Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.27.1 (RNase)
 16,360 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Transglutaminase from guinea pig liver catalyzed the formation of cross-links between fibrinogen (or fibrin) and ribonuclease. Using transglutaminase, immoblized ribonuclease was prepared by two separate methods: (1) fibrinogen-ribonuclease conjugates formed by transglutaminase were treated with thrombin to make fibrin membrane bound covalently to the enzyme; (2) fibrin polymer formed from fibrinogen with thrombin was covalently bound to ribonuclease by transglutaminase to make fibrin-ribonuclease conjugates.
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PMID:Fibrin membrane endowed with biological function. IV. Formation of cross-links between fibrinogen (or fibrin) and ribonuclease by transglutaminase. 3 50

Elafin was shown to be a new type of proteinase inhibitor which has an anchoring sequence. Human elafin, a potent inhibitor specific for elastase and proteinase 3, has a unique repeating sequence in its prosegment that is rich in Gln and Lys residues. The prosegment, termed "cementoin," exhibits high homology with the repetitive element of seminal vesicle clotting protein, which is known as a good substrate for prostate transglutaminase. The cross-linking of cementoin by tissue transglutaminase showed that the cementoin moiety is indeed a preferable substrate for transglutaminase. In addition, transglutaminase-mediated cross-linking between cementoin and laminin was observed in vitro, suggesting that cementoin has the ability to covalently attach to other extracellular matrix proteins. To determine whether or not this type of covalent gluing of elafin through the cementoin moiety occurs in vivo, we determined the molecular size of cementoin-elafin in the trachea mucous epithelium by Western blotting; the rationale of this approach is that (i) the trachea is the richest source of cementoin-elafin, as shown below, and (ii) if cementoin-elafin is covalently associated with other proteins, it should migrate as a higher M(r) species on SDS-polyacrylamide gel electrophoresis; cementoin-elafin immunoreactivity was indeed detected at a position corresponding to 50 kDa, a value much higher than that of its monomeric form. RNase protection analysis and immunohistochemical staining revealed that cementoin-elafin is densely distributed in the skin and trachea, and moderately in the stomach, duodenum and small intestine. These sites of localization are consistent with the locations where elastic fibers are abundant.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Elastase inhibitor elafin is a new type of proteinase inhibitor which has a transglutaminase-mediated anchoring sequence termed "cementoin". 791 20

SPAI, originally isolated as a sodium/potassium-ATPase inhibitor and now considered to be a proteinase inhibitor of unknown specificity based on its similarity to elafin (an elastase inhibitor), is a new type of plasma protein that has a transglutaminase substrate domain, which serves as an anchoring sequence to be covalently cross-linked at target sites. To determine the source of SPAI, we carried out in situ hybridization and immunohistochemistry using an antisense cRNA probe and an antiserum against recombinant SPAI, respectively. Since previous RNase protection analysis had indicated that SPAI mRNA is almost exclusively expressed in the porcine small intestine, we used its frozen sections for the staining. The lower crypt was decorated with both the cRNA probe and antiserum, indicating that SPAI is synthesized and secreted by the enteroendocrine cells located near the crypt base. The native form of SPAI was also characterized by Western blotting. This result together with the previous biochemical and molecular biological characterizations may set the stage for identifying the physiological roles of the conceptually very interesting protein SPAI.
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PMID:Cryptic origin of SPAI, a plasma protein with a transglutaminase substrate domain and the WAP motif, revealed by in situ hybridization and immunohistochemistry. 893 75

The human epithelial proteinase inhibitor SKALP/elafin and the porcine sodium-potassium ATPase inhibitor SPAI-2 are two highly homologous proteins that share an NH2-terminal transglutaminase substrate domain and a COOH-terminal whey acidic protein (WAP) domain. Here we describe the bovine and simian orthologs of SKALP/elafin as well as two new bovine family members that are designated Trappin-4 and Trappin-5 on the basis of a new nomenclature that we propose (Trappin = TRansglutaminase substrate and WAP motif-containing ProteIN). Sequence analysis of Trappin-4 and Trappin-5 revealed a domain structure that is very similar to SPAI-2 (Trappin-1) and SKALP/elafin (Trappin-2). The transglutaminase substrate motifs are conserved although the number of repeats varies among species and among family members. The sequence of Trappin-4 and Trappin-5 diverges from Trappin-1 and Trappin-2 at the putative reactive site in the WAP domain. The bovine ortholog of Trappin-2 is expressed in tongue and snout epidermis; Trappin-4 is expressed in trachea, ileum, and tongue; and Trappin-5 is expressed at low levels in trachea, as determined by RNase protection and Northern blot analysis. Based on the analysis of 67 transglutaminase substrate repeats as present in all known Trappin gene family members from four different mammalian species a consensus sequence could be established: Gly-Gln-Asp-Pro-Val-Lys (GQDPVK). Using biotinylated hexapeptide probes we found that the GQDPVK sequence is a very efficient transglutaminase substrate both for guinea pig liver transglutaminase and for epidermal transglutaminase, and it acts as acyl donor as well as acceptor. We propose that the Trappin protein family forms a new group of enzyme inhibitors with various specificities of the WAP domain, which share transglutaminase substrate motifs that can act as an anchoring sequence.
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PMID:Identification and sequence analysis of two new members of the SKALP/elafin and SPAI-2 gene family. Biochemical properties of the transglutaminase substrate motif and suggestions for a new nomenclature. 925 57

