Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.5.1.4 (deaminase)
 5,113 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We previously described a lyophilized supernatant from germinated Candida albicans that blocks human neutrophil (PMN) O2- production and degranulation stimulated by several PMN agonists but does not block stimulation by PMA. In studies to further characterize this Candida hyphal inhibitory product (CHIP), we noted several physicochemical parallels with the purine nucleoside adenosine (Ado). A Sephadex G-10 semipurified fraction of CHIP had an absorption peak near 260 nm, an apparent m.w. of less than 400, and was resistant to boiling and proteases. Maximally effective doses of CHIP (100 micrograms/ml) and Ado (100 microM) blocked 0.1 microM FMLP-stimulated O2- production by 76.8 +/- 4.1 and 81.7 +/- 4.8%, respectively. Ado deaminase, known to inactivate Ado, reversed inhibition by both Ado and CHIP. Results were comparable for the effect of CHIP and Ado on FMLP-stimulated beta-glucuronidase and lactoferrin release. Activation of the respiratory burst by opsonized C. albicans yeast was also inhibited by CHIP and Ado, but the extent of inhibition was less than for FMLP. At yeast:PMN ratios of 4:1, 10:1, and 40:1, CHIP inhibited O2- by -3.8%, 14.3%, and 12.8%, respectively; Ado blocked production by 32.9%, 24.2%, and 11.5%, respectively. The effect of CHIP and Ado on Candida killing by PMN was compared using two viability assays in each of four experiments. Ado (100 microM) had no effect on killing, although CHIP (100 micrograms/ml) inhibited killing in the MTT assay at 15 and 45 min by 81.6 +/- 6.3 and 24.7 +/- 6.2%, respectively; as assayed by CFU, CHIP inhibited killing by 34.1 +/- 6.2 and 10.3 +/- 2.5%, respectively. The ability of CHIP to inhibit killing was not affected by adding Ado deaminase, providing additional evidence that an Ado-like effect by CHIP is not essential for killing inhibition. Killing of opsonized Streptococcus pneumoniae was also inhibited in a concentration-dependent manner. Reverse-phase HPLC of the semipurified fraction revealed a peak, eluting identically to authentic Ado, which was eliminated by adding Ado deaminase. Ado content of the G-10 fraction was sufficient to account fully for the FMLP-inhibitory activity. The antikilling activity was resistant to boiling and proteases but was eliminated by mild periodation. Fractions eluting from a Sephadex CL6B column between 0.8 and 2.0 x 10(6) m.w. had increased sp. act. for killing inhibition. Sp. act. increased as carbohydrate content increased, but killing inhibition by various Candida cell wall constituents was absent to modest compared to inhibition induced by CHIP.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:In vitro, Candida albicans releases the immune modulator adenosine and a second, high-molecular weight agent that blocks neutrophil killing. 131 20

Gene therapy may allow targeted delivery of tumoricidal drugs to treat pancreatic cancer. Cytosine deaminase (CD) is a bacterial enzyme that converts the nontoxic agent 5-fluorocytosine (5FC) to the active chemotherapeutic agent 5-fluorouracil (5FU). Neoplastic cells induced to express the CD gene treated with 5FC may generate locally high concentrations of 5FU while minimising systemic toxicity. Replication deficient adenovirus vector carrying the CD gene (AdCMV.CD) was tested for therapeutic efficacy against the murine pancreatic carcinoma cell line Pan02. Pan02 cells were infected in vitro with AdCMV.CD or null vector (Ad.-Null) and were examined for expression of CD messenger RNA (mRNA) (Northern blot) and CD enzymatic function (spectrophotometry). mRNA transcripts of the CD gene increased in a dose-dependent manner after infection with AdCMV.CD. Conversion of 5FC to 5FU at a multiplicity of infection (MOI) of 20 was measured to be 51% after a 48-hr incubation. Growth inhibition was measured by MTT assay and thymidine uptake. Pan02 growth in vitro treated with AdCMV.CD and 5FC was inhibited by 80% as compared to cells treated with Ad.Null and 5FC. An in vivo model of pancreatic cancer was established by injecting 2.5 x 10(5) PAN02 cells subcutaneously into the flanks of C57BL/ 6 mice. Seven days later AdCMV.CD was injected into each tumor and 5FC was administered for 10 days. Treatment of mice with AdCMV.CD and 5FC inhibited tumor growth compared to mice who received AdCMV.CD only or 5FC only. These data demonstrate the therapeutic efficacy of an enzyme prodrug strategy in experimental pancreatic cancer.
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PMID:In vivo adenoviral-mediated gene transfer in the treatment of pancreatic cancer. 920 75

This study was purposed to investigate the relationship between the catalysis of Bence Jones protein (BJP) in urine of patients with multiple myeloma(MM) and toxicity on the renal proximal tubular cells in vitro, and to explore the potential mechanism for the toxicity of BJP to renal impairment in patients with MM. The Michaelis-Menten constant (K(m)) and catalytic constant (k(cat)) of the amidase activity of BJP was calculated by Hanes equation. The LLC-PK1 cells were cultured with different concentration of BJP for 24 h, then proliferation of the cells were determined by MTT method and apoptosis were determined by flow cytometry. The results showed that the BJP from the MM patients with renal impairment significantly inhibited cell proliferation, as compared with that from MM patients without renal impairment. The BJP with higher k(cat) had higher toxicity to LLC-PK1 cells. BJP could induce apoptosis and necrosis of LLC-PK1 cells when reached a certain concentration and this effect enhanced with increase of BJP concentration. It is concluded that the catalysis of BJP and its toxicity to renal tubular epithelial cells has a positive correlation, and toxic effect of BJP on renal tubular epithelial cells results from inhibiting proliferation and inducing apoptosis and necrosis of the cells, which may be one of renal impairment mechanisms in MM patients.
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PMID:[Relationship between the catalysis of Bence Jones protein and renal impairment in patients with multiple myeloma]. 2254 Oct 94