Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

Crystalline glutaminase-asparaginase which is effective against solid as well as ascites tumors was prepared from soil isolate organism Pseudomonas 7A. This enzyme has a ration of Vmax for L-glutamine and L-asparagine of 2.0. The presence of glutamic acid in the growth medium is essential for optimal enzyme production and glucose inhibits the production of glutaminase-asparaginase. The purification procedure provides an overall yield of 40 to 45% from crude cell extract to homogeneous glutaminase-asparaginase and is adaptable to large scale production of the enzyme. The specific activity of homogeneous enzyme is 160 +/- 15 i.u./mg of protein and the E1% 280 is 9.8. No disulfide or sulfhydryl groups appear to be present on the enzyme. The isoelectric point of glutaminase-asparaginase by isoelectric focusing on ampholine polyacrylamide gel plates is 5.8. The Km values for L-glutamine and L-asparagine are 4.6 and 4.4 X 10(-6) M, respectively. The enzyme catalyzes the hydrolysis of the D isomers of glutamine and asparagine at 87 and 69% the rate of the respective L isomers. L-Glutamic acid gamma-monohydroxamate is hydrolyzed at approximately the same rate as L-glutamine. The enzyme is not inhibited by ethylenediaminetetraacetate (0.1 mM), L-glutamate (30 mM), or L-aspartate (30 mM). Ammonium sulfate (10 mM) inhibits the enzymatic activity. The plasma half-life of Pseudomonas 7A glutaminase-asparaginase if 13 hours in normal mice and 43 hours in mice infected with the lactate dehydrogenase-elevating virus.
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PMID:Purification and properties of a highly potent antitumor glutaminase-asparaginase from Pseudomonas 7Z. 0 41

Spleen antibody-forming cells of mice yield a 3- to 10-fold increase in their response to sheep erythrocyte antigen if they are acutely infected by lactate dehydrogenase-elevating virus. This early stimulation is replaced by a long-term inhibition of the antibody-forming cells as the viremia goes into its persisting chronic stage. These contrasting immunological phenomena are examined as contributing factors responsible for the enhancement by this virus of asparaginase (EC 3.5.1.1; L-asparagine amidolydrolase) therapy against leukemia in mice, and for the alteration of the susceptibility of mice to various neoplastic processes.
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PMID:Antibody-producing cells: virus-induced alteration of response to antigen. 108 81

Tyrosine phenol-lyase from Erwinia herbicola was purified with the goal of assessing its effect on growth of malignant melanoma. Ammonium sulfate-sodium citrate fractionation and diethylaminoethyl cellulose-hydroxylapatite chromatography were used. The purified enzyme was shown to reduce plasma tyrosine levels when administered to normal C57BL x DBA/2 F1 mice. The plasma half-life value of the enzyme was found to be 6 to 7 hr. Unlike results reported with glutaminase and asparaginase preparations, the lactate dehydrogenase-elevating virus had no significant influence on plasma clearance of tyrosine phenol-lyase. The enzyme significantly inhibited growth of established B-16 melanoma tumors.
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PMID:Some biological properties and an in vivo evaluation of tyrosine phenol-lyase on growth of B-16 melanoma. 124 96

We have demonstrated that biotinylated asparaginase binds to mouse monocytes. Also, asparaginase bound to peritoneal exudate, resident, splenic, bone marrow and pulmonary macrophages, but not to neutrophils or lymphocytes. Labelled asparaginase binding to peritoneal exudate macrophages was inhibited by 20-fold excess of unlabelled asparaginase. The binding of asparaginase to monocytes from mice injected with lactic dehydrogenase virus (LDV) or carrageenan was decreased. This decreased binding following treatment with LDV or carrageenan was reversed when mice were treated with diethylstilboestrol. In-vivo asparaginase clearance in mice infected with LDV was impaired as compared with that in uninfected mice. Neither strain nor age differences affected the binding to monocytes. The results suggest that the ability of asparaginase to bind to monocytes in vitro may reflect clearance function in vivo.
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PMID:Binding of asparaginase to mouse monocytes. 141 76

