| http://purl.uniprot.org/citations/2172926 | http://www.w3.org/1999/02/22-rdf-syntax-ns#type | http://purl.uniprot.org/core/Journal_Citation |
| http://purl.uniprot.org/citations/2172926 | http://www.w3.org/2000/01/rdf-schema#comment | "Synthesis of Sp and Rp diastereomers of Ap4A alpha S has been characterized in two enzymatic systems, the lysyl-tRNA synthetase from Escherichia coli and the Ap4A alpha, beta-phosphorylase from Saccharomyces cerevisiae. The synthetase was able to use both (Sp)ATP alpha S and (Rp)ATP alpha S as acceptors of adenylate thus yielding corresponding monothioanalogues of Ap4A,(Sp) Ap4A alpha S and (Rp)Ap4A alpha S. No dithiophosphate analogue was formed. Relative synthetase velocities of the formation of Ap4A,(Sp) Ap4A alpha S and (Rp)Ap4A alpha S were 1:0.38:0.15, and the computed Km values for (Sp)ATP alpha S and (Rp)ATP alpha S were 0.48 and 1.34 mM, respectively. The yeast Ap4A phosphorylase synthesized (Sp)Ap4A alpha S and (Rp)Ap4A alpha S using adenosine 5'-phosphosulfate (APS) as source of adenylate. The adenylate was accepted by corresponding thioanalogues of ATP. In that system, relative velocities of Ap4A, (Sp)Ap4A alpha S and (Rp)Ap4A alpha S formation were 1:0.15:0.60. The two isomeric phosphorothioate analogues of Ap4A were tested as substrates for the following specific Ap4A-degrading enzymes: (asymmetrical) Ap4A hydrolase (EC 3.6.1.17) from yellow lupin (Lupinus luteus) seeds hydrolyzed each of the analogues to AMP and the corresponding isomer of ATP alpha S; (symmetrical) Ap4A hydrolase (EC 3.6.1.41) from E. coli produced ADP and the corresponding diastereomer of ADP alpha S; and Ap4A phosphorylase (EC 2.7.7.53) from S. cerevisiae cleaved the Rp isomer only at the unmodified end yielding ADP and (Rp)ATP alpha S whereas the Sp isomer was degraded non-specifically yielding a mixture of ADP, (Sp)ADP alpha S, ATP and (Sp)ATP alpha S. For all the Ap4A-degrading enzymes, the Rp isomer of Ap4A alpha S appeared to be a better substrate than its Sp counterpart; stereoselectivity of the three enzymes for the Ap4A alpha S diastereomers is 51, 6 and 2.5, respectively. Basic kinetic parameters of the degradation reactions are presented and structural requirements of the Ap4A-metabolizing enzymes with respect to the potential substrates modified at the Ap4A-P alpha are discussed."xsd:string |
| http://purl.uniprot.org/citations/2172926 | http://purl.org/dc/terms/identifier | "doi:10.1093/nar/18.20.6083"xsd:string |
| http://purl.uniprot.org/citations/2172926 | http://purl.uniprot.org/core/author | "Guranowski A."xsd:string |
| http://purl.uniprot.org/citations/2172926 | http://purl.uniprot.org/core/author | "Lazewska D."xsd:string |
| http://purl.uniprot.org/citations/2172926 | http://purl.uniprot.org/core/date | "1990"xsd:gYear |
| http://purl.uniprot.org/citations/2172926 | http://purl.uniprot.org/core/name | "Nucleic Acids Res"xsd:string |
| http://purl.uniprot.org/citations/2172926 | http://purl.uniprot.org/core/pages | "6083-6088"xsd:string |
| http://purl.uniprot.org/citations/2172926 | http://purl.uniprot.org/core/title | "P alpha-chiral phosphorothioate analogues of bis(5'-adenosyl)tetraphosphate (Ap4A); their enzymatic synthesis and degradation."xsd:string |
| http://purl.uniprot.org/citations/2172926 | http://purl.uniprot.org/core/volume | "18"xsd:string |
| http://purl.uniprot.org/citations/2172926 | http://www.w3.org/2004/02/skos/core#exactMatch | http://purl.uniprot.org/pubmed/2172926 |
| http://purl.uniprot.org/citations/2172926 | http://xmlns.com/foaf/0.1/primaryTopicOf | https://pubmed.ncbi.nlm.nih.gov/2172926 |
| http://purl.uniprot.org/uniprot/P16550#attribution-01F975343BADD1AF1E6AF85F3A33C3A9 | http://purl.uniprot.org/core/source | http://purl.uniprot.org/citations/2172926 |
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| http://purl.uniprot.org/uniprot/P16550 | http://purl.uniprot.org/core/mappedCitation | http://purl.uniprot.org/citations/2172926 |