• Journal of Microbiology and Biotechnology
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• 제22권3호
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• pp.292-300
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• 2012

We report the expression, purification, and characterization of L-asparaginase (AnsA) from Rhizobium etli. The enzyme was purified to homogeneity in a single-step procedure involving affinity chromatography, and the kinetic parameters $K_m$, $V_{max}$, and $k_{cat}$ for L-asparagine were determined. The enzymatic activity in the presence of a number of substrates and metal ions was investigated. The molecular mass of the enzyme was 47 kDa by SDS-PAGE. The enzyme showed a maximal activity at $50^{\circ}C$, but the optimal temperature of activity was $37^{\circ}C$. It also showed maximal and optimal activities at pH 9.0. The values of $K_m$, $V_{max}$, $k_{cat}$, and $k_{cat}/K_m$ were $8.9{\pm}0.967{\times}10^{-3}$ M, $128{\pm}2.8$ U/mg protein, $106{\pm}2s^{-1}$, and $1.2{\pm}0.105{\times}10^4M^{-1}s^{-1}$, respectively. The L-asparaginase activity was reduced in the presence of $Mn^{2+}$, $Zn^{2+}$, $Ca^{2+}$, and $Mg^{2+}$ metal ions for about 52% to 31%. In addition, we found that $NH_4{^+}$, L-Asp, D-Asn, and ${\beta}$-aspartyl-hydroxamate in the reaction buffer reduced the activity of the enzyme, whereas L-Gln did not modify its enzymatic activity. This is the first report on the expression and characterization of the L-asparaginase (AnsA) from R. etli. Phylogenetic analysis of asparaginases reveals an increasing group of known sequences of the Rhizobial-type asparaginase II family.

• Journal of Microbiology and Biotechnology
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• 제26권6호
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• pp.1115-1123
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• 2016

_L-Asparaginase (E.C. 3.5.1.1) is an enzyme involved in asparagine hydrolysis and has the potential to effect leukemic cells and various other cancer cells. We identified the _L-asparaginase gene (_L-ASPG86) in the genus Mesoflavibacter, which consists of a 1,035 bp open reading frame encoding 344 amino acids. Following phylogenetic analysis, the deduced amino acid sequence of _L-ASPG86 (_L-ASPG86) was grouped as a type I asparaginase with respective homologs in Escherichia coli and Yersinia pseudotuberculosis. The _L-ASPG86 gene was cloned into the pET-16b vector to express the respective protein in E. coli BL21 (DE3) cells. Recombinant _L-asparaginase (r-_L-ASPG86) showed optimum conditions at 37-40℃, pH 9. Moreover, r-_L-ASPG86 did not exhibit glutaminase activity. In the metal ions test, its enzymatic activity was highly improved upon addition of 5 mM manganese (3.97-fold) and magnesium (3.35-fold) compared with the untreated control. The specific activity of r-_L-ASPG86 was 687.1 units/mg under optimum conditions (37℃, pH 9, and 5 mM MnSO₄).

• 한국임상약학회지
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• 제27권3호
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• pp.143-149
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• 2017

Background: L-asparaginase (L-ASP) is a critical agent for the treatment of acute lymphoblastic leukemia and lymphoma, which is associated with serious toxicities including hypersensitivity, pancreatitis and thrombosis. Methods: To evaluate the toxicity of L-ASP in real clinical settings, we included the patients with L-ASP adverse drug reactions (ADRs) reported in a regional pharmacovigilance center of Seoul St. Mary's hospital from January 2014 to December 2015. Results: A total of 83 cases of L-ASP related ADRs were reported in 54 patients. Of these 83 cases, 65 cases (78.3%, 65/83) were spontaneously reported and 18 cases (21.7%, 18/83) were detected by further medical records review. Of the patients with ADRs, pediatric patients accounted for 83.3% of the cases (45/54) and median age was 9 years. The most common clinical manifestations of ADRs were hematology manifestations (31.3%, 26/83), followed by hepatobiliary manifestations (18.1%, 15/83). Thirty-four serious ADRs were reported in 19 patients. The sserious ADR group showed significantly longer hospitalization and higher rate of discontinuation of L-ASP than the non-serious ADR group (p = 0.005, 0.03). The most common clinical manifestations of serious ADRs were hepatobiliary manifestations (41.2%, 14/34). In total, 8 cases (9.6%, 8/83) of unlabeled ADRs were identified. They were serious ADRs. Conclusion: We identified unlabeled serious ADRs of L-ASP. Also, correlations were observed between serious ADRs and length of hospitalization, discontinuation rate respectively. Further investigations and developed spontaneous ADR reporting systems are needed to evaluate these correlations.

