Catalyzes the hydrolysis of L-asparagine into L-aspartate and ammonia. Displays no glutaminase activity, a highly desirable therapeutic property. H2O + L-asparagine = L-aspartate + NH4(+) kcat is 870 sec(-1) (at pH 9.0 and 80 degrees Celsius) (PubMed:20370616). kcat is 888.6 sec(-1) (at pH 8.2 and 80 degrees Celsius) (PubMed:22166247). kcat is 17.98 sec(-1) (at pH 7.4 and 37 degrees Celsius) (PubMed:22166247). Optimum pH is 9.0. Optimum temperature is around 90 degrees Celsius (PubMed:20370616). Thermostable (PubMed:20370616, PubMed:25862541). The extreme thermal stability of this enzyme is due to the presence of high intersubunit associative forces supported by extensive H-bonding and ionic interactions network (PubMed:25862541). Homodimer. Consists of distinct N- and C-terminal domains (NPfA and CPfA, respectively), connected by a linker. NPfA acts as specific internal chaperone by mediating folding of its own C-domain (CPfA), but also functions as a non-specific molecular chaperone by preventing aggregation of unrelated proteins (PubMed:23551356, PubMed:25862541). The linker is dispensable since domains of this enzyme can assemble without the linker into a conjoined tetrameric form that exhibits higher activity than the parent enzyme, while each domain is inactive independently. The structural integrity of the conjoined enzyme is maintained through domain-domain interactions rather than the covalent linker (PubMed:25478837). Absence of glutaminase activity, higher stability, and mesoactivity makes P.furiosus L-asparaginase and its mutants promising candidates for clinical as well as industrial usage. Microbial L-asparaginase is considered as an important biopharmaceutical drug enzyme in the treatment of childhood acute lymphoblastic leukemia (ALL). It functions by reducing the availability of circulatory L-asparagine to tumor cells. The principle behind the cytotoxic effect of L-asparaginase stems from the fact that the leukemic lymphoblastic tumor cells and other blood tumor cells are auxotrophs towards the L-asparagine and exhibit low L-asparagine synthetase (ASNS) activity for de novo synthesis of L-asparagine. Therefore, these tumor cells are required for exogenous supply of L-asparagine for proliferation and survival. L-Asparaginase has also been used for making a diagnostic biosensor as the amount of ammonia produced by the action of the enzyme directly correlates to the level of L-asparagine in a patient's blood (Probable). P.furiosus L-asparaginase and its mutants show significant killing of cultured human leukemic cell lines HL60, MCF7, and K562 (PubMed:22166247). Belongs to the asparaginase 1 family.