Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The cDNA thymosin beta(4) was synthesized by combining of chemical and enzymatic methods. First, two complement fragments of thymosin beta(4) cDNA were synthesized by DNA synthesizer, and then denatured, annealed and extended by DNA polymerase. This fragment of thymosin beta(4) was then inserted into the EcoRV and HindIII restriction endonuclease site of an expression plasmid pLDH4 (a kind of E.coli plasmid) by blunt and cohesive ligations. Finally, the recombinant plasmid which expressed thymosin beta(4) was screened by digestion and DNA sequencing. This recombinant plasmid highly expressed the thymosin beta(4), which accounted for 30% of total bacteria proteins. By salting out and chromatography, a 95% purity of recombinant thymosin beta(4) was obtained. Biological assay indicated that the recombinant thymosin beta(4) could induce lymphocyte proliferation and differentiation.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 2002 Jul
PMID:Cloning expression in E.coli and biological activity of human thymosin beta(4). 1209 76

The effect of high hydrostatic pressure on the activities of type II restriction enzymes HindIII and XbaI in digesting plasmid pSPORT1 was studied. The endonuclease activity of HindIII and XbaI at 37 degrees were gradually inhibited by increasing pressure and completely inhibited at 200 and 180 MPa, respectively. No obvious irreversible effect was observed for HindIII after suffering high pressure, while a considerable irreversible inactivation was observed for XbaI. The standard molar volume changes for HindIII and XbaI estimated from the inhibition of endonuclease activity at different pressures were 213 and 103 ml/mol, respectively. It was also concluded that pressurization did not change the substrate sequence specificity of both HindIII and XbaI.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 1999
PMID:Effect of High Hydrostatic Pressure on Activity of Restriction Endonucleases. 1211 64

Arginyl-tRNA synthetase (ArgRS) from E. coli was overproduced from transformant containing the gene encoding this enzyme (argS) by 550 fold higher than that from host cell. By site-directed mutagenesis the cleavage site for NcoI restriction endonuclease was introduced into the start codon of argS. The mutant gene was recombinated with plasmid pTrc99B under IPTG control. In the transformant containing the recombinated plasmid, argS can overexpressed 2 000 times higher than that in host cell. Through one step DEAE-Sepharose column chromatography, ArgRS was purified to be one band by SDS-PAGE and its specific activity was 15 000 u/mg, similar to reported values. The mutant ArgRS2ND which had the second residue asparagine replaced by aspartic acid showed no change of activity, kinetic constants nor the thermal and denaturational stabilities.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 1998
PMID:Study on the Overexpression of the Gene Encoding Arginyl-tRNA Synthetase under Induction. 1217 53

Escherichia coli HX88108, which is resistant to cefoperazone(CPZ), was isolated from a severely infected patient. We studied genetical basis of beta-lactamase produced in E. coli HX88108 by pFL25, one of the recombinant plasmid of pFC. Largescale pFL25 plasmid was extracted, purified, and cleaved with restriction endonuclease EcoR I, Sal I, Pvu I, then subcloned into vector pUC19 as 1.9 kb, 0.9 kb, 0.65 kb fragments respectively. Recomminant plasmids were selected by alpha-complementation and determined by restriction endonuclease analysis. DNA sequencing was performed by the dideoxy polymerase chain termination method. Partial nucleotide sequence(1-78 nucleotide position) of the gene was found to be highly homologous (97%) with the gene coding for TEM-52 extended spectrum beta-lactamase of K. pneumonise, suggesting that the beta-lactamase coded by the cefoperazone resistant gene might be derived from TEM-type beta-lactamase.
Hua Xi Yi Ke Da Xue Xue Bao 1999 Sep
PMID:[Sub-cloning and preliminary sequence analysis of the gene encoding of a cefoperazone hydrolyzing beta-lactamase isolated from Escherichia coli]. 1221 72

