Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.26.9 (ribonuclease)
6,589 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using synthetic oligonucleotide probes, we have cloned a genomic DNA sequence encoding a ribonuclease (RNase) T2 gene (rntB) from Aspergillus oryzae on a 4.8 kb HindIII fragment. DNA sequence analysis of the RNase T2 revealed the following: (1) The gene is arranged as five exons and four introns; (2) The deduced amino acid sequence contains 239 amino acid residues of the mature enzyme. In addition, there exist 17 amino acid residues thought to be a signal peptide sequence at the N-terminus and 20 amino acid residues at the C-terminus; (3) The nucleotide sequence of the rntB gene is homologous to those of the RNase Rh gene from Rhizopus niveus and the S2 stylar glycoprotein gene of Nicotiana alata with degree of about 51% and 47%, respectively; (4) A. oryzae and A. nidulans transformed with the cloned rntB gene had much higher ribonuclease T2 activity than wild-type strains.
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PMID:Cloning and nucleotide sequence of the genomic ribonuclease T2 gene (rntB) from Aspergillus oryzae. 191 76

Two neutral ribonucleases have been purified from developing tomato fruit. Their activity is maximal 5 days after anthesis, declines during maturation, and then increases slightly in the mature green through breaker stages. The ribonucleases Tf1 and Tf2 have molecular weights of 59 and 29 K, respectively, based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and are glycoproteins. The reduced and denatured Tf1 is composed of two subunits, 30 and 29 K, of which only the 30-K subunit displays ribonuclease activity after renaturation. Reduced and denatured Tf2 is a single 29-K polypeptide that is renaturable to an active ribonuclease. Only the 30-K, active subunit of Tf1 is immunologically cross-reactive with Tf2. Both ribonucleases are cyclyzing endoribonucleases with a strong preference for cleavage at pyrimidine residues, thus generating oligonucleotide products ending with pyrimidine 2',3'-cyclic phosphate. These tomato fruit ribonucleases share a number of properties in common with the S-glycoprotein ribonucleases that are involved in self-incompatibility reactions in some solanaceous plants.
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PMID:Purification and characterization of two ribonucleases from developing tomato fruit. 192 99

Thrombospondin (TSP) is a trimeric glycoprotein which is synthesized and incorporated into the extracellular matrix by a wide variety of cells. TSP is involved in a number of cellular processes which govern tumor cell behavior including mitogenesis, attachment, migration, and differentiation. To directly assess the role of TSP in tumor cell growth and spread, a human squamous carcinoma cell line, with high TSP production and an invasive phenotype, was transfected with a TSP cDNA antisense expression vector. Five unique transfected clones were obtained with reduced TSP production. Expression of the transfected antisense sequence in these clones was verified by a ribonuclease protection assay. These clones demonstrated reduced growth rates in vitro when compared with a vector transfected control. After subcutaneous inoculation into athymic mice, the antisense clones formed either no tumors or tumors that were slow growing and highly differentiated. This contrasted with the vector-transfected clone which produced poorly differentiated, rapidly growing, invasive tumors. Our results argue in favor of a direct role for TSP in determining the malignant phenotype of certain human tumors.
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PMID:Antisense-mediated reduction in thrombospondin reverses the malignant phenotype of a human squamous carcinoma. 204 Jun 84

A ribonuclease has been isolated from human spleen (RNase HS) by means of acid extraction, ammonium sulphate fractionation, successive column chromatographies on CM-cellulose, heparin-actigel, and poly(G)-agarose, and double gel-filtration on Sephadex G-75. The purified preparation was homogeneous as judged by SDS/PAGE. RNase HS was found to be a glycoprotein, containing three fucose, one mannose and five glucosamine residues/molecule, with a molecular mass of 17 kDa as determined by both SDS/PAGE and gel filtration. The catalytic properties and structural features, including its amino acid composition and the amino acid sequence of the N-terminal 35 residues, indicated that the enzyme was strictly related to nonsecretory RNase isolated from human urine and liver. In particular, the amino acid sequence of the N-terminal was identical with that of urine nonsecretory RNase and eosinophil-derived neurotoxin. Furthermore, analyses using three different antibodies specific to RNase HS, urine nonsecretory RNase and urine secretory RNase, indicated that RNase HS was not immunologically distinguishable from urine nonsecretory RNase, but clearly so from urine secretory RNase. However, the carbohydrate compositions of RNase HS and urine nonsecretory RNase were found to differ. It therefore remains to be resolved whether or not the tissue of origin of nonsecretory RNase in urine is the spleen.
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PMID:Purification and characterization of a ribonuclease from human spleen. Immunological and enzymological comparison with nonsecretory ribonuclease from human urine. 238 98

