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

The human promyelocytic leukemia ell line, HL-60, synthesized a class of high-molecular-weight (M.W. 5000 to 7000), N-linked glycopeptides as the major class of protein-bound carbohydrates. Small glycopeptides (M.W. 2500 to 3500), typical of most mammalian cells except erythrocytes, represented a minor component in these cells. The large glycopeptides were labeled efficiently with fucose, glucosamine, and galactose but only poorly with mannose. They were found not to be glycolipids, glycosaminoglycans, or mucin-type glycopeptides and were not susceptible to exoglycosidases, but they were partially degraded by endo-beta-galactosidases. These characteristics are similar to those of the large glycopeptides synthesized by erythrocytes, by another human myeloid leukemia cell line (K562), and by human and murine teratocarcinoma cells. High-molecular-weight glycopeptides predominated on another human myeloid leukemia cell line KG1, but they were expressed at low levels on both a human monocytic leukemia cel line (THP-1) and a human T-lymphoblastoid cell line (Jurkat). When HL-60 cells were induced to differentiate into macrophage-like cells with phorbol esters, the proportion of large glycopeptides decreased, and the production of small glycopeptides predominated. This shift was observed within the first several hr after exposure to phorbol esters and was temporally related to the acquisition of adherent properties by the induced cells. In contrast, when HL-60 cells were induced to differentiate into granulocytes by dimethyl sulfoxide, hypoxanthine, or retinoic acid, they continued to synthesize glycopeptides similar to uninduced cells. Human peripheral blood granulocytes synthesized primarily large glycopeptides, whereas monocytes and lymphocytes synthesized mostly small glycopeptides. These results indicate that the synthesis of high-molecular-weight glycopeptides is a property of human myeloid leukemia cell lines and that it persists throughout myeloid differentiation. A proportionate decrease in the synthesis of these large glycopeptidase is a part of the differentiation program for monocytes and macrophages.
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PMID:Decreased synthesis of high-molecular-weight glycopeptides in human promyelocytic leukemic cells (HL-60) during phorbol ester-induced macrophage differentiation. 694 6

Staphylococcal superantigen-like proteins (SSL) show no superantigenic activity but have recently been considered to act as immune suppressors. It was previously reported that SSL5 bound to P-selectin glycoprotein ligand-1 (PSGL-1) and matrix metalloproteinase (MMP)-9, leading to inhibition of leukocyte adhesion and invasion. These interactions were suggested to depend on sialic acid-containing glycans of MMP-9, but the roles of sialic acids in the interaction between SSL5 and MMP-9 are still controversial. In the present study, we prepared recombinant glutathione S-transferase-tagged SSL5 (GST-SSL5) and analyzed its binding capacity to MMP-9 by pull-down assay after various modifications of its carbohydrate moieties. We observed that GST-SSL5 specifically bound to MMP-9 from a human monocytic leukemia cell line (THP-1 cells) and inhibited its enzymatic activity in a concentration-dependent manner. After MMP-9 was treated with neuraminidase, its binding activity towards GST-SSL5 was markedly decreased. Furthermore, recombinant MMP-9 produced by sialic acid-deficient Lec2 mutant cells showed much lower affinity for SSL5 than that produced by wild-type CHO-K1 cells. Treatment of MMP-9 with PNGase F to remove N-glycan resulted in no significant change in the GST-SSL5/MMP-9 interaction. In contrast, the binding of GST-SSL5 to MMP-9 secreted from THP-1 cells cultured in the presence of an inhibitor for the biosynthesis of O-glycan (benzyl-GalNAc) was weaker than the binding of GST-SSL5 to MMP-9 secreted from untreated cells. These results strongly suggest the importance of the sialic acid-containing O-glycans of MMP-9 for the interaction of MMP-9 with GST-SSL5.
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PMID:Role of sialic acid-containing glycans of matrix metalloproteinase-9 (MMP-9) in the interaction between MMP-9 and staphylococcal superantigen-like protein 5. 2932 25