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:2.7.7.49 (reverse transcriptase)
31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A homodimeric trypsin inhibitor with a molecular mass of 54 kDa was isolated from the seeds of Clausena lansium (Lour) Skeels with a very simple procedure comprising extraction with an aqueous buffer and ion exchange chromatography on CM-cellulose. It inhibited trypsin with an IC50 of 2.2 nM but was without any inhibitory effect on chymotrypsin and proteinase K. The uptake of MTT by human leukemia HL60 and hepatoma Hep G2 cells was inhibited with an IC50 of 100 microM. Translation in the cell-free rabbit reticulocyte lysate system was inhibited with an IC50 of 3.6 microM. The activity of HIV-1 reverse transcriptase was reduced in the presence of the trypsin inhibitor. The trypsin inhibitor exerted antifungal activity toward Physalospora piricola but not Mycosphaerella arachidicola, Botrytis cinerea, Fusarium oxysporum or Coprinus comatus.
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PMID:A homodimeric sporamin-type trypsin inhibitor with antiproliferative, HIV reverse transcriptase-inhibitory and antifungal activities from wampee (Clausena lansium) seeds. 1267 22

Chicken ovoinhibitor cDNA was prepared by reverse transcriptase-polymerase chain reaction (RT-PCR) using chicken oviduct mRNA. The ovoinhibitor cDNA was successfully cloned downstream from the AOXI promoter of pPICZalphaA plasmid vector to facilitate its expression in the methylotrophic yeast Pichia pastoris. The pPICZalphaA carrying the ovoinhibitor cDNA was integrated into the Pichia genome. The secreted recombinant ovoinhibitor was purified by ion-exchange chromatography on a DEAE sepharose column. The recombinant ovoinhibitor had a molecular mass of 49 kDa, as determined from sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and time of flight-mass spectrometry (TOF-MS) analyses. The recombinant ovoinhibitor, just as the native ovoinhibitor, showed inhibitory activity against trypsin, chymotrypsin and elastase.
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PMID:Expression and characterization of chicken ovoinhibitor in Pichia pastoris. 1460 95

We have identified an alternatively spliced form of synaptotagmin I in Aplysia neurons. This isoform, synaptotagmin I C2B-beta, is generated by alternative exon usage in the C2B domain leading to nine amino acid changes in the C2B sequence from the previously characterized synaptotagmin I, now designated as synaptotagmin I C2B-alpha. Quantitative reverse transcriptase-polymerase chain reaction demonstrated that approximately 25% of mRNA encoding synaptotagmin I contained the C2B-beta exon in the nervous system. Synaptotagmin I C2B-beta showed greater resistance to digestion by chymotrypsin in the absence of calcium than did synaptotagmin I C2B-alpha, although both isoforms required the same amount of calcium to resist chymotrypsin digestion. The source of these changes in C2B properties was mapped to a single amino acid (threonine 358). We have also cloned SNAP 25 in Aplysia and show that it binds synaptotagmin I C2B-beta with a higher affinity than synaptotagmin I C2B-alpha. These results suggest that this splicing alters biochemical properties of the C2B domain, affecting a number of its important known interactions.
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PMID:Identification and characterization of a novel C2B splice variant of synaptotagmin I. 1505 79

Four full-length complementary DNAs of Kazal-Type serine proteinase inhibitors (SPIs) were identified from hemocyte cDNA libraries of the black tiger shrimp Penaeus monodon and recognized as having 4 (SPIPm1) and 5 (SPIPm2, SPIPm3, and SPIPm4) Kazal domains. SPIPm2 encoding a complete 5-Kazal-domain inhibitor was expressed in the Escherichia coli system. Inhibitory activity of crude proteins against various serine proteases was tested using SPI activity gelatin with sodium dodecylsulfate polyacrylamide gel electrophoresis and inhibitory spectrum assays. A 32-kDa recombinant protein (rSPIPm2) showed inhibitory activity against trypsin, chymotrypsin, and subtilisin, but not elastase. Concordantly, inhibitory spectrum assays showed that crude rSPIPm2 strongly inhibited trypsin (89%) and chymotrypsin (70%), but less effectively inhibited subtilisin (8%), and did not inhibit elastase activity. Northern blot analysis of hemocyte total RNA showed 2 SPI transcripts of 1.6 and 1.7 kb in size. Tissue-specific expression using reverse transcriptase polymerase chain reaction suggests that SPIPm2 is exclusively expressed in hemocytes of P. monodon.
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PMID:Recombinant expression and characterization of five-domain Kazal-type serine proteinase inhibitor of black tiger shrimp (Penaeus monodon). 1575 78

