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)

A new cationic polymer, N,N-diethylethylenediamine-polyurethane (DEDA-PU), bearing tertiary amines in the backbone and side chains, was synthesized and used as a nonviral vector for gene delivery. The DEDA-PU readily self-assembled with the plasmid DNA (pCMV-betagal) in water and buffer at physiological pH, as determined by agarose gel retardation, dynamic light scattering, zeta potential, atomic force microscopy (AFM), and restriction endonuclease protection assays. The results revealed that DEDA-PU was able to bind with plasmid DNA, yielding positively charged complexes with a size around 100 nm at a DEDA-PU/DNA ratio of 50/1 (w/w). The DEDA-PU/DNA complexes were able to transfect HEK 293 cells in vitro with an efficiency comparable to a well-known gene carrier [poly(2-dimethylaminoethyl methacrylate), PDMAEMA]. The cytotoxicity of DEDA-PU was substantially lower than PDMAEMA. The degradation studies indicated that DEDA-PU degrades hydrolytically in 20 mM HEPES buffer at pH 7.4 with a half-life of approximately 60 h. This study shows that DEDA-PU holds promise as biodegradable polycations for gene delivery and is interesting candidate for further study.
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PMID:Synthesis of novel biodegradable cationic polymer: N,N-diethylethylenediamine polyurethane as a gene carrier. 1536 Mar 7

Type I restriction enzymes are multimeric proteins that consist of three subunits. The HsdS and HsdM subunits form a complex protein that shows methyltransferase activity, while the HsdR subunit functions as an endonuclease as well as as a translocase. Of these three subunits, no structural information on the HsdR subunit is yet available. The putative HsdR gene from Vibrio vulnificus YJ016 (HsdR_Vv) was cloned and expressed and the expressed protein HsdR_Vv was purified. HsdR_Vv was crystallized from 8%(w/v) polyethylene glycol 3350, 0.15 M ammonium chloride, 0.1 M HEPES pH 7.5 and 2 mM beta-mercaptoethanol. Diffraction data were collected to 2.60 A resolution using synchrotron radiation. The crystal belongs to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 71.01, b = 89.04, c = 113.66 A. With one HsdR_Vv molecule in the asymmetric unit, the Matthews coefficient was 2.14 A(3) Da(-1) and the solvent content was 42%.
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PMID:Crystallization and preliminary X-ray diffraction analysis of the HsdR subunit of a putative type I restriction enzyme from Vibrio vulnificus YJ016. 1893 37

Novel copper(ii) complexes bearing 2,2'-bipyridine (bpy) derivatives with adenine, thymine and uracil nucleobases [Cu(L(1))Cl(2)].2H(2)O (1), [Cu(L(2))Cl(2)] (2) and [Cu(L(3))Cl(2)].H(2)O (3) (L(1) = 5,5'-Di[N9-adenylmethyl]-2,2'-bipyridine, L(2) = 5,5'-Di[N1-thyminylmethyl]-2,2'-bipyridine and L(3) = 5,5'-Di[N1-uracilmethyl]-2,2'-bipyridine) were synthesized and characterized. Structure simulation was performed for these complexes. Circular dichroism (CD) spectra revealed the interactions between these ligands and pBR322 DNA and showed that the local DNA structure was perturbed by these ligands. Cleavage of pBR322 DNA by these complexes was carried out in 20 mM HEPES (pH 7.5) at 37 degrees C. The calculated pseudo-Michaelis-Menten kinetic parameters (k(cat)) were 14.7 +/- 0.6 and 40.4 +/- 1.3 h(-1) for and . The cleavage efficiency of was 80-fold higher than that of its simple analogue [Cu(bpy)Cl(2)] (k(cat) = 0.50 h(-1)) and very close to the catalytic rate constant of natural EcoRI endonuclease (k(cat) = 43.2 h(-1)) at similar conditions. Thus, complex might be one of the most effective artificial nucleases that could catalyze double-stranded DNA hydrolytic cleavage so far. Hydrolytic mechanisms involved in DNA cleavage were explored using radical scavengers and T4 ligase. Competitive experiments with special binding agents showed that complexes could preferentially bind to the minor groove of double-stranded DNA, suggesting specific DNA binding characteristics. Molecular docking calculations also indicated that complexes could bind to the minor groove of targeted DNA much more strongly than their simple analogues and preferentially bind at the AT region of the dodecamer. Such high DNA cleavage ability and selectivity of these copper(ii) complexes could be attributed to the synergic effects of the metal center and the pendant nucleobases.
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PMID:An effective approach to artificial nucleases using copper(II) complexes bearing nucleobases. 2014 33