A fast atom bombardment mass spectrometric protocol has been developed to determine the type of oligosaccharide chain present in glycoproteins. The procedure is based on acetolysis of the intact glycoconjugate, extraction of the peracetylated carbohydrate fragments and analysis by fast atom bombardment mass spectrometry. The molecular ions present in the FAB spectra uniquely define the composition of the oligosaccharides with respect to hexose, aminohexose and sialic acid content. High mannose oligosaccharides yield a series of peracetylated hexose oligomers whereas complex-type oligosaccharides afford a series of N-acetyl-lactosamine containing species. Fucosylation is usually not detected but sialylated oligosaccharides are readily identified and the type of sialic acid is also defined. The method has been tested on three glycoproteins of known structure - fetuin, ribonuclease B and erythrocyte Band 3 - and on a glycoprotein of unknown structure - alpha-galactosidase I, an enzyme lectin from Vicia faba. The latter is shown to contain high mannose carbohydrate chains.
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PMID:A novel mass spectrometric procedure for the rapid determination of the types of carbohydrate chains present in glycoproteins: application to alpha-galactosidase I from Vicia faba seeds. 241 21

The effects of treatments of the glycoprotein ribonuclease-B, the proteins ribonuclease-A and myoglobin, and the glyco-amino acid GlcNAc beta(1-N)Asn with alkali, alkaline sodium borohydride, and aqueous sodium borohydride were systematically studied as a function of the concentration of the reagents, the temperature, and the length of the treatment. High-field 1H-NMR spectroscopy, chromatographic methods and amino-acid analysis were used to characterize products of the treatments of the various compounds. Our results indicate that mild alkaline borohydride treatment, as well as aqueous borohydride treatment alone, is capable of extensively degrading polypeptides and of partially releasing the N-linked glycans from ribonuclease-B. Initially, glycopeptides are produced, the peptide portion of which consists of several amino acids, which are further hydrolyzed to yield a mixture of glyco-asparagines and oligosaccharide-alditols in the ratio of approximately 4:1. Strong alkaline borohydride treatment of ribonuclease-B is capable of completely releasing the N-linked carbohydrates as oligosaccharide-alditols.
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PMID:The effect of alkaline borohydride treatment on N-linked carbohydrates of glycoproteins. 253 76

A T1 ribonuclease fingerprinting study of a large number of virus isolates had previously demonstrated that considerable genetic variability existed among natural isolates of the vesicular stomatitis virus (VSV) New Jersey (NJ) serotype [S.T. Nichol (1988) J. Virol. 62, 572-579]. Based on these results, 34 virus isolates were chosen as representing the extent of genetic diversity within the VSV NJ serotype. We report the entire glycoprotein (G) gene nucleotide sequence and the deduced amino acid sequence for each of these viruses. Up to 19.8% G gene sequence differences could be seen among NJ serotype isolates. Analysis of the distribution of nucleotide substitutions relative to nucleotide codon position revealed that third position changes were distributed randomly throughout the gene. Third base changes constituted 84% of the observed nucleotide substitutions and affected 89% of the third base positions located in the G gene. Only three short oligonucleotide stretches of complete sequence conservation were observed. The remaining nucleotide changes located in the first and second positions were not distributed randomly, indicating that most of the amino acids coded by the G gene cannot be altered without reducing the fitness of the VSV NJ serotype viruses. Despite these constraints, up to 8.5% amino acid differences were observed between virus isolates. These differences were located throughout the G protein including regions adjacent to defined major antibody neutralization epitopes. Apparent clusters of amino acid substitutions were present in the hydrophobic signal sequence, transmembrane domain, and within the cytoplasmic domain of the G protein. A maximum parsimony analysis of the G gene nucleotide sequences allowed construction of a phylogram indicating the evolutionary relationship of these viruses. The VSV NJ serotype appears to contain at least three distinct lineages or subtypes. All recent virus isolates from the United States and Mexico are within subtype I and appear to have evolved from an ancestor more closely related to the Hazelhurst historic strain than other older strains. The implications of these findings for the evolution, epizootiology, and classification of these viruses are discussed.
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PMID:Glycoprotein evolution of vesicular stomatitis virus New Jersey. 253 83

