Recombinant human glycosylasparaginase catalyzes hydrolysis of L-asparagine.
Glycosylasparaginase is a lysosomal amidase involved in the degradation of glycoproteins. Recombinant human glycosylasparaginase is capable of catalyzing the hydrolysis of the amino acid L-asparagine to L-aspartic acid and ammonia. For the hydrolysis of L-asparagine the Km is 3-4-fold higher and Vmax 1/5 of that for glycoasparagines suggesting that the full catalytic potential of glycosylasparaginase is not used in the hydrolysis of the free amino acid. L-Asparagine competitively inhibits the hydrolysis of aspartylglucosamine indicating that both the amino acid and glycoasparagine are interacting with the same active site of the enzyme. The hydrolytic mechanism of L-asparagine and glycoasparagines will be discussed.
Noronkoski
T
T
Department of Clinical Chemistry, Kuopio University Hospital, Finland.
Stoineva
I B
IB
Petkov
D D
DD
Mononen
I
I
D000641:Ammonia / Q000378:metabolism; D001216:Asparagine / Q000378:metabolism* / Q000494:pharmacology; D001224:Aspartic Acid / Q000378:metabolism; D001227:Aspartylglucosylaminase / Q000378:metabolism*; D001665:Binding Sites; D001667:Binding, Competitive; D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D011994:Recombinant Proteins / Q000378:metabolism*
D011994:Recombinant Proteins; D001224:Aspartic Acid; D001216:Asparagine; D000641:Ammonia; D001227:Aspartylglucosylaminase