We have found that ribonuclease S-peptide can work as a novel peptidyl substrate in protein cross-linking reactions catalyzed by microbial transglutaminase (MTG) from Streptomyces mobaraensis. Enhanced green fluorescent protein tethered to S-peptide at its N-terminus (S-tag-EGFP) appeared to be efficiently cross-linked by MTG. As wild-type EGFP was not susceptible to cross-linking, the S-peptide moiety is likely to be responsible for the cross-linking. A site-directed mutation study assigned Gln15 in the S-peptide sequence as the sole acyl donor. Mass spectrometric analysis showed that two Lys residues (Lys5 and Lys11) in the S-peptide sequence functioned as acyl acceptors. We also succeeded in direct monitoring of the cross-linking process by virtue of fluorescence resonance energy transfer (FRET) between S-tag-EGFP and its blue fluorescent color variant (S-tag-EBFP). The protein cross-linking was tunable by either engineering S-peptide sequence or capping the S-peptide moiety with S-protein, the partner protein of S-peptide for the formation of ribonuclease A. The latter indicates that S-protein can be used as a specific inhibitor of S-peptide-directed protein cross-linking by MTG. The controllable protein cross-linking of S-peptide as a potent substrate of MTG will shed new light on biomolecule conjugation.
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PMID:S-peptide as a potent peptidyl linker for protein cross-linking by microbial transglutaminase from Streptomyces mobaraensis. 1264 45

Specific peptidyl linkers that result in the heterodimerization of functional proteins, which is catalyzed by microbial transglutaminase from Streptomyces mobaraensis (MTG), were generated based on a ribonuclease S-peptide using site-directed mutagenesis. The peptidyl linkers designated as Lys-tag and Gln-tag were designed to possess sole reactive Lys or Gln residue that was amenable for selective Lys-Gln cross-linkage of different proteins. Green fluorescent protein variants, ECFP and EYFP, were employed as model proteins, and those Lys- and Gln-tags were fused to the N-termini of ECFP and EYFP, respectively. As a result, we succeeded in solely obtaining the ECFP-EYFP heterodimer without forming multiply cross-linked byproducts. It was found that the reactivity of peptidyl linkers varied according to the type of amino acid to be replaced. Peptidyl linkers with a basic amino acid (Arg) exhibited the highest reactivity in the cross-linking reaction, suggesting the cationic residue substrate preference of MTG. Kinetic analysis utilizing fluorescent resonance energy transfer (FRET), that is only observed upon the heterodimeric ECFP-EYFP conjugation, revealed that the amino acid replacement contributed to the acceleration of cross-linking reactions by increasing catalytic turnover (k(cat)), rather than substrate binding affinity (K(m)). Finally, using a ribonuclease S-protein, the manipulation of enzymatic protein cross-linking based on specific S-peptide:S-protein interactions was explored. Since newly designed Lys- and Gln-tags retained binding affinities to the S-protein, the heterodimerization was perfectly restrained by wrapping them with the S-protein. The results suggest the possibility of limited protein conjugation by tuning steric hindrance against the MTG. Tailoring enzymatic posttranslational modifications with either engineering peptidyl substrates or by taking specific peptide-protein interactions into consideration may facilitate the development of a new sequential protein conjugation method for the preparation of multifunctional protein.
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PMID:Peptidyl linkers for protein heterodimerization catalyzed by microbial transglutaminase. 1514 76

