Asparaginase

L-Asparaginase (L-​ASNase), a hydrolase that catalyzes the conversion of L-asparagine, used in acute lymphoblastic leukemia treatment. L-Asparaginase depletes L-asparagine from plasma resulting in inhibition of RNA and DNA synthesis with the subsequent blastic cell apoptosis[1].

Asparaginate is an alpha-amino-acid anion that is the conjugate base of asparagine, arising from deprotonation of the carboxy group. It is a conjugate base of an asparagine.|Asparaginase is a bacterial enzyme that is used as an antineoplastic agent, largely in the therapy of acute lymphocytic leukemia. L-asparaginase has many side effects, one of which is hepatic injury that is characterized by inhibition of hepatic protein synthesis and steatosis, which can be severe and lead to death from hepatic failure.|A hydrolase enzyme that converts L-asparagine and water to L-aspartate and NH3. EC 3.5.1.1.

The strain culture was Escherichia Coli A.S.1.357, beef juice medium 100ml, peptone 1g, sodium chloride 0.5g and agar 2～2.5g, cultured in test tube at 370C for 24h, eggplant bottle cultured for 8h, and flask cultured for 16h. Escherichia coli broth culture medium; 370C; 2d → strain culture broth strain seed culture medium with 10% corn steep liquor inoculation amount 1% to 1.5%, at 370C, aeration and stirring culture for 6-8h. Broth strain corn syrup; 370C; 6h→Seed culture Seed strain fermentation tank culture 10% corn syrup inoculation amount 8%, at 370C, aeration and stirring culture for 6-8h, centrifugation, separation of fermentation broth to obtain bacteria, Add 2 times the amount of acetone of the fermentation broth under stirring, press filter, sieving the filter cake, and air-dry it into dry powder. Seed strain corn syrup; 370C; 7h → fermenter culture fermentation broth with acetone → filter press, air-dried bacteria extraction, precipitation, add 10L of pH8 boric acid buffer (0.01mol/L) to each kilogram of dry bacteria powder, and 370C under stirring After incubation for 1.5 hours, cool to about 300C, adjust pH 4.2～4.4 with acetic acid solution (5mol/L), press filter, add 2 times the volume of the filtrate with acetone, let stand for 3～4h, wait until precipitation is complete, filter, Collect the precipitate and dry it to obtain the dried crude enzyme. Dry cell boric acid buffer; pH8; 370C→ extract HAc; pH4.3→precipitate dry crude enzyme heat treatment to take 1g of crude enzyme, add 20ml glycine solution (3g/L or 0.3g), adjust pH8.8, stir 1.5 h, centrifuge, collect the supernatant, heat to 600C, heat treatment for 30 min. Discard the precipitate by centrifugation, add 2 volumes of acetone to the supernatant, separate out the precipitate, centrifuge, collect the enzyme precipitate, add pH 8 phosphate buffer (0.01 mol/L), and then centrifuge to discard the insoluble matter to obtain the supernatant enzyme sediment. Dry crude enzyme glycine; 600; 30min→ heat treatment enzyme solution purification, lyophilization to adjust the pH8.8 enzyme solution, centrifugation to discard the precipitation, the supernatant is adjusted to pH 7.7, and polyethylene glycol (500g/ L is 50%) to make the concentration of polyethylene glycol reach 160g/L (16%). When the temperature is 2～50C, let it stand for 4～5d, there will be precipitation, and the precipitation will be separated by centrifugation. Add distilled water to dissolve it, add 4 times the amount of acetone to precipitate, repeat the same method once, and dissolve the precipitate with pH 6.4 phosphate buffer (0.05 mol/L) to obtain a refined enzyme solution. Adjust the pH to 5-5.2, add polyethylene glycol (500g/L), and repeat the treatment once. Then adjust the pH to 7.7, add polyethylene glycol (500 g/L) to dissolve, filter with a No. 6 vertical melting funnel under aseptic conditions, subpackage, freeze-dry, and then obtain the finished product of asparaginase for injection (day) , 10000U or 20000U each. Enzyme solution polyethanol; treatment with different pH → aseptic packaging of refined pyrogen-free enzyme solution → freeze-drying (day) asparaginase freeze-dried preparation

Used for leukopenia, thrombocytopenia and aplastic anemia caused by various reasons.

Molecular Weight:131.11
XLogP3:-2.8
Hydrogen Bond Donor Count:2
Hydrogen Bond Acceptor Count:4
Rotatable Bond Count:2
Exact Mass:131.04566709
Monoisotopic Mass:131.04566709
Topological Polar Surface Area:109
Heavy Atom Count:9
Formal Charge:-1
Complexity:128
Undefined Atom Stereocenter Count:1
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes