The Enzymatic Aminohydrolysis of 4-Aminopyrimidine Deoxyribonucleotides
1962; Elsevier BV; Volume: 237; Issue: 12 Linguagem: Inglês
10.1016/s0021-9258(19)84518-0
ISSN1083-351X
AutoresEduardo Scarano, Luisa Bonaduce, B. De Petrocellis,
Tópico(s)Chemical Synthesis and Analysis
ResumoPrevious papers described the finding that extracts of tissues from warm-blooded animals catalyze specifically the aminohydrolysis of 2'-deoxyribosyl cytosine 5'-phosphate to 2'-deoxyribosyl uracil 5'-phosphate and of 2'-deoxyribosyl 5-methylcytosine 5'-phosphate to 2'-deoxyribosyl thymine 5'-phosphate (1,(3)(4)(5)(6).The aminohydrolysis of dCMP by tissue extracts from warm-blooded animals has been reported also by Maley and Maley (7, 8) and by Fiala et al. (9, 10).A highly purified enzyme preparation that catalyzes the aminohydrolysis of dCMP to dUMP, CHa-dCMP to dTMP, and CH2-OH-dCMP to CHZOH-dUMP was obtained from sea urchin eggs (1).Inasmuch as extensive purification failed to resolve separate aminohydrolases, it seemed likely that one enzyme with 2'-deoxyribosyl 4-aminopyrimidone-2,5'-phosphate aminohydrolase activity accounts for the aminohydrolysis of the three deoxyribonucleotides.The enzyme has been referred to as 2'-deoxyribosyl 4-aminopyrimidone-2,5'-phosphate aminohydrolase.Since dPAase* seems to be involved in the metabolic pathway to dTMP synthesis in eggs and in embryos of sea urchins (1), it is of interest to investigate whether or not the enzyme is present also in tissues of warm-blooded animals.The present paper deals mainly with the preparation of highly purified dPAase from monkey liver and with some properties of the purified enzyme.It is shown also that the purification procedure worked out with monkey liver also permits the preparation of highly purified dPAase from rabbit liver.Finally evi-
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