The First Demonstration of a Prokaryotic Glycosylasparaginase

Glycosylasparaginase was purified to near homogeneity from intracellular lysates of Flavobacterium meningosepticum. The enzyme is a heterodimer with an estimated molecular weight of 38 kDa and consists of one α-subunit (18 kDa) and one β-subunit (16 kDa). The β-subunit of the Flavobacterium enzyme has a direct evolutionary relationship to the β-subunit of mammalian glycosylasparaginases as evidenced by: (1) strong cross-reactivity with antibodies made to the denatured rat β-subunit, (2) a high degree of homology with the amino-terminus of the corresponding eukaryotic enzymes, and (3) irreversible inactivation with 5-diazo-4-oxo-L-norvaline, a reagent known to react with the catalytic amino-terminal threonine residue on the β-subunit of a mammalian glycosylasparaginase.