In the course of a large scale analysis of late-expressed genes in the human epidermis, we identified a new member of the alpha(2)-macroglobulin (alpha2M) protease inhibitor family, A2ML1 (for alpha(2)-macroglobulin-like 1). Like A2M and PZP, A2ML1 is located on chromosome 12p13.31. A2ML1 encodes a protein of 1454 amino acids, which fits the characteristics of alpha2Ms: 1) strong conservation in amino acid sequence including most of cysteine positions with alpha2M; 2) a putative central bait domain; 3) a typical thiol ester sequence. Northern blot and reverse transcriptase-PCR studies revealed a single 5-kb A2ML1 mRNA, mainly in the epidermis granular keratinocytes. A2ML1 is also transcribed in placenta, thymus, and testis. By Western blot analysis, alpha2ML1 is detected as a monomeric, approximately 180-kDa protein in human epidermis. In vitro keratinocyte differentiation is associated with increased expression levels. By immunohistochemistry, alpha2ML1 was detected within keratinosomes in the granular layer of the epidermis, and as a secreted product in the extracellular space between the uppermost granular layer and the cornified layer. Recombinant alpha2ML1 displayed inhibitory activity toward chymotrypsin, papain, thermolysin, subtilisin A, and to a lesser extent, elastase but not trypsin. Incubation with chymotrypsin and the chymotrypsin-like kallikrein 7 protease indicated that alpha2ML1 binds covalently to these proteases, a feature shared with other members of the family. Therefore, alpha2ML1 is the first alpha2M family member detected in the epidermis. It may play an important role during desquamation by inhibiting extracellular proteases.
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PMID:A novel protease inhibitor of the alpha2-macroglobulin family expressed in the human epidermis. 1629 98

Considering possible tumorigenic activity of cyclooxygenase (COX) isozymes in myeloma, we examined expression levels of COX-1 and -2 in seven human myeloma cell lines (ARH-77, IM-9, RPMI-8226, HPC, HS-Sultan, TSPC-1, and U-266). As analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR), all the cell lines constitutively expressed COX-1, while COX-2 levels markedly varied among different cell lines. Induction of COX-2 by phorbol ester was observed in RPMI-8226 and HPC cells. In contrast, COX-2 was constitutively expressed in ARH-77 and IM-9 cells. Moreover, the high expression level of COX-2 protein in ARH-77 cells was verified by Western blotting. Intact cells of ARH-77 converted 14C-labeled arachidonic acid to prostaglandin E2, F2alpha, and D2, and this activity was dose-dependently inhibited by selective COX-2 inhibitors (SC-58125 and NS-398), a non-selective COX inhibitor (indomethacin), and relatively high concentrations of a selective COX-1 inhibitor (SC-560). These COX inhibitors also suppressed the proliferation of ARH-77 cells, but significant suppression was seen only at 100 microM, a much higher concentration than those sufficient for the COX inhibition. Moreover, proliferation of the myeloma cells lacking COX-2 was also suppressed by 100 microM of SC-58125. These results suggested that the anti-proliferative effect of the COX inhibitors is independent of the inhibition of COX-2.
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PMID:Cyclooxygenase isozymes are expressed in human myeloma cells but not involved in anti-proliferative effect of cyclooxygenase inhibitors. 1638 88

Proteolytic activity of polyclonal IgG antibodies (Abs) from the blood of AIDS patients was analyzed for the first time. These Abs were shown to display higher activity in hydrolysis of beta-casein than in hydrolysis of human immunodeficiency virus (HIV)-1 reverse transcriptase (RT) or human serum albumin (HSA). Several abzymatic criteria were applied and it was shown that RT, HSA, and beta-casein hydrolyzing activities are an intrinsic property of polyclonal Abs from AIDS patients. Casein-hydrolyzing Abs were detected in the blood serum for 95% of AIDS patients, and it was shown that they possess serine protease-like catalytic activity. The substrate specificities of polyclonal Ab proteases and typical human proteases are different. Depending on the patient, the IgGs exhibit various pH optima of proteolytic activity. The products of casein hydrolysis by Ab proteases were different from those in the case of trypsin, chymotrypsin, and proteinase K.
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PMID:Proteolytic activity of IgG antibodies from blood of acquired immunodeficiency syndrome patients. 1654 61

