Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.5.1.1 (asparaginase)
 2,695 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Homogenous deamidase AG from Pseudomonas fluorescens AG was found to be a glycoprotein with molecular weight of about 13,000 daltons. The molecule consists apparently of four similar or identic subunits with molecular weight of about 30,000 daltons. The amino acid composition, N-terminal amino acids, the amount of chymotryptic peptides, containing 14C-carboxymethyl cysteine were studied. The enzyme exhibited distinct antitumoral effect on cells of Burkitt's lymphoma, sensitive to asparaginase, but did not exhibit marked cytotoxic action on cells of human ovarium cancer CaOV line, resistant to asparaginases.
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PMID:[Physico-chemical properties of deamidase AG from Pseudomonas fluorescens AG possessing antitumor activity]. 41 Dec 53

The development of microbial enzymes for cancer therapy presents difficulties not commonly experienced with biological drugs. The development of the enzyme asparaginase from Escherichia coli in the USA and of the serologically different asparaginase from the plant pathogen Erwinia carotovora in this Establishment, has not only added to the choice of antileukaemia drugs but also provided a valuable guide to the selection and development of new therapeutic enzymes. Our own programme has led to the study of enzymes that degrade other amino acids (glutamine, arginine, phenylalanine and tyrosine) that appear to be important to certain leukaemia cells. Microbes with only remote associations with man were considered as a source of these to minimize initial immunological sensitivity. In the case of erwinia asparaginase the benefits of this have probably included a lower incidence of anaphylaxis compared with the escherichia enzyme. The selection of a stable, high-affinity enzyme that operates efficiently under physiological conditions ensures effective depletion of a circulating amino acid but the choice is very limited. It is also difficult to assess from laboratory tests the likely persistence, toxicity and efficacy of the enzyme in clinical use and to arrive at meaningful biological tests for the quality control of the finished product. Some of the difficulties will be described and proposals made for criteria of acceptance for this type of drug in experimental use.
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PMID:Amino acid degrading enzymes for cancer therapy. 41 22

The L-cyst(e)ine requirements of normal and malignant cells are reviewed and expanded within the context of establishing whether the measurement of gamma-cystathionase levels constitutes a predictive test for tumor sensitivity to L-cyst(e)ine depletion. The ability of both purified L-cysteine desulfhydrase and gamma-cystathionase to inhibit the growth of the L-cystine-dependent L1210 leukemia in culture is presented, as well as approaches to circumvent the limitations of these enzymes for in vivo therapy. The ability of proparagylglycine to inhibit L-cysteine biosynthesis in vivo is reviewed for its possible use in combination therapy. In addition, the ability of poly D,L-alanine modification of Escherichia coli L-asparaginase to increase the plasma half-life in mice tenfold as well as to decrease the immunogenicity of the enzyme is presented.
Cancer Treat Rep 1979 Jun
PMID:L-cyst(e)ine requirements of malignant cells and progress toward depletion therapy. 46 47

The effect of L-glutamine and L-asparagine depletion by Acinetobacter L-glutaminase-L-asparaginase on the toxicity and antitumor activity of L-(alphaS,5S)-alpha-amino-3-chloro-4,5-dihydro-5-isoxazoleacetic acid (NSC-163501) was tested in mice. The LD50 of six daily doses of NSC-163501 in BDF1 female mice decreased from 7.5 to 0.3 mg/kg/day by combination treatment with the enzyme. Enzyme therapy also decreased the dose of NSC-163501 needed for maximal prolongation of survival in these mice inoculated with L1210 leukemia. Nevertheless, the combination did not prolong survival in L1210-bearing mice beyond that of higher doses of NSC-163501 alone. In contrast, the combination of enzyme plus NSC-163501 inhibited the growth of established sc implanted Ehrlich ascites carcinoma in ICRf male mice much more than either agent alone. Treatment with Acinetobacter L-glutaminase-L-asparaginase decreased the L-asparagine and L-glutamine levels in acid extracts of the Ehrlich tumor. NSC-163501 did not affect the amide levels or alter the decrease produced by enzyme therapy.
Cancer Treat Rep 1979 Jun
PMID:Enhanced effect of an L-glutamine antagonist, L-(alphaS,5S)-alpha-amino-3-chloro-4,5-dihydro-5-isoxazoleacetic acid, by Acinetobacter L-glutaminase-L-asparaginase. 46 50

An L-glutaminase-L-asparaginase from Achromobacter has been rendered nonimmunogenic by the covalent attachment of polyethylene glycol (PEG) to nonessential amine groups of the enzyme. PEG-L-glutaminase-L-asparaginase exhibits a greatly enhanced half-life in the bloodstream compared to the unmodified enzyme in normal mice, and is effective in prolonging the survival of BDF1 mice inoculated ip with L5178Y cells. PEG-L-glutaminase-L-asparaginase appears rapidly in the blood following ip injection.
Cancer Treat Rep 1979 Jun
PMID:Treatment of L5178Y tumor-bearing BDF1 mice with a nonimmunogenic L-glutaminase-L-asparaginase. 46 51

Since asparagine has been found to inhibit growth of some tumors and to inhibit or delay mitotic activity in other cells, we have studied the effect of asparaginase and of deprivation of some essential amino acids (Arg, Asn, Leu, Ile, Trp) on nucleic acid and protein synthesis in an asparagine-requiring strain of BHK/21 cells. We find that: (1) there is no essential difference in the pattern of synthesis following deprivation of any of the amino acids we tested; (2) that the effect of asparaginase is similar to that of amino acid deprivation; (3) that RNA synthesis is inhibited more rapidly than DNA or protein synthesis; (4) that after 10 hr of amino acid starvation, DNA synthesis is almost totally (reversibly) inhibited while RAN synthesis continues at about 30-50% and protein at about 100% of the initial value.
Cancer Biochem Biophys 1977
PMID:The effect on macromolecular synthesis of amino acid deprivation of hamster kidney cells. 61 19

