Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.27.4 (ribonuclease)
 6,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bacteriocin-like substances were commonly produced by slow-growing Rhizobium japonicum and cowpea rhizobia on an L-arabinose medium. Antagonism between strains of R. japonicum was not detected in vitro; however, such strains were often sensitive to some bacteriocins produced by cowpea rhizobia. Inhibitory zones (2 to 8 mm from colony margins), produced by 58 of 66 R. japonicum test strains, were reproducibly detected with Corynebacterium nebraskense as an indicator. Quantitative production was not related to symbiotic properties of effective strains, since nine noninfective strains and one ineffective strain produced bacteriocin. Eight R. japonicum strains that did not produce bacteriocin nevertheless formed effective nodules on soybeans. R. japonicum strains that produced bacteriocin in vitro had no antagonistic effect on nonproducer strains during soybean nodulation. Under controlled conditions, a nonproducer (3I1b135) predominated over a bacteriocin producer (3I1b6) when inoculated at 1:1 and 1:9 ratios. Depending on the particular ratio, up to 38% of the total nodules formed were infected with mixed combinations. The bacteriocin(s) had a restricted host range and antibiotic-like properties which included the ability to be dialyzed and resistance to heat (75 to 80 degrees C, 30 min), Pronase, proteinase K, trypsin, ribonuclease, and deoxyribonuclease. R. japonicum strains representing genetic, serological, cultural, and geographic diversity were differentiated into three groups on the basis of bacteriocin production.
 ...
PMID:Bacteriocin-like substances produced by Rhizobium japonicum and other slow-growing rhizobia. 57 16

Mannose-specific binding sites for horseradish peroxidase (HRP) were studied in fixed sections of various tissues by a method reported previously. Liver sinusoidal cells, mast cells of lymph nodes, and alveolar macrophages of the lung and skin fibroblasts were main cell types showing mannose-specific binding of HRP. Macrophages, fibroblasts, and mast cells in the connective tissue of other organs also showed the reaction. However, macrophages of the spleen, and cultured 3T3 cells and L-cells did not give the reaction. The specificities of the binding reaction were studied by determining the approximate concentrations of competing sugars that suppressed the specific binding of HRP. It was found that the endogenous lectins in macrophages, fibroblasts, mast cells, and liver sinusoidal cells showed similar specificities toward various carbohydrates. D-Mannose and L-fucose had the highest affinity toward the lectins (competing ability for the binding of HRP). D-Mannose-6-phosphate, N-acetyl-D-glucosamine, D-glucose, D-ribose, and D-arabinose showed intermediate affinity, whereas D-xylose and D-galactose showed low affinity. Polymerized mannose in mannan and glycoproteins rich in mannose groups (invertase and ribonuclease B) showed much higher affinity to the binding sites than free mannose.
 ...
PMID:Mannose-specific binding sites for horseradish peroxidase in various cells of the rat. 683 41

Ribonuclease B has become a paradigm as a simple example of an N-linked glycoprotein. We have found that certain affinity-purified preparations of this enzyme demonstrated a pronounced tendency to lose activity if stored as dilute aqueous solutions. Such inactivation is accelerated by the presence of NaCl, but can be counteracted by inclusion of high (1 mol/l) concentrations of xylose. Enzyme activity cannot be restored by addition of xylose after storage of the enzyme. In marked contrast to alpha-methyl-mannoside, xylose does not prevent ribonuclease B from binding to concanavalin A and so may be used to stabilize the enzyme during purification by lectin affinity chromatography.
 ...
PMID:Stabilization of ribonuclease B activity by concentrated xylose solutions. 785

Syringacin 4-A, a bacteriocin produced by Pseudomonas syrinagae 4-A, was obtained by induction with ultraviolet irradiation or mitomycin C. Approximately 1,000-fold purification of the bacteriocin was achieved by manganous chloride precipitation, differential centrifugation, and chromatography on hydroxyapatite columns. The purified syngacin was homogeneous on hydroxyapatite columns and sucrose density gradients; it also sedimented as a single entity in the analytical ultracentrifuge. The buoyant density of purified syringacin in cesium chloride was 1.294 g/ml. The sedimentation coefficient was calculated as 120S, and the diffusion coefficient was 6.49 x 10(-8) cm(2)/s. The molecular weight was calculated as 1.6 x 10(7) from physical data and 1.7 x 10(7) from biological data. The syringacin was composed of about 88.4% protein, 8.5% arabinose, 2.2% galacturonic acid, and 0.7% glucosamine. Amino acid analysis indicated a predominance of leucine (12.1%), aspartic acid (12.2%), and glutamic acid (12.7%). The ultraviolet spectrum showed a maximum absorbance peak at 276 nm. The syringacin was heat and alcohol sensitive, but resistant to trypsin, chymotrypsin, carboxypeptidase, Pronase, protease, lysozyme, steapsin, deoxyribonuclease, and ribonuclease. Maximum pH stability was between 5 and 8. Crude bacteriocin was stable at room temperature for at least a year, and purified material was stable for at least 3 months at 4 C.
 ...
PMID:Purification and characterization of syringacin 4-A, a bacteriocin from pseudomonas syringae 4-A. 1582 74

A pathogenesis-related (PR) class 10 protein (designated AmPR-10) was first isolated from the Chinese medicinal material Astragalus mongholicus using a combination of affinity chromatography on Zn-chelate Agarose 4B, ion exchange chromatography on QAE Sephadex A-25 and gel filtration on Sephadex G50. The purified AmPR-10 showed a single band with a molecular mass of 17.2kDa in SDS-PAGE. The molecular mass of intact AmPR-10 was determined to be 32.8kDa by gel filtration. Thus, AmPR-10 is a dimeric protein composed of two identical subunits. AmPR-10 was a glycoprotein detected by periodic acid-Schiff (PAS) staining and its neutral carbohydrate content was 13.7%. The carbohydrate was mainly composed of 73.0% (w/w) arabinose, 15.0% (w/w) glucose and 4.8% (w/w) fructose on the basis of high-performance anion exchange chromatography (HPAEC) analysis. Its N-terminal sequence of 15 amino acid residues was determined as GVISFNEETISTVAP, and showed significant sequence homology to some pathogenesis-related (PR) class 10 proteins. This sequence had 80% identity with the PR-10 protein LlPR10.1C from Lupinus luteus (yellow lupine) followed by 73.3% identity with the PR-10 protein PR10.2 from Medicago sativa (alfalfa), suggesting it is a new member of PR-10 proteins. AmPR-10 exhibited ribonuclease (RNase) activity as do some other PR-10 proteins. The optimal pH and temperature for RNase activity were pH 6.0 and 60 degrees C, respectively. The RNase activity was stable within pH 5.0-11.0. It was stable up to 60 degrees C at pH 6.0. The purification and characterization of AmPR-10 in this investigation furnish additional data to the relatively scanty literature pertaining to Astragali radix proteins.
 ...
PMID:Characterization of a pathogenesis-related class 10 protein (PR-10) from Astragalus mongholicus with ribonuclease activity. 1802 44