A Bowman-Birk type trypsin-chymotrypsin inhibitor was isolated from seeds of the legume green lentil (Lens culinaris) by means of affinity chromatography on Affi-gel blue gel, ion exchange chromatography on Q-Sepharose, ion exchange chromatography by fast protein liquid chromatography (FPLC) on Mono Q and Mono S, and gel filtration by FPLC on Superdex 75. The trypsin-chymotrypsin inhibitor was bound on the first three types of chromatographic media. It appeared as a single 16-kDa peak in gel filtration and a single 16-kDa band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The trypsin inhibitory activity of the inhibitor was sensitive to the reducing agent dithiothreitol. It was completely abrogated after treatment with 10 mM dithiothreitol for 20 minutes. The protease inhibitor did not exert any inhibitory effect on hepatoma (Hep G2) and breast cancer (MCF 7) cell lines. There was no suppressive action on several fungal species including Botrytis cinerea, Fusarium oxysporum and Mycosphaerella arachidicola. It slightly inhibited the activity of HIV-1 reverse transcriptase, with an IC50 of 30 mM.
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PMID:Isolation and characterization of a trypsin-chymotrypsin inhibitor from the seeds of green lentil (Lens culinaris). 1804 26

A trypsin inhibitor with a molecular mass of about 19 kDa was isolated from seeds of Chinese black soybean Glycine max cv. "Small Glossy Black". It was isolated using a protocol that comprised ion exchange chromatography on Q-Sepharose, SP-Sepharose and DEAE-cellulose. It was adsorbed on all three ion exchangers. It inhibited trypsin with an IC(50) of 19 microM and chymotrypsin with an IC(50) of 14.3 microM. Its trypsin inhibitory activity was stable in the pH range pH 3-pH 13 and in the temperature range 0 degree C-60 degrees C. The trypsin inhibitor was inhibited by dithiothreitol (from 5 to 25 mM) in a dose-dependent manner. It exhibited an N-terminal sequence highly homologous to Kunitz-type trypsin inhibitors. It inhibited HIV-1 reverse transcriptase with an IC(50) of 0.16 microM, and suppressed proliferation of MCF-7 breast cancer cells with an IC(50) of 4.3 microM and HepG2 hepatoma cells with an IC(50) higher than 25 microM. The trypsin inhibitor lacked antifungal activity and mitogenic activity towards mouse splenocytes.
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PMID:A trypsin-chymotrypsin inhibitor with antiproliferative activity from small glossy black soybeans. 1923 24

Three trypsin-chymotrypsin inhibitors were isolated from seeds of the black gram (Vigna mungo) with a procedure that entailed cation exchange chromatography on SP-Sepharose, anion exchange chromatography on Q-Sepharose, ion exchange chromatography by fast protein liquid chromatography (FPLC) on Mono Q and Mono S, and gel filtration by FPLC on Superdex 75. Two of the trypsin-chymotrypsin inhibitors were adsorbed on the first four types of chromatographic media. All three inhibitors have a molecular mass of 16 kDa as judged by gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The trypsin inhibitory activity of the inhibitors was attenuated in the presence of the reducing agent dithiothreitol. The remaining inhibitor was unadsorbed on SP-Sepharose but adsorbed on Q-Sepharose, Mono Q and Mono S. The protease inhibitors did not exert any inhibitory effect on hepatoma (Hep G2) and breast cancer (MCF 7) cells or antifungal action toward Botrytis cinerea, Fusarium oxysporum and Mycosphaerella arachidicola. Two of the inhibitors slightly inhibited the activity of HIV-1 reverse transcriptase, with an IC50 in the millimolar range.
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PMID:Trypsin-chymotrypsin inhibitors from Vigna mungo seeds. 1927 41


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