Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

DNA polymerase was purified from a cloned isolate of Moloney murine leukemia virus (M-MuLV). Purified M-MuLV DNA polymerase, upon analysis by polyacrylamide gel electrophoresis, showed one major polypeptide of mol wt 80,000. Estimation of molecular weight from the sedimentation rate of the purifed enzyme in a glycerol gradient was consistent with a structure containing one polypeptide. M-MuLV DNA polymerase could transcribe ribopolymers, deoxyribopolymers, and heteropolymers as efficiently as did purified DNA polymerase from avian myeloblastosis virus (AMV). M-MuLV DNA polymerase, however, transcribed native 70S viral RNA less efficiently than did AMV DNA polymerase. Addition of oligo(dT) enhanced five to tenfold the transcription of 70S viral RNA by M-MuLV DNA polymerase. Purified enzyme also exhibited nuclease activity (RNase H) that selectively degraded the RNA moiety of the RNA-DNA hybrid. It did not degrade single-stranded RNA, single-stranded DNA, double-stranded RNA, and double-stranded DNA. M-MuLV DNA polymerase-associated RNase H acted as a random exonuclease. When [3-H]poly(A)-poly(dT) was used as a substrate, the size of the M-MuLV DNA polymerase-associated RHase H digested product was larger than the size of the digestion products by AMV DNA polymerase. The oligonucleotide digestion products could be further digested to 5'-AMP by snake venom phosphodiesterase, indicating that the products were terminated by 3'-OH groups. Alkaline hydrolysis of the oligonucleotide digestion products generated pAp, suggesting that M-MuLV DNA polymerase-associated RNase H cleaves at the 3' side of the 3',5'-phosphodiester bond. The ratios of the rates of DNA polymerase activity and RNase H activity were not significantly different in the murine and avian enzymes.
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PMID:Studies on reverse transcriptase of RNA tumor viruses III. Properties of purified Moloney murine leukemia virus DNA polymerase and associated RNase H. 4 25

9-[5'-(2-Oxo-1,3,2-oxazaphosphorinan-2-yl)-beta-D-arabinosyl]adeni ne (1c) and 9-[5'-(2-oxo-1,3,2-dioxaphosphorinan-2-yl)-beta-D-arabinosyl]adeni ne (1d) were synthesized by reaction of 9-[beta-D-arabinofuranosyl]adenine with phosphoryl chloride with 1-amino-3-propanol and 1,3-propanediol, respectively. 1c consisted of a mixture of diastereomers, while 1d was enantiomerically homogeneous. The structures of these compounds were established by spectral (1H NMR, MS, UV) and elemental analyses. Both 1c and 1d were resistant to degradation by 5'-nucleotidase, alkaline phosphatase, venom phosphodiesterase, crude snake venom, adenosine deaminase, and adenylate deaminase. Neither compound was significantly biotransformed by mouse hepatic microsomal preparations in the presence of an NADPH-generating system. Compound 1c was marginally effective at prolonging the life span of mice bearing P-388 leukemia; compound 1d, however, was inactive.
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PMID:Synthesis and biological evaluation of 9-[5'-(2-oxo-1,3,2-oxazaphosphorinan-2-yl)-beta-D-arabinosyl]ade nine and 9-[5'-(2-oxo-1,3,2-dioxaphosphorinan-2-yl)-beta-D-arabinosyl]ade nine: potential neutral precursors of 9-[beta-D-arabinofuranosyl]adenine 5'-monophosphate. 241 27

The chemical synthesis of thiazole-4-carboxamide adenine dinucleotide (TAD), previously identified as the active anabolite of the oncolytic 2-beta-D-ribofuranosylthiazole-4-carboxamide (TR), has been achieved by three different approaches: (1) incubation of adenosine 5'-monophosphate (AMP) and 2-beta-D-ribofuranosylthiazole-4-carboxamide 5'-monophosphate (TRMP) with excess DCC in aqueous pyridine, (2) reaction of adenosine 5'-phosphoromorpholidate with TRMP in pyridine, and (3) reaction of adenosine-5'-phosphoric di-n-butylphosphinothioic anhydride with TRMP in the presence of AgNO3. While the first approach produced only traces of TAD, the last two afforded 31 and 16% yields, respectively, of isolated TAD. The synthetic material was indistinguishable from biosynthesized TAD as judged by its HPLC behavior, NMR, UV and mass spectra, enzymatic resistance to alkaline phosphatase and susceptibility to venom phosphodiesterase, IMP dehydrogenase inhibitory activity, and cytotoxicity. TAD and TR were equally effective against murine P388 leukemia when employed at equimolar doses.
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PMID:Synthesis of thiazole-4-carboxamide adenine dinucleotide. A powerful inhibitor of IMP dehydrogenase. 613 56