RNA synthesis in mouse leukemia L5178Y cells was inhibited depending upon the time of treatment by blasticidin S or by ricin, which inhibits specifically protein synthesis. When blasticidin S or ricin blocked protein synthesis by more than 90% of the control, marked accumulation of monosome was accompanied by the decrease of pulse-labeled RNA (20% of that in the control) in the polysomes and monosome fraction. The size distribution of pulse-labeled RNA among polysomal fractions including monosome obtained from the cells treated with either blasticidin S, ricin of L-asparaginase showed that the size of presumptive mRNA was shifted from 18 S to 9--10 S. TReatment of a blasticidin S-resistant (Bla-R) subline derived from L5178Y cells (Kuwano, M., Matsui, K., Takenaka, K., Akiyama, S. and Endo, H. (1977) Int. J. Cancer 20, 296--302) with L-asparaginase or ricin induced smaller size (9--10 S) RNA, but treatment of Bla-R cells with blasticidin S did not. Such shorter RNA fragments could not be observed even when cellular protein synthesis was inhibited by treatment for short time with blasticidin S (40--80% of the control activity). Smaller RNA fragments accumulated after drastic inhibition of protein synthesis were composed of 74% of polyadenylate sequence lacking poly(A)(-)RNA with peak of approx. 10 S and 26% of polyadenylate sequence containing poly(A)(+)RNA with a peak of 18 S, whereas cytoplasmic polysomal RNA of the control contained 46% poly(A)(+) with a peak of 18 S and 54% poly(A)(-)RNA with a 10--18 S peak. Cytoplasmic poly(A)(+)RNA degraded biphasically with half-lives of approx. 2 h and 8--10 h in exponentially growing mouse cells. However, in degradation of poly(A)(+)RNA molecules being formed in the cells pretreated with blasticidin S for 3 h, the rapid phase of decay with a half-life of approx. 2 h was interrupted by successively appearing poly(A)(+)RNA with a longer half-life of 8--10 h in cytoplasm. However, when the cells were pretreated with blasticidin S for 6 h, there appeared no poly(A)(+)RNA population with the rapid-decay in cytoplasm.
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PMID:The synthesis and degradation of presumptive messenger RNA in cultured mouse leukemia cells during the inhibition of protein synthesis. 71 32

Combination chemotherapy with cytosine arabinoside, cyclophosphamide and L-asparaginase (Asnase) was given to 22 children with acute lymphocytic leukaemia (ALL) with a white-cell count greater than 30 X 10(9)/1, and other features suggestive of poor prognosis. Complete remission was induced in all patients--in 19 after 2 courses of chemotherapy and in the remainder after a third course. During induction, neutropenia occurred in 18 and severe infection in 3. Anaphylaxis to Asnase occurred in 8 patients after the second course and one other had transient Asnase-induced diabetes. All patients received central-nervous-system prophylaxis after achieving remission, during which they were also treated with weekly vincristine and a 2-week course of prednisolone. Continuation therapy consisted of short cycles of intermittent chemotherapy and BCG inoculation or long cycles of intermittent chemotherapy +/- BCG. Life-table analysis shows 46% complete remission rate at 28 months, with 6 patients all in complete remission followed up between 28 and 41 months. There were minimal complications of continuation therapy, and BCG inoculation was well tolerated.
Br J Cancer 1978 Nov
PMID:Treatment of childhood lymphocytic leukaemia with high white-cell counts. 72 50

The relative antineoplastic effectiveness of E. coli and Erwinia asparaginases was tested against lymphoid leukemias EARAD-1 and L5178Y/CA55. E. coli and Erwinia asparaginases had similar clearance rates from plasma in mice, and at a dose of 250 IU/kg body weight both enzymes lowered plasma asparagine to undetectable levels. Nevertheless, the dosage of Erwinia asparaginase needed to cause similar prolongation of median survival time in leukemic mice was at least twice that of E. coli asparaginase. The factors which may be responsible for the more potent therapeutic effectiveness of the E. coli asparaginase are discussed.
Cancer Biochem Biophys 1976 May
PMID:A comparative study of the antitumor effectiveness of E. coli and Erwinia asparaginases. 78 92

A retrospective study was undertaken comparing the frequency and severity of anaphylactic reactions to E. coli-derived and Erwinia-derived asparaginase given intravenously on a weekly dosage schedule. Both drugs were found to produce life-threatening hypersensivity reactions with the chance of reaction per dose administered being almost identical--8% for each dose administered. Eleven of 31 patients (35%) experienced anaphylactic reactions, 9/27 (33%) with E. coli and 3/10 (30%) with Erwinia asparaginase, with one patient suffering anaphylaxis to both preparations. A marked increase in the percentage of patients having reactions occurred after the fourth dose of either preparation, with the incidence per dose increasing from 3.3% with the first dose to 32% on the fifth and subsequent doses. Rationale for an antibody-mediated allergic reaction is presented to explain the data.
Cancer 1976 Oct
PMID:Comparison of anaphylactic reactions to asparaginase derived from Escherichia coli and from Erwinia cultures. 79 76


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