Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.5.1.52 (PNGase F)
 1,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Time course digestion of intact human erythrocytes and right side-out vesicles with carboxypeptidase Y altered the Rh polypeptides and removed the 125I label that is normally incorporated by cell-surface radioiodination, but did not affect the RhD, Rhc, or RhE antigens. Under the same conditions, however, the LW antigens were rapidly destroyed. Digestion of inside-out and right side-out vesicles with aminopeptidase M was without any detectable effect on the Rh and LW antigens or polypeptides, although glycophorin A was degraded from right side-out but not from inside-out vesicles. These findings demonstrate that the C-terminal domain of the Rh and LW polypeptides is exposed at the external surface of human erythrocytes and indicate, in addition, that the LW antigens and tyrosine residue(s) of the LW and Rh proteins, respectively, are located close to the C termini of these polypeptides. Further studies using monoclonal and polyclonal antibodies showed that LW antigen expression is inhibited by treatment of red cells with EDTA and is selectively restored by Mg2+, but not by Mn2+ or Ca2+, whereas the Rh antigens were not affected under these conditions. In addition, O- and N-glycanase digestion of the LW glycoprotein removed its sugar chains, but did not alter significantly the epitopes recognized by the monoclonal anti-LW antibody.
 ...
PMID:Surface orientation and antigen properties of Rh and LW polypeptides of the human erythrocyte membrane. 197 26

Many of the extracellular lignin-degrading peroxidases from the wood-degrading fungus Phanerochaete chrysosporium are phosphorylated. Immunoprecipitation of the extracellular fluid of cultures grown with H2K32PO4 with a polyclonal antibody raised against one of the lignin peroxidase isozymes, H8 (pI 3.5), revealed the incorporation of H2K32PO4 into lignin peroxidases. Analyses of the purified isozymes from labeled cultures by isoelectric focusing showed that, in addition to isozyme H8, lignin peroxidase isozymes H2 (pI 4.4), H6 (pI 3.7), and H10 (pI 3.3) are also phosphorylated. These analyses also showed that lignin peroxidase isozyme H1 (pI 4.7) and manganese-dependent peroxidase isozymes H3 (pI 4.9) and H4 (pI 4.5) are not phosphorylated. Phosphate quantitation indicated the presence of one molecule of phosphate/molecule of enzyme for all of the phosphorylated isozymes. To locate the site of phosphorylation, one-dimensional phosphoamino acid analysis was performed with hydrolyzed 32P-protein. However, phosphotyrosine, phosphoserine, and phosphothreonine could not be identified. Coupled enzyme assays of acid hydrolysate indicated the presence of mannose 6-phosphate as the phosphorylated component on the lignin peroxidase isozymes. Digestion of the isozymes with N-glycanase released the phosphate component, indicating that the mannose 6-phosphate is contained on an asparagine-linked oligosaccharide.
 ...
PMID:Phosphorylation of lignin peroxidases from Phanerochaete chrysosporium. Identification of mannose 6-phosphate. 258 20

Lactosylceramide synthase is an enzyme that catalyzes the transfer of galactose from UDP-Gal to glucosylceramide, and thus participates in the biosynthesis of most glycosphingolipids in mammals. We purified this enzyme over 61,000-fold to near homogeneity with a 29. 7% yield from rat brain membrane fractions. The isolation procedure included solubilization with Triton X-100, affinity chromatography on wheat germ agglutinin-agarose and UDP-hexanolamine-agarose, and hydroxylapatite column chromatography, followed by ion exchange chromatography. The final preparation migrated as a broad band with an apparent molecular mass of 61 kDa on SDS-polyacrylamide gel electrophoresis. This apparent molecular mass was reduced to 51 kDa by N-glycanase digestion, suggesting that the enzyme has a glycoprotein nature. The enzyme required Mn2+ for its activity, and glucosylceramide was its preferred substrate. The cDNA for the enzyme was cloned from a rat brain cDNA library. The cDNA insert encoded a polypeptide of 382 amino acid residues, with a molecular weight of 44,776. The polypeptide contained eight putative glycosylation sites and a 20-amino acid residue transmembrane domain at its N terminus. Amino acid sequence homology analysis revealed that this enzyme shared 39% homology with mouse beta-1, 4-galactosyltransferase (EC 2.4.1.38), which catalyzes the transfer of Gal to beta-1,4-GlcNAc in glycoproteins.
 ...
PMID:Purification, cDNA cloning, and expression of UDP-Gal: glucosylceramide beta-1,4-galactosyltransferase from rat brain. 959 93