The objectives of this study were to determine prognostic factors for response to treatment, freedom-from-relapse (FFR) survival, and overall survival of 737 aggressive malignant lymphoma patients treated with the doxorubicin, cyclophosphamide, vindesine, bleomycin, methylprednisolone, methotrexate with leucovorin, ifosfamide, etoposide, asparaginase, and cytarabine (LNH-84) regimen; to construct a prognostic index with factors isolated by multivariate analyses; and to validate this prognostic index with another set of patients. Complete response (CR) was reached in 75% of LNH-84 patients, and 30% of them relapsed. With a median follow-up of 36 months, median FFR survival and median overall survival were not reached. Low serum albumin level, high tumoral mass, weight loss, bone marrow involvement, greater than or equal to 2 extranodal sites, and increased lactic dehydrogenase (LDH) level were associated with a low response rate. Advanced stage, increased LDH level, and nonlarge-cell histologic subtypes (diffuse mixed, lymphoblastic, and small non-cleaved) were statistically associated with a high relapse rate and short FFR survival. Increased LDH level, low serum albumin level, tumoral mass larger than 10 cm, greater than or equal to 2 extranodal sites, advanced stage, and age older than 65 years were statistically associated with short overall survival. Four of these parameters, namely, LDH level, stage, number of extranodal sites, and tumoral mass, were put together to construct a prognostic index. This index partitioned LNH-84 patients into three subgroups of good, intermediate, and poor prognosis (P less than .00001): CR rates of 93%, 83%, and 61%; relapse rates of 12%, 25%, and 45%; 3-year FFR survival of 87%, 73%, and 53%, and 3-year survival of 88%, 71%, and 41%, respectively. This prognostic index was applied to a test set of patients: 155 patients treated on protocols of the Nebraska Lymphoma Study Group. Using this index, these patients had 3-year FFR survival of 70%, 40%, and 22% (P = .0002) and 3-year survival of 79%, 52%, and 31% (P = .005). In patients with aggressive lymphomas, this simple prognostic index could distinguish between patients requiring intensive treatment such as autologous bone marrow transplantation in first complete remission and those who could be treated with standard regimens.
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PMID:Prognostic factors in aggressive malignant lymphomas: description and validation of a prognostic index that could identify patients requiring a more intensive therapy. The Groupe d'Etudes des Lymphomes Agressifs. 204 72

Flow cytometry was used to measure the binding of enzymes (i.e. lactate dehydrogenases 1 and 5, malate dehydrogenase, and asparaginase) to cells. Of the four enzymes studied, asparaginase showed the greatest binding. Single color analysis revealed that asparaginase bound best to preparations enriched in macrophages, and dual color analysis showed that the binding was to macrophages. Studies on continuous cell lines revealed that asparaginase bound to one mouse macrophage line, but not to another or to murine fibroblasts. Inoculation of mice with lactic dehydrogenase virus, a virus that infects macrophages, decreased the in vivo clearance of asparaginase from the circulation and the in vitro binding of asparaginase to peritoneal macrophages. It is concluded that flow cytometry can be used to study the binding of enzymes to cells, to identify the cell type to which the enzyme binds, and to measure changes in the capacity of cells to bind enzymes.
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PMID:Flow cytometry to identify cell types to which enzymes bind. Effect of lactic dehydrogenase virus on enzyme binding. 238 55

Fifty-nine consecutive previously untreated adult patients with acute lymphoblastic leukemia (ALL) were entered onto a prospective single-arm trial of doxorubicin, vincristine, prednisone, and asparaginase (HOP-L) induction therapy followed by CNS prophylaxis and 3 years of maintenance therapy. Consolidation therapy was not administered. The study population included a large number of older (greater than 50 years) patients. Seventy-five percent of patients achieved complete remission. With a median follow-up of 6 years, the median duration of complete remission is greater than 4 years, with 53% of patients expected to remain in remission at both 3 and 5 years. Overall, median survival duration is 27.9 months, with 45% and 35% of all patients expected to survive 3 and 5 years, respectively. Multivariate analysis identified patients with T-cell disease and mediastinal masses (P less than .001) and those with low values of lactic dehydrogenase (LDH) (P = .057) as being at greatest risk of relapse. Therapy was well tolerated by patients under age 35, but older patients suffered appreciable mortality. We conclude that this treatment program is effective therapy for adult ALL, yielding a large proportion of durable remissions despite the exclusion of consolidation therapy.
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PMID:Adult acute lymphoblastic leukemia: results of the Iowa HOP-L protocol. 264 41

