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)

Insulin-like growth factor binding protein (IGFBP) secretory profiles were determined for vascular smooth muscle cells (VSMC) derived from bovine aorta and human aorta, pulmonary artery, and coronary artery. The bovine cells produced IGFBP-4, IGFBP-3, and an IGFBP-3 protease. IGF-I stimulated messenger RNA (mRNA) and media levels of IGFBP-3. The human cells produced IGFBP-3, IGFBP-4, and IGFBP-3 and IGFBP-4 proteases. The three human cells also produced a 30K IGFBP, shown to be IGFBP-6, based on increased affinity for IGF-II vs. IGF-I, size decrease when treated with O-glycanase, but not N-glycanase, reactivity with IGFBP-6 antiserum, presence of a 1.3-kilobase pair mRNA that hybridized to IGFBP-6 specific complementary DNA, and N-terminal amino acid sequence corresponding to IGFBP-6. In the human cells, IGF-I increased media levels of IGFBP-3 through stimulation of IGFBP-3 mRNA and dissociation of cell bound IGFBP-3, and decreased IGFBP-4 via potentiation of IGFBP-4 proteolysis. Neither the bovine nor the human aorta VSMC produced sufficient IGFBP-2 or IGFBP-2 mRNA to be detected by ligand blot and Northern analysis, as previously reported for porcine and rat aorta smooth muscle cells. The variable expression of IGFBPs and IGFBP proteases by VSMC are likely to contribute to differential vascular reactivity to the IGFs in larger arterial blood vessels.
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PMID:Insulin-like growth factor binding protein production by bovine and human vascular smooth muscle cells: production of insulin-like growth factor binding protein-6 by human smooth muscle. 894 Mar 57

Autoantibodies to a 64-kD protein and a 40-kD tryptic fragment from pancreatic islets have been detected at high frequency in the sera of patients with insulin-dependent diabetes mellitus (IDDM). IA-2, a newly isolated transmembrane protein tyrosine phosphatase, is a major islet cell autoantigen in IDDM and the precursor of a 40-kD tryptic fragment. To express large quantities of recombinant IA-2 protein and analyse post-translational modifications we expressed full-length human IA-2 in baculovirus-infected Sf-9 cells. IA-2 expression was analysed by Western blot and by immunoprecipitation of 35S-methionine-radiolabelled proteins with rabbit antisera or IDDM sera. A 120-kD IA-2 protein was detected during the early, but not the late, phase of the infection. Pulse-chase experiments showed that the 120-kD protein was processed into fragments of 64 kD and smaller fragments of approximately 50 kD, 38 kD and 32 kD. The 64-kD fragment appeared as a doublet. Tunicamycin and PNGase F treatment down-shifted the 120-kD protein and the 64-kD doublet into lower molecular weight bands, suggesting that both were glycosylated. Trypsin treatment converted the 120-kD protein and the 64-kD doublet into a 40-kD fragment. Baculovirus-expressed IA-2 was as sensitive or slightly more sensitive than in vitro translated IA-2 in detecting autoantibodies to IA-2: 66% of sera from newly diagnosed IDDM patients reacted with baculovirus-expressed IA-2 compared with 59% of the same sera which reacted with in vitro translated IA-2. It is concluded that baculovirus-expressed IA-2 is a good source of autoantigen and that a number of lower molecular weight fragments with which IDDM autoantibodies react are derived from the 120-kD full-length IA-2 molecule.
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PMID:Expression, characterization, processing and immunogenicity of an insulin-dependent diabetes mellitus autoantigen, IA-2, in Sf-9 cells. 973 64