We have generated and purified a new recombinant baculovirus with expanded host range. AcNPV DNA and BamHI-digested BmNPV DNA were co-transfected into Spodoptera frugiperda SF21 cells. Progeny viruses were used to infect BmN cells, which are normally resistant to AcNPV infection, in order to screen for recombinant viruses with cross-infectivity. A recombinant virus was isolated by plaque purification and analyzed. This isolate was able to infect, replicate and produce polyhedrin in both the SF21 and BmN cells. DNA restriction endonuclease analysis showed that it was a hybrid (HyNPV) of AcNPV and BmNPV. Co-transfection of this HyNPV virus with a transfer vector containing a ligninase H8 gene insert into SF21 cells yielded a recombinant baculovirus expressing the ligninase. When this recombinant baculovirus was used to infect either SF21 or BmN cells, ligninase proteins could be found in the lysed cells as well as in the cell culture media. We have thus demonstrated that this hybrid virus can be utilized in the generation of recombinant baculovirus expressing foreign proteins in two host cells which normally can not be infected by AcNPV nor BmNPV.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 1997
PMID:Expression of a Ligninase by a New Hybrid Baculovirus with Expanded Host Range. 1221 9

In order to construct a genomic bivalent oral vaccine of Leishmania donovani and Vibrio cholerae, we amplified a 1.3 kb DNA fragment from 7 strains of Vibrio cholerae with primers P1 and P2. Restriction endonuclease analysis of PCR amplified products from 9 strains of Vibrio cholerae was performed by digestion with EcoR I. The results revealed an EcoR I site in the central part of toxR gene. The entire toxR gene of Vibrio cholerae Non-CT strain 7743 was amplified by PCR with primers P1 and P2, digested with endonucleases BamH I and Hind III, then was orientationally cloned into plasmid pAT153. The restriction endonuclease analysis demonstrates that the recombinant plasmid ptR4 contains a 1.3 kb toxR gene fragment.
Hua Xi Yi Ke Da Xue Xue Bao 2000 Mar
PMID:[PCR amplification and cloning of virulence expression regulatory gene toxR of Vibrio cholerae]. 1250 5

The purpose of this paper is to investigate the antitumor effects of cytosine deaminase/5-fluorocytosine (CD/5-FC) suicide gene therapy system on human malignant glioma cells in vitro. The pCMVCD plasmid was constructed through the CD gene insertion in the multicloning site of eukaryotic expression vector pcDNA3.0, and confirmed by restriction endonuclease digestion/gene sequencing. The construct was subsequently transfected into the U251 human malignant glioma cells by using LipofectAMINE2000-mediated method. Resistant clones (named U251/CD cells) were isolated by screening with G418 presence. U251/CD cells were incubated with 5-FC in different concentrations to determine viability ratios (or cytotoxicity assay), measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The concentrations of 5-fluorouracil (5-FU) in the media were measured by high-performance liquid chromatography (HPLC) detector. Our results suggested that the untreated U251 cells were insensitive to 5-FC, with the IC(50) about 6500 micromol/L. After transfection, the IC(50) was dramatically reduced to about 10 micromol/L. Therefore, gene transfection made G418-resistant clones (U251/CD cells) be highly sensitive to 5-FC. HPLC analysis showed that 5-FU was detected in U251/CD cell medium. Study on U251 cells genetically modified by CD gene in vitro will play an essential role in glioma gene therapy in vivo. In conclusion, our results indicated that the CD/5-FC system was feasible to treat glioma.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 2003 May
PMID:Effects of CD/5-FC suicide gene therapy system on human malignant glioma cells in vitro. 1276 3

DNA sequence of a plasmid pEIB1 associated with virulence from the marine fish pathogen Vibrio anguillarum was determined using the methods of restriction endonuclease digestion, subcloning, and primer walking. The whole length of obtained pEIB1 DNA sequence was 66 164 bp, and the overall G+C content of DNA sequence is 42.7%. This sequence encodes 44 open reading frames containing the genes of DNA replication, biosynthesis and regulation of the siderophore anguibactin and transport of ferric-anguibactin complexes.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 2003 Oct
PMID:DNA sequencing of a plasmid with virulence from marine fish pathogen Vibrio anguillarum. 1451 17


<< Previous 1 2