casebrook is an electrophoretically slow genetic variant of human albumin with a relative molecular mass 2.5 kDa higher than normal albumin. It constitutes about 35% of total serum albumin in heterozygous carriers. The decrease in negative charge observed on incubation with sialidase suggested the presence of a carbohydrate moiety and the normalization of molecular weight following treatment with Endo-F indicated that this was an N-linked oligosaccharide. Partial acid hydrolysis and limited tryptic digestion established that the oligosaccharide was located in the C-terminal domain, between residues 367 and 585. Tryptic, chymotryptic and S. aureus V8 proteinase digestions were carried out and the resulting glycopeptides were purified on concanavalin A-Sepharose. Peptide mapping of bound and unbound fractions followed by amino acid composition and sequence analysis, established a point mutation of 494 Asp----Asn. This introduces an Asn-Glu-Thr N-linked oligosaccharide attachment sequence centered on Asn-494 and explains the increase in molecular mass. There was no apparent pathology associated with the presence of this new glycosylated albumin, which was detected in two unrelated individuals of Anglo-Saxon descent.
 ...
PMID:Structural characterization of a glycoprotein variant of human serum albumin: albumin Casebrook (494 Asp----Asn). 185 51


1 2 3 4 5 6 7 8 Next >>