• 한국해양생명과학회지
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• 제7권2호
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• pp.121-128
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• 2022

L-asparaginase (ASNase) is a therapeutic enzyme used to treat acute lymphoblastic leukemia. Currently, the most widely used ASNases are originated from bacteria. However, owing to the adverse effects of bacterial ASNases, new resources for ASNase production should be explored. Fungal enzymes are considered efficient and compatible resources of natural products for diverse applications. In particular, fungal species belonging to the genus Trichoderma are well-known producers of several commercial enzymes including cellulase, chitinase, and xylanase. However, enzyme production by marine-derived Trichoderma spp. remains to be elucidated. While screening for extracellular ASNase-producing fungi from marine environments, we found four strains showing extracellular ASNase activity. Based on the morphological and phylogenetic analyses using sequences of translation elongation factor 1-alpha (tef1α), the Trichoderma isolates were identified as T. afroharzianum, T. asperellem, T. citrinoviride, and Trichoderma sp. 1. All four strains showed different ASNase activities depending on the carbon sources. T. asperellem MABIK FU00000795 showed the highest ASNase value with lactose as a carbon source. Based on our findings, we propose that marine-derived Trichoderma spp. are potential candidates for novel ASNase production.

• 약학회지
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• 제39권2호
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• pp.113-117
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• 1995

Garlic tissue cells are employed for the conversion of L-asparagine into ammonia. An ammonia gas electrode is used as a detector. The effect of pH, buffer solution, temperature and life time of electrode to have used were investigated in order to optimize the electrode response. The combination of L-asparaginase in garlic tissue cells and the gas electrode response linearly to Lasparagine over the concentration range 1.0$\times$10$^{-4}$~1.0$\times$10$^{-1}$ M with a slope of 72.0 mV/decade and is selective with respect to other L-amino acids.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2007년도 제48회 학술심포지움 및 추계국제학술대회
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• pp.110.2-110.2
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• 2007

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• Asian Pacific Journal of Cancer Prevention
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• 제16권11호
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• pp.4515-4520
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• 2015

GELOX (gemcitabine, oxaliplatin and L-asparaginase) regimen showed an impressive result in our previous study, but the effect of this new regimen is still dissatisfying for some patients, so it is necessary to identify which patients will benefit from this regimen. A total of fifty-one cases with nasal natural killer/T-cell lymphoma receiving initial GELOX chemotherapy were enrolled in this study. The ki-67 expression detected by immunohistochemistry (IHC) in the specimens ranged from 10% to 90%, with a median value of 70%, so cases higher than the median value (${\geq}70%$) were defined as high ki-67 expression, and the others were designated as low ki-67 expression. The response rate had no statistical difference between low ki-67 expression group and high ki-67 expression group (P=0.291) though the value in the former group was relatively high. After a median follow-up of 18.03 months, the 3-year progression-free survival (PFS) for patients with low ki-67 expression was significantly higher than those with high ki-67 expression (83.8% vs. 47.9%, P=0.038). In the stage I/II subgroup, 3-year PFS and overall survival (OS) were statistically higher in the patients with low ki-67 expression than those with high ki-67 expression. Multivariate analysis revealed high ki-67 expression was an independent prognostic factor for PFS. These results suggest that low ki-67 expression can predict a good response of GELOX in these patients, and the combination of ki-67 expression and early stage is helpful to identify an excellent prognosis subgroup from patients receiving GELOX in this disease.

• Asian Pacific Journal of Cancer Prevention
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• 제17권7호
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• pp.3155-3160
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• 2016

Background: L-asparaginase (ASNase) is commonly used in the treatment of acute lymphoblastic leukemia (ALL) and natural killer (NK)/T-cell lymphoma. This study was designed to describe the incidence of toxicity associated with ASNase in Asian adults. Secondary objectives were to investigate the management and impact of toxicity on subsequent ASNase use, and to compare the actual management against current recommendations. Materials and Methods: In this retrospective, multi-center, observational study, Asian patients ${\geq}18$ years old who received ${\geq}1$ dose of the native E. coli ASNase from 2008 to 2013 were included. Patients were excluded if they did not receive ASNase. Endpoints of this study were development of specific toxicities, whether ASNase was discontinued or re-challenged, and developmentg of recurrent toxicity. All data analyses were performed using SPSS version 20.0. Results: A total of 56 patients were analyzed. Mean (${\pm}SD$) age was 36.2 (${\pm}15.2$) years old, with 62.5% being males, 55.4% with ALL and 28.6% with NK/T-cell lymphoma. Hypersensitivity (12.5%) was associated with the highest incidence of toxicity (6 out of 7 patients had Grade 3 and 4 toxicity), followed by 10.7% for hepatic transaminitis, 3.6% for non-CNS thrombosis and 1.8% each for hyperbilirubinemia and pancreatitis. Hypersensitivity recurred in the 3 patients who were re-challenged with E. coli ASNase. Conclusions: ASNase is associated with a wide range of toxicities, with hypersensitivity being the most commonly observed among Asian adult patients.

• 대한수의사회지
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• 제24권1호
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• pp.25-29
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• 1988

An attempt to treat canine lymphosarcoma with the combination chemotherapy protocol consisting of cyclophosphamide, vincristine, L-asparaginase and methotrexate was made for 3 weeks. The chemotherapy to the patient showed good responses such as better cha

• 한국작물학회:학술대회논문집
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• 한국작물학회 2002년도 추계 학술대회지
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• pp.46-46
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• 2002