Onconase (Onc), is a novel amphibian cytotoxic ribonuclease with antitumor activity, and is currently in a confirmatory phase III clinical trial for the treatment of malignant mesothelioma. It was recently reported that Rana pipiens oocytes contain still another ribonuclease, named Amphinase (Amph). Amph shows 38-40% amino acid sequence identity with onconase, presents as four variants varying between themselves from 87-99% in amino acid sequence identity and has a molecular mass approximately 13,000. In the present study we describe the effects of Amph on growth of several tumor cell lines. All four variants demonstrated cytostatic and cytotoxic activity against human promyelocytic HL-60-, Jurkat T-cell- and U-937 monocytic leukemia cells. The pattern of Amph activity to certain extent resembled that of Onc. Thus, cell proliferation was suppressed at 0.5-10.0 mug/ml (40-80 nM) Amph concentration with distinct accumulation of cells in G(1) phase of the cell cycle. In addition, the cells were undergoing apoptosis, which manifested by DNA fragmentation (presence of "sub-G1" cells, TUNEL-positivity), caspases and serine proteases activation as well as activation of transglutaminase. The cytostatic and cytotoxic effects of Amph required its ribonuclease activity: the enzymatically inactive Amph-2 having histidine at the active site alkylated was ineffective. The effectiveness and cell cycle specificity was generally similar for all four Amph variants and at the equimolar concentrations was somewhat more pronounced than that of Onc. The observed cytostatic and cytotoxic activity of Amph against tumor cell lines suggests that similar to Onc this cytotoxic ribonuclease may have antitumor activity and find an application in clinical oncology.
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PMID:Cytostatic and cytotoxic properties of Amphinase: a novel cytotoxic ribonuclease from Rana pipiens oocytes. 1807 26

Tissue transglutaminase was reported to act as protein disulfide isomerase (PDI). We studied whether plasma transglutaminase - coagulation factor XIII (FXIII) - has PDI activity as well. PDI activity was measured by determining the ability to renature reduced-denatured RNase (rdRNase). We found that FXIII can renature rdRNase, with efficiency comparable to commercial PDI. This PDI activity was inhibited by bacitracin. Like tissue transglutaminase, FXIII-mediated PDI activity is independent of its transglutaminase activity and is located on the A subunit. Surface-associated PDI has been previously shown to catalyse two distinct functions: transnitrosation with subsequent release of intracellular nitric oxide and disulfide bond rearrangement during platelet integrin ligation. Our results imply that FXIII-PDI activity may have a role in platelet function.
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PMID:Coagulation factor XIII serves as protein disulfide isomerase. 1940 36

Small membrane-bound extracellular organelles known as articular cartilage matrix vesicles (ACVs) participate in pathologic mineralization in osteoarthritic articular cartilage. ACVs are also present in normal cartilage, although they have no known functions other than mineralization. Recently, RNA was identified in extracellular vesicles derived from mast cells, suggesting that such vesicles might carry coding information from cell to cell. We found that ACVs from normal porcine and human articular cartilage and primary chondrocyte conditioned media contained 1 microg RNA/80 microg ACV protein. No DNA could be detected. RT-PCR of ACV RNA demonstrated the presence of full length mRNAs for factor XIIIA, type II transglutaminase, collagen II, aggrecan, ANKH and GAPDH. RNA in intact ACVs was resistant to RNase, despite the fact that ACV preparations contained measurable levels of active RNases. Significantly, radiolabeled RNA in ACVs could be transferred to unlabeled chondrocytes by co-incubation and produced changes in levels of chondrocyte enzymes and proteins. The demonstration that ACVs contain mRNAs suggests that they may function to shuttle genetic information between articular cells and indicate novel functions for these structures in articular cartilage.
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PMID:Articular cartilage vesicles contain RNA. 1967

Self-incompatibility (SI) is a complex process, one out of several mechanisms that prevent plants from self-fertilizing to maintain and increase the genetic variability. This process leads to the rejection of the male gametophyte and requires the co-participation of numerous molecules. Plants have evolved two distinct SI systems, the sporophytic (SSI) and the gametophytic (GSI) systems. The two SI systems are markedly characterized by different genes and proteins and each single system can also be divided into distinct subgroups; whatever the mechanism, the purpose is the same, i.e., to prevent self-fertilization. In Malinae, a subtribe in the Rosaceae family, i.e., Pyrus communis and Malus domestica, the GSI requires the production of female determinants, known as S-RNases, which penetrate the pollen tube to interact with the male determinants. Beyond this, the penetration of S-RNase into the pollen tube triggers a series of responses involving membrane proteins, such as phospholipases, intracellular variations of cytoplasmic Ca2+, production of reactive oxygen species (ROS) and altered enzymatic activities, such as that of transglutaminase (TGase). TGases are widespread enzymes that catalyze the post-translational conjugation of polyamines (PAs) to different protein targets and/or the cross-linking of substrate proteins leading to the formation of cross-linked products with high molecular mass. When actin and tubulin are the substrates, this destabilizes the cytoskeleton and inhibits the pollen-tube's growth process. In this review, we will summarize the current knowledge of the relationship between S-RNase penetration, TGase activity and cytoskeleton function during GSI in the Malinae.
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PMID:Cytoskeleton, Transglutaminase and Gametophytic Self-Incompatibility in the Malinae (Rosaceae). 3062 63


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