[51] Cytosine and cytidine deaminase from yeast

  title={[51] Cytosine and cytidine deaminase from yeast},
  author={P. Ipata and G. Cercignani},
  journal={Methods in Enzymology},
Publisher Summary This chapter describes the purification procedure of cytosine and cytidine deaminase from yeast. The hydrolytic deamination of cytidine to uridine and of cytosine to uracil is catalyzed in yeast by two distinct enzyme proteins. Both cytosine and cytidine deaminase activities can be determined by direct spectrophotometric assay from the fall in absorbance at 286 nm following the conversion of the 4-amino to the 4-keto compounds. The pooled active fractions can be stored at -20… Expand
Cloning, overexpression, and purification of cytosine deaminase from Saccharomyces cerevisiae.
A purification protocol has been developed which permits recovery of 60% of cytosine deaminase in active form from induced cell lysates after two purification steps, which will be useful for isolating large quantities of pure enzyme which are required for the preclinical evaluation of monoclonal antibody-cytosineDeaminase conjugates in combination with 5-fluorocytosines. Expand
Crystallization and preliminary X-ray analysis of bacterial cytosine deaminase.
Selenomethionine-containing protein has been prepared and crystallized for MAD phasing and allows the formation of a cytotoxic chemotherapeutic agent from a non-cytotoxic precursor. Expand
The biosynthesis of uridine 5'-monophosphate in Giardia lamblia.
Evidence is provided that the pyrimidine nucleoside phosphorylases were a single enzyme capable of utilizing uridine, deoxyuridine and thymidine (and corresponding bases) as substrates and can be viewed as potential targets at which to direct chemotherapeutic agents. Expand
Salvage of pyrimidine nucleosides by Trichomonas vaginalis.
  • C. Wang, H. Cheng
  • Biology, Medicine
  • Molecular and biochemical parasitology
  • 1984
T. vaginalis has no appreciable dihydrofolate reductase or thymidylate synthetase; it grows normally in millimolar concentrations of methotrexate, pyrimethamine, or trimethoprim, and cannot incorporate labels from exogenous uracil or uridine into DNA, but has an enzyme thymidine phosphotransferase in the sedimentable fraction which converts thymazine to TMP. Expand
Crystal Structure of Yeast Cytosine Deaminase
The enzyme shares similar active-site architecture to cytidine deaminases and an unusually high structural homology to 5-aminoimidazole-4-carboxamide-ribonucleotide transformylase and thereby may define a new superfamily. Expand
A new thymidylate biosynthesis in Xanthomonas oryzae infected by phage Xp 12.
An enzyme 5-methyldeoxycytidylate aminohydrolase, responsible for this conversion, was detected in a cell-free system of Xp12-infected cells and seems likely that the conversion occurred at the nucleotide level of 5-methylcytosine. Expand
Purification and characterization of Aspergillus parasiticus cytosine deaminase for possible deployment in suicide gene therapy
Cytosine Deaminase from Aspergillus parasiticus was purified and characterized and can be compared with CDs from other sources that are used in suicide gene therapy. Expand
Isolation from Nocardioides sp. Strain CT16, Purification, and Characterization of a Deoxycytidine Deaminase Extremely Thermostable in the Presence of D,L…
A deoxycytidine deaminase that was extremely thermostable in the presence of dithiothreitol was found in a mesophilic bacterium isolated from soil and greatly stabilized the enzyme. Expand
Expulsion of uracil and thymine from the yeast Saccharomyces cerevisiae: contrasting responses to changes in the proton electrochemical gradient.
  • A. Eddy
  • Chemistry, Medicine
  • Microbiology
  • 1997
It was concluded that uracil exit is probably not driven by the proton gradient but may utilize ATP directly, and thymine uptake from the medium only occurred when delta mu H+ was dissipated, either by DNP or azide, or by manipulation of the external ionic environment. Expand
Evidence of a new phosphoryl transfer system in nucleotide metabolism
The proposed mechanism suggests a physiological role for the enzymes and for the AMP–AMP phosphotransferase reaction under conditions of extreme energy drain (such as hypoxia or temporary anoxia, as in cancer tissues) when the enzymes cannot display their conventional activity because of substrate deficiency. Expand


Mouse kidney cytidine deaminase. Purification and properties.
Abstract A nucleoside aminohydrolase was prepared in 60-fold relative purity from the nonparticulate fraction of mouse kidney by denaturation at 60°, fractionation with (NH4)2SO4, treatment withExpand
1. Crystalline hexokinase has been isolated from baker's yeast. 2. Crystalline hexokinase is a protein of albumin type of a molecular weight of 96,000. Its isoelectric point is at about pH 4.8. 3.Expand
Estimation of the molecular weights of proteins by Sephadex gel-filtration.
  • P. Andrews
  • Chemistry, Medicine
  • The Biochemical journal
  • 1964
The results are similar to those of previous studies, where the objective was to establish a cause-and-effect relationship, rather than a straightforward relationship between the number of cells and the content of the molecule. Expand