Forty-four adult patients with lymphoblastic lymphoma (LBL) were treated according to one of two protocols. Both included (1) induction with cyclophosphamide, doxorubicin, vincristine, prednisone, and L-asparaginase; (2) CNS prophylaxis; and (3) maintenance therapy with methotrexate (MTX) and 6-mercaptopurine. In the second protocol, CNS prophylaxis began earlier than in the first protocol and included cranial irradiation and intrathecal (IT) MTX rather than simultaneous high-dose systemic and IT MTX. The overall response rate was 100% (95% complete). With a 26-month median follow-up, the 1-and 3-year actuarial freedom from relapse (FFR) for the composite patient group was 70% and 56%, respectively. The incidence of CNS relapse was reduced from 31% in the first protocol to 3% in the second protocol (P = .04, Gehan). Patients can be assigned retrospectively to low (n = 19) and high (n = 25) risk prognostic groups, as indicated by a multivariate analysis of pretreatment prognostic factors. High-risk is defined by Ann Arbor stage IV disease with bone marrow or CNS involvement or initial serum lactate dehydrogenase (LDH) concentration of greater than 300 IU/L (normal, less than 200). FFR of low- and high-risk groups at 5 years are 94% and 19%, respectively (P = .0006). Low-risk patients are highly curable using this approach to adult LBL. More intensive treatment for high-risk patients is warranted.
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PMID:Treatment of lymphoblastic lymphoma in adults. 377 16

Sixty-two patients with aggressive non-Hodgkin's lymphoma (diffuse mixed, diffuse large cells, non-cleaved small cells (Burkitt-like), immunoblastic, lymphoblastic and other non-epidermotropic T lymphomas) were treated by intensive sequential chemotherapy combining heavy induction treatment (modified CHOP-Bleo), sequential consolidation treatment (cytosine arabinoside and thioguanine, then high-dose methotrexate and L-asparaginase) and final reinforcement (CVAP-Bleo). Complete remission was achieved in 59 patients (95%); 11 patients (18%) relapsed. Two patients died during the induction phase and one failed to respond. Two patients died of an unrelated disease while in complete remission. Blood toxicity was tolerable and treatment could be conducted without problems in most cases. The median survival cannot be reached with a 14-months follow-up, but the survival rate seems to plateau at 70%. The only two prognostic factors identified were poor general condition and high serum lactate dehydrogenase levels.
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PMID:[Highly malignant non-Hodgkin's lymphoma. Treatment by intensive sequential chemotherapy]. 619 54

Immunochemical techniques with enzymes as the antigen have grown in frequency during the last few years. These techniques have allowed evaluation of enzymes in the presence of endogenous inhibitors. Among those enzymes measured by immunochemical techniques and which have found diagnostic application, mention will be made of alkaline phosphatase (with particular reference to the intestinal, placental, and Regan isoenzymes), lactate dehydrogenase (in which renewed interest has developed due to techniques for specifically measuring the LD-1 isoenzyme), aspartate aminotransferase (of which the cytosolic and mitochondrial forms can now be independently measured by immunochemical techniques), acid phosphatase (for which a specific immunochemical assay for the prostatic enzyme has been widely introduced in diagnostic laboratories), and creatine kinase (for which a variety of immunochemical techniques to measure the M- and B-subunits are now part of standard laboratory assays). Other enzymes which will be discussed in this review include phosphohexose isomerase, amylase, ribonuclease, and lysozyme (muramidase). Finally, the use of enzymes, particularly asparaginase, in the chemotherapy of cancer will be outlined.
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PMID:Immunoassay of enzymes--an overview. 634 26


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