The growth hormone receptor (GHR) cDNA was cloned from the liver of soft-shelled turtle (Pelodiscus sinensis japonicus) using the polymerase chain reaction (PCR). Although GHR has been cloned from several mammalian and avian species, this is the first description of the reptilian receptor. As deduced from the nucleotide sequence, the precursor GHR of soft-shelled turtle (tGHR) is a protein of 615 amino acids which presents 72% identity with the chicken receptor and 57-64% identity with GHRs of several mammals. The tGHR expressed in COS-7 cells specifically bound human growth hormone (hGH) and was able to transduce an activation of transcription in the transfected cells. Binding of (125)I-hGH to the expressed receptor was decreased by the addition of excess unlabeled hGH, pig GH, and bream GH but not by pig insulin. The open reading frame of tGHR cDNA was inserted into the pSINrep/gfp (green fluorescence protein) vector and the tGHR-gfp fusion protein was stably expressed in baby hamster kidney (BHK) cells. Confocal imaging showed that tGHR-gfp was largely concentrated on the plasma membrane. Western blot analysis and deglycosylation treatment with PNGase F demonstrated that tGHR was a glycoprotein in BHK cells.
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PMID:cDNA cloning and functional expression of growth hormone receptor from soft-shelled turtle (Pelodiscus sinensis japonicus). 1101 74

A kallikrein-like proteinase of Lachesis muta muta (bushmaster) venom, designated LV-Ka, was purified by gel filtration and anion exchange chromatographies. Physicochemical studies indicated that the purified enzyme is a 33 kDa monomeric glycoprotein, the Mr of which fell to 28 kDa after deglycosylation with PNGase F. Approximately 77% of the protein sequence was determined by sequencing the various fragments derived from digestions with endoproteases. The partial sequence obtained suggests that LV-Ka is of a similar size to other serine proteinases (i.e., approximately 234 amino acid residues). Sequence studies on the NH2-terminal region of the protein indicate that LV-Ka shares a high degree of sequence homology with the kallikrein-like enzymes EI and EII from Crotalus atrox, with crotalase from Crotalus adamanteus and significant homology with other serine proteinases from snake venoms and vertebrate serum enzymes. LV-Ka showed kallikrein-like activity, releasing bradikinin from kininogen as evidenced by guinea pig bioassay. In addition, intravenous injection of the proteinase (0.8 microg/g) was shown to lower blood pressure in experimental rats. In vitro, the isolated proteinase was shown to have neither fibrin(ogeno)lytic activity nor coagulant effect. LV-Ka was active upon the kallikrein substrates S-2266 and S-2302 (specific activity=13.0 and 31.5 U/mg, respectively; crude venom=0.25 and 6.0 U/mg) but had no proteolytic effect on dimethylcasein and insulin B chain. Its enzymatic activity was inhibited by NPGB and PMSF, indicating that the enzyme is a serine proteinase. Interestingly, one of the other reactions catalyzed by plasma kallikrein, the activation of plasminogen was one of the activities exhibited by LV-Ka.
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PMID:Kallikrein-like proteinase from bushmaster snake venom. 1282 19

The pancreatic/duodenal homeobox-1 protein (PDX-1, also called STF-1, IPF-1) is a transcription factor that plays an important role in pancreatic function and development. Here, we have overexpressed and purified PDX-1 from baculovirus/sf-9 cells, transiently transfected Cos-7 cells and native Min6 cells and demonstrated that the protein is posttranslationally modified by O-linked N-acetylglucosamine (O-GlcNAc). The approaches we used include binding of the protein to the lectin WGA, labeling with galactosyltransferase and UDP-[(3)H]gal and probing with the O-GlcNAc-specific antibody, RL-2. PNGase F treatment and structural analysis indicate that the carbohydrate is beta-linked O-GlcNAc. Mapping of [(3)H]gal-labeled tryptic peptides indicates that PDX-1 has two major sites for O-GlcNAcylation. In Min6 cells, elevated glucose concentration leads to an increase in protein O-GlcNAcylation and this hyperglycosylation correlates with an increase in DNA binding activity of PDX-1 and insulin secretion. On the other hand, the GFAT inhibitor azaserine reduces intracellular O-GlcNAc levels and profoundly attenuates glucose-stimulated insulin secretion. These data suggest that O-GlcNAcylation may be involved in the regulation of PDX-1 DNA binding activity and in glucose-stimulated insulin secretion in beta-cells.
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PMID:The transcription factor PDX-1 is post-translationally modified by O-linked N-acetylglucosamine and this modification is correlated with its DNA binding activity and insulin secretion in min6 beta-cells. 1283 37


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