Following the parenteral administration of tiazofurin, 2-beta D-ribofuranosylthiazole-4-carboxamide (thiazole nucleoside, TR), a potent but reversible inhibitor of IMP dehydrogenase is generated in subcutaneous nodules of the P388 leukemia. The compound responsible for this effect has been isolated from homogenates of the tumor by ion-exchange HPLC, and its presence monitored by enzyme-inhibition assay. The inhibitor has also been prepared by incubation of tiazofurin with P388 cells in culture. Chromatographically, the inhibitory principle exhibits a moderately strong set negative charge at pH 3, and elutes in the general vicinity of the nucleoside-5'-diphosphates; its absorption maximum in aqueous solution (pH 7) lies at 252 nm. Exposure of the molecule to snake-venom phosphodiesterase or to nucleotide pyrophosphatase destroys its inhibitory potency, whereas other phosphodiesterases are either less effective or inert. Since these results suggested that the anabolite might be a dinucleotide with a phosphodiester linkage of the kind found in NAD, attempts were made to synthesize such an analogue from the 5'-monophosphate of thiazole nucleoside and ATP-Mg2+, using a purified preparation of NAD pyrophosphorylase; modest yields were obtained of a compound with chromatographic, spectral and enzyme-inhibitory properties identical to those of the material isolated from P388 tumor nodules. This enzyme-synthesized material was radioactive when [3H]ATP was used as cosubstrate, and yielded both AMP and thiazole nucleoside-5'-monophosphate on treatment with phosphodiesterase. It resisted attack by NAD glycohydrolase. An apparently identical dinucleotide was also synthesized chemically by means of the Khorana condensation. Mass spectral analysis and nuclear magnetic resonance studies with homogeneous preparations of both the enzymically and chemically synthesized compound were compatible with its being a dinucleotide in which the nicotinamide of NAD has been replaced by thiazole-4-carboxamide. Versus IMP dehydrogenase, the dinucleotide exhibited a K1 of approximately 2 X 10(-7) M and was non-competitive with NAD as the variable substrate. Other NAD utilizing enzymes, including representative dehydrogenases and poly ADP ribose polymerase, were, by comparison to mammalian IMPD, resistant to inhibition by TAD. The properties of this novel dinucleotide are compared and contrasted with those of analogs of NAD containing modifications in the pyridine, adenine or ribofuranose rings, as well as in the pyrophosphate bridge.
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PMID:Studies on the mechanism of action of tiazofurin metabolism to an analog of NAD with potent IMP dehydrogenase-inhibitory activity. 615 29

5-Fluoro-5'-(2-oxo-1,3,2-oxazaphosphorinan-2-yl)-2'-deoxyuridine (1a) and 5-fluoro-5'-(2-oxo-1,3,2-dioxaphosphorinan-2-yl)-2'-deoxyuridine (1b) were prepared by reaction of 5-fluoro-2'-deoxyuridine (7a) and phosphoryl chloride with 3-amino-1-propanol and 1,3-propanediol, respectively. The thymidine analogues, 1c and 1d, were prepared similarly from thymidine. Compound 1b was synthesized in better yield from 13a and trimethylene phosphate with triphenylphosphine/diethyl azodicarboxylate as a condensing agent. Compounds 1a-d were resistant to degradation by 5'-nucleotidase, alkaline phosphatase, venom phosphodiesterase, and crude snake venom. None of these compounds were significantly biotransformed when incubated with mouse hepatic microsomal preparations in the presence of an NADPH-generating system. When administered intraperitoneally (ip) for 5 consecutive days, 1a was nearly as effective as 5-fluorouracil at prolonging the life spans of BDF1 mice implanted intraperitoneally with leukemia P-388. However, much larger dosages of 1a were required for optimal activity. Compound 1b administered similarly was only marginally effective. Neither 1a nor 1b was active against a P-388 mutant resistant to 5-fluorouracil.
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PMID:Synthesis and biological evaluation of neutral derivatives of 5-fluoro-2'-deoxyuridine 5'-phosphate. 630 57