Haraldsson and Rippe suggested that the circulating glycoprotein orosomucoid (alpha 1-acid glycoprotein) contributes to the net charge on microvessel walls (Acta Physiol. Scand. 129: 127-135, 1987). We tested their hypothesis in individually perfused microvessels of frog mesentery by measuring solute permeability coefficients of two globular proteins (alpha-lactalbumin and ribonuclease) having approximately the same size (Stokes radius, 2 nm) but different charge (-11 and +3, respectively). In vessels perfused with orosomucoid (0.1 and 1 mg/ml) in a Ringer-albumin perfusate, the solute permeability coefficient of alpha-lactalbumin decreased to one-half [0.47 +/- 0.25 (SD)] the value in the absence of orosomucoid, and the solute permeability coefficient of ribonuclease was close to six times as large as alpha-lactalbumin permeability. Both results may be accounted for if orosomucoid increases the net negative charge on microvessel walls in frog mesentery from 11.2 to 28 meq/l. A similar change in microvessel charge would be more than sufficient to account for the decrease in albumin clearance in the presence of orosomucoid reported by Haraldsson and Rippe in rat muscle microvessels.
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PMID:Modulation of microvessel wall charge by plasma glycoprotein orosomucoid. 258 90

The primary gene transcript for the adhesive extracellular matrix glycoprotein fibronectin (FN) is alternatively spliced in three regions (EIIIA, EIIIB and V). At least one of these regions (V) has been shown to encode cell-binding sites, suggesting that splicing represents a mechanism to create functionally different forms of FN at different times and places. In order to test this hypothesis, we have examined the extent of alternative splicing of fibronectin during embryonic development. The distribution of the different spliced forms of FN mRNA in developing chicken embryos was determined using probes specific for the spliced regions in ribonuclease protection and in situ hybridization experiments. At embryonic day 2-4 (E2-4), all three spliced regions were included wherever FN mRNA was detected. At E16, however, we found spatially distinct splicing differences within the embryo, with cell-type-specific splicing excluding EIIIA and/or EIIIB in some tissues. In contrast, we did not detect exclusion of the V region. In a more detailed developmental study of the simplest of these tissues, the chorioallantoic membrane, we found that EIIIB was preferentially excluded after the completion of growth. These results suggest that FN splicing is used during development as a mechanism to create different forms of FN within the extracellular matrix by the inclusion or exclusion of specific segments. The data are consistent with an essential role for one of these segments, EIIIB, in the migration and/or proliferation of embryonic cells prior to their terminal differentiation and also suggest possible roles for the EIIIA segment.
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PMID:Alternative splicing of fibronectin is temporally and spatially regulated in the chicken embryo. 259 21

A new and previously undescribed glycoprotein with a molecular weight of 43,000 has been isolated from human urine. This protein, designated GP43; copurified with ribonuclease, which has the same molecular weight, but ribonuclease activity was removed by passage through an affinity column of agarose-5'-(4-aminophenyl phosphoryl) uridine 2'(3') phosphate. GP43 contains about 5.9% neutral sugar, 2.3% hexosamine, and 1.6% sialic acid. A rabbit antibody to the purified GP43 reacted with human urine and serum as well as with the purified GP43. The genetic polymorphism of GP43 was then studied in desialylated human serum samples by urea-polyacrylamide gel isoelectric focusing, followed by immunoblotting with the specific antibody for GP43. Three common phenotypes, designated GP43 1, 1-2, and 2, were easily recognized using this technique and represented homozygosity or heterozygosity for two autosomal codominant alleles, GP43*1 and GP43/2. The frequencies of the GP43*1 and GP43*2 alleles in a Japanese population were 0.7683 and 0.2317, respectively.
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PMID:Biochemical and genetic studies on GP43, a 43-kD glycoprotein detected immunologically in human urine and serum. 262 98


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