Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The enzymatic transfer of the sugar portion from UDP-N-acetylgalactosamine to pyridylamino (PA) lacto-N-fucopentaose I (Fuc alpha 1-2Gal beta 1-3GlcNAc beta 1-4Glc-PA) was detected by high-performance liquid chromatography. Separation of the fluorescent product from the fluorescence-labeled acceptor was achieved within 10 min by reversed-phase high-performance liquid chromatography. Rat stomach enzyme activity was detected in the microsomal fraction from antrum but not corpus. Ohara et al. (1986, Comp. Biochem. Physiol. 83B, 273-275) reported that the N-acetylgalactosamine content in antrum mucin was greater than that in corpus mucin and antrum mucin had strong blood group A activity. The prominent asymmetrical distribution of the enzyme detected here well supports these findings. The elution position of the fluorescent product was the same as that of the product formed by the action of type A human serum toward the acceptor. Its hydrolysis by alpha-N-acetylgalactosaminidase yielded the acceptor. It is thus evident that the detected enzyme is the same as that producing the blood group A structure.
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PMID:Detection of UDP-N-acetylgalactosamine-oligosaccharide N-acetylgalactosaminyltransferase activity in rat stomach and human serum by high-performance liquid chromatography. 314 99

In the final stages of the terminal glycosylation of N-linked complex oligosaccharides, UDP-galactose: N-acetylglucosamine beta-1,4-galactosyltransferase (galactosyltransferase) transfers galactose (Gal) onto the N-acetylglucosamine (GlcNAc) residue of each branch of a biantennary oligosaccharide. Purified rat liver Golgi galactosyltransferase was used with GlcNAc beta 1,2-Man alpha 1,6-(GlcNAc beta 1,2-Man alpha 1,3-)-Man beta 1,4-GlcNAc beta 1,4-(Fuc alpha 1,6-)-GlcNAc-Asn in order to determine the sequence of addition of Gal residues to the biantennary oligosaccharide. The different galactosylated products were separated by concanavalin A affinity chromatography and high voltage paper electrophoresis in borate. It was found that Gal was transferred at a much faster rate to the GlcNAc beta 1,2-Man alpha 1,3-branch than to the GlcNAc beta 1,2-Man alpha 1,6-branch, i.e. k1 was at least 5 times larger than k2. Also, k3 was larger than k4, indicating that most of the digalactosylated product "GG" was formed by the sequential addition of Gal to the Man alpha 1,3-branch followed by addition to the Man alpha 1,6-branch. The preferential galactosylation of the GlcNAc beta 1,2-Man alpha 1,3-branch may explain the formation of the asymmetrical oligosaccharides found in bovine and human IgG.
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PMID:Branch specificity of purified rat liver Golgi UDP-galactose: N-acetylglucosamine beta-1,4-galactosyltransferase. Preferential transfer of of galactose on the GlcNAc beta 1,2-Man alpha 1,3-branch of a complex biantennary Asn-linked oligosaccharide. 642 77

Double-headed aspirin [bis(3,5-dibromosalicyl)fumarate] selectively cross-links hemoglobin molecules between Lys 82 beta 1 and Lys 82 beta 2 and increases solubility of deoxy-Hb S (Walder et al., J. Mol. Biol., 141:195, 1980 and Kikugawa et al., J. Biol. Chem., 257:7525, 1982). We reacted this reagent with the mixture of Hb A and Hb S and the mixture of Hb S and Hb York (beta 146His replaced by Pro). Cross-linked asymmetrical hybrid hemoglobins (alpha 2 beta - beta S and alpha 2 beta Y - beta S) were produced in high yields in addition to the cross-linked parent hemoglobin molecules. Results on electrophoresis, gel electrofocusing, ion exchange column chromatography, mechanical stability and oxygen binding properties showed that the cross-linked asymmetrical hybrid hemoglobins had properties intermediate between those of the cross-linked parent hemoglobins. Oxygen affinities of the cross-linked asymmetrical hybrids were not affected by the addition of 2,3-diphosphoglycerate (DPG) or inositol hexaphosphate, probably due to the presence of a fumaryl group at the DPG binding site.
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PMID:Formation of cross-linked asymmetrical hybrid hemoglobins by double-headed aspirin. 666 87

Plasma membrane insulin receptors, affinity labeled by covalent crosslinking to receptor-bound 125I-labeled insulin, are shown to appear as a heterogeneous population of three major disulfide-linked complexes (Mr 350,000, 320,000, and 290,000) upon electrophoresis in highly porous dodecyl sulfate/polyacrylamide gels in the absence of reductant. This pattern is consistent in all rat and human tissues that were analyzed. Upon reduction of disulfide bonds, each of these receptor structures is dissociated in two successive steps. Low concentrations of dithiothreitol promote a first step of disulfide bond reduction in which the Mr 350,000 species splits into a Mr 210,000 form and the Mr 290,000 species splits into a Mr 160,000 form. In contrast, both the Mr 210,000 and Mr 160,000 receptor fragments are generated from the native Mr 320,000 species upon partial reduction, indicating an asymmetrical structure. The second step of receptor reduction occurs upon treatment of the native disulfide-linked receptor complexes with high concentrations of dithiothreitol. Under these conditions, the Mr 350,000 receptor yields a Mr 125,000 subunit, denoted as alpha, and a Mr 90,000 subunit, denoted as beta, whereas the Mr 290,000 receptor dissociates into the alpha subunit and a Mr 49,000 subunit, denoted as beta 1. The Mr 320,000 receptor band is found to consist of alpha, beta, and beta 1 subunits upon complete reduction. The partially reduced Mr 210,000 receptor fragment is composed of the alpha subunit disulfide-linked to the beta subunit, whereas the Mr 160,000 species consists of the alpha subunit disulfide-linked to the beta 1 subunit. Thus, the stoichiometry of the three ubiquitous native insulin receptor structures of Mr 350,000, 320,000, and 290,000 are (alpha) 2 (beta) 2, (alpha) 2 (beta) (beta 1), and (alpha) 2 (beta 1) 2, respectively.
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PMID:Electrophoretic resolution of three major insulin receptor structures with unique subunit stoichiometries. 693 60