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)

In order to explore the possibility of supplanting the requirement of a 5'-triphosphate moiety for the activation of the 2-5A-dependent endonuclease (RNase L) of mouse L-cells, two new tetrameric analogues of 2-5A were synthesized. The first tetramer, obtained by both a modified prebiotic synthetic approach as well as a phosphite triester solid phase oligonucleotide synthesis method, was p5'A2'p5'A2'p5'(br8A)2'p5'(br8A). The second oligonucleotide was derived from the former by a sequence involving periodate oxidation, reaction with n-hexylamine, and cyanoborohydride reduction, resulting in conversion of the 2'-terminal adenosine residue to 9-(3'-aza-4'-hexyl-1',2',3',4'-tetradeoxyhexopyranos-1(1)-yl)-8-++ +bromoadenine. Both of these oligomers, bearing only 5'-monophosphate groups, were found to be as potent as 2-5A itself as activators of the RNase L of mouse L-cells.
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PMID:A new and potent 2-5A analogue which does not require a 5'-polyphosphate to activate mouse L-cell RNase L. 141 9

An analog of the alpha-human atrial natriuretic polypeptide (alpha-hANP) gene, articulated with a peptidase inhibitor SQ20881 at its N-terminal and two prolines at the C-terminal was expressed in E. coli by cloning the reconstituted plasmid pRHL-1 in vivo. This gene analog, RH-1, comprising 154 base pairs in total, was designed to contain an equivalent of the alpha-hANP gene, capping the peptidase inhibitor SQ20881 at its 5' end with a glutamic acid codon GAA to facilitate enzymatic cleavage of the expressed end product by endoproteinase Glu-C, wedging in two proline codons CCG & CCG before the double terminal codons TGA TAG at the 3' end to retard hydrolysis of the expressed product by exopeptidase, and adding 3 restriction sites to both ends. Synthesis of the RH-1 gene was effected enzymatically by joining in predicted order the ten segments of oligodeoxynucleotides which had been chemically synthesized by the solid-phase phosphite-triester method. The synthetic gene was cloned into vector M13mp18. Phage bearing the gene analog was identified by dot blotting and restriction endonuclease mapping. Nucleotide sequence of the gene was determined by the dideoxynucleotide chain termination method.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[A study of protein engineering for human cardionatrin. I. Synthesis, cloning and expression of a gene analog of human atrial natriuretic polypeptide in E. coli]. 214 Jul 17

Protected deoxynucleoside 3'-O-ethyl-N,N-diisopropylphosphoramidite reagents were prepared for use in the automated synthesis of ethyl phosphotriester (Et) modified oligonucleotides. The title diastereomers were separated by reversed-phase HPLC, and chirality at phosphorus was assigned by an improved configurational correlation scheme that was verified by NMR spectroscopic studies (accompanying paper, Part VI). This generally applicable correlation scheme involved enzymatic digestions of each diastereomer to give the corresponding diastereomer of d[A(Et)T]; phosphite triester sulfurization to obtain diastereomeric O-ethyl phosphorothioates, d[AS(Et)T], which were separated by HPLC for stereoretentive oxidation with H2O2 to give d[A(Et)T], and stereoretentive de-ethylation with PhSH-Et3N to give diastereomeric phosphorothioates, d[AST], whose configurations at phosphorus had been assigned previously. Neither the Rp-Rp nor Sp-Sp duplex, (d[GGAA(Et)TTCC])2, was cleaved by EcoRI endonuclease under conditions that led to cleavage of both the unmodified duplex, [d(GGAATTCC)]2, and the mixture of diastereomeric phosphorothioate-modified duplexes, [d(GGAASTTCC)]2. Cleavage of the latter substrates was Sp-selective.
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PMID:Alkyl phosphotriester modified oligodeoxyribonucleotides. V. Synthesis and absolute configuration of Rp and Sp diastereomers of an ethyl phosphotriester (Et) modified EcoRI recognition sequence, d[GGAA(Et)TTCC]. A synthetic approach to regio- and stereospecific ethylation-interference studies. 302 May 14

The synthesis and characterization of an octanucleotide, d(GGsAATTCC), containing the recognition sequence of the EcoRI restriction endonuclease with a phosphorothioate internucleotidic linkage at the cleavage site are described. Two approaches for the synthesis of the RP and SP diastereomers of this octamer by the phosphite method are presented. The first consists of the addition of sulfur instead of H2O to the phosphite at the appropriate position during chain elongation. This method results in a mixture of diastereomers that can be separated by high-performance liquid chromatography after 5'-terminal phosphorylation. The second uses the presynthesized and diastereomerically pure dinucleoside phosphorothioate d[Gp(S)A] for the addition to the growing oligonucleotide chain as a block. The products are characterized by digestion with nuclease P1, fast atom bombardment mass spectrometry, 31P NMR spectroscopy, and conversion to d(GGAATTCC) by desulfurization with iodine. Only the RP diastereomers of d(GGsAATTCC) and its 5'-phosphorylated derivative are cleaved by EcoRI endonuclease. The rate of hydrolysis is slower than that of the unmodified octamer. The phosphorothioate octamer will be useful for the determination of the stereochemical course of the EcoRI-catalyzed reaction.
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PMID:Synthesis and characterization of an octanucleotide containing the EcoRI recognition sequence with a phosphorothioate group at the cleavage site. 608 94