The enzymatic mechanism of asparaginase action has been explored using the acyl acceptor, hydroxylamine. Asparaginase catalyzed the synthesis of the hydroxamate from asparagine and more slowly from aspartic acid. P-Aspartohydroxamate was also a substrate for asparaginase. These reactions have rates which are linearly dependent on the concentration of the enzyme and can therefore be used as conv...

Gamma irradiation is used on Penicillium cyclopium in order to obtain mutant cells of high L-asparaginase productivity. Using gamma irradiation dose of 4 KGy, P. cyclopium cells yielded L-asparaginase with extracellular enzyme activity of 210.8 ± 3 U/ml, and specific activity of 752.5 ± 1.5 U/mg protein, which are 1.75 and 1.53 times, respectively, the activity of the wild strain. The enzyme wa...

AALL07P2 evaluated whether substitution of Erwinia asparaginase 25000 IU/m(2) for 6 doses given intramuscularly Monday/Wednesday/Friday (M/W/F) to children and young adults with acute lymphoblastic leukemia and clinical allergy to pegaspargase would provide a 48-hour nadir serum asparaginase activity (NSAA) ≥ 0.10 IU/mL. AALL07P2 enrolled 55 eligible/evaluable patients. NSAA ≥ 0.1 IU/mL was ach...

Exocytotic secretion of digestive enzymes from pancreatic acinar cells is elicited by physiological cytosolic Ca(2+) signals, occurring as repetitive short-lasting spikes largely confined to the secretory granule region, that stimulate mitochondrial adenosine triphosphate (ATP) production. By contrast, sustained global cytosolic Ca(2+) elevations decrease ATP levels and cause necrosis, leading ...

The aim of this investigation was to compare the efficacy of the permeabilization methods of microwave irradiation and potassium phosphate (KPi)-hexane solvent system in isolating the periplasmic enzyme, L-asparaginase II. Previous studies have shown that both methods enable the isolation of periplasmic proteins in Gram-negative bacteria. Periplasmic, cytoplasmic and membrane fractions of Esche...

An attempt is made in the present study to optimize the cultural conditions for the production of L-asparaginase by Fusarium oxysporum using submerged fermentation. Different fungal species were isolated and identified using standard manuals, screened initially for the production of extracellular L-asparaginase during their growth on Czapek’s Dox medium containing Lasparagine as sole source of ...

The most prevalent metabolite for the storage and transport of nitrogen used in protein production is L-asparagine; earlier studies, L-asparaginase enzyme derived from microorganisms was utilized to treat cancer cells; therefore, this study aimed purify describe Iraqi green bean seeds rather than microbial sources. enzymes were partially purified beans by short steps, including centrifugation c...

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 purifica...

We have previously hypothesized that higher systemic exposure to asparaginase may cause increased exposure to dexamethasone, both critical chemotherapeutic agents for acute lymphoblastic leukemia. Whether interpatient pharmaco-kinetic differences in dexamethasone contribute to relapse risk has never been studied. The impact of plasma clearance of dexamethasone and anti-asparaginase antibody lev...

Venous thrombosis is more frequent in patients treated for acute lymphoblastic leukaemia (ALL) than other malignancies and has distinctive causes, clinical features and remedies. The reported incidence varies from 1% to 36%, depending on the chemotherapy protocol and whether the reported cases are symptomatic or detected on screening radiography. The risk is thought to arise from increased thro...