Claims for Patent: 4,473,646

Summary for Patent: 4,473,646

Title:	Stereospecific asparaginases
Abstract:	There is described a method of separating an asparaginase rich fraction from a thermophilic microoganism and then to divide this fraction into its D- and L-asparaginases. Substantially pure crystals of the D-asparaginase were obtained.
Inventor(s):	Guy; Graeme R. (South Australia, AU), Morgan; Hugh W. (Hamilton, NZ), Daniel; Roy M. (Hamilton, NZ)
Assignee:	Development Finance Corp. of New Zealand (Wellington, NZ)
Application Number:	06/253,112
Patent Claims:	1. A D-asparaginase having a molecular weight of about 62,000, an isoelectric point of about 4.8, an optimum pH of about 9.5, no activity agatinst L-asparagine and no activity against L- or D-glutamine. 2. A D-asparaginase as claimed in claim 1, wherein said D-asparaginase is derived from Thermus aquaticus (VARIETY T-351), ATCC number 31,674. 3. An L-asparaginase having a molecular weight of about 80,000, as isoelectric point of about 4.6 an optimum pH of about 9.5, no activity against D-asparagine, and no activity against L- or D-glutamine. 4. An L-asparaginase as claimed in claim 3, wherein said L-asparaginase is derived from Thermus aquaticus (VARIETY T-351), ATCC number 31,674. 5. A process for deriving and separating D-asparaginase having a molecular weight of about 62,000, an isolectric point of about 4.8, an optimum pH of about 9.5, no activity against L-asparagine and no activity against L- or D-glutamine, and L-asparaginase having a molecular weight of about 80,000, an isoelectric point of about 4.6, an optimum pH of about 9.5, no activity against D-asparagine and no activity against L- or D-glutamine, said process comprising the steps of: (a) providing whole cells of Thermus aquaticus (VARIETY T-351), ATCC number 31,674; (b) subjecting said whole cells to a cell disrupting process to produce a mixture containing cell debris; (c) separating an asparaginase-rich fraction from said cell debris in said mixture formed by said cell disrupting process; (d) concentrating and purifying said asparaginase-rich fraction; and (e) separating D-asparaginase from L-asparaginase in said asparaginase-rich fraction. 6. A process according to claim 5, and further comprising subjecting D-asparginase separated from L-asparaginase in said asparaginase-rich fraction to purification steps. 7. A process according to claim 5, and further comprising subjecting L-asparaginase from which D-asparaginase has been separated to purification steps. 8. A process according to claim 5, wherein said cell disrupting process comprises subjecting said whole cells to pressure disruption. 9. A process according to claim 5 wherein said cell disrupting process comprises subjecting said whole cells to sonication. 10. A process according to claim 8 or 9, wherein said asparaginase-rich fraction is separated from said cell debris by centrifugation. 11. A process according to claim 10, wherein said centrifugation comprises a first low speed centrifugation to give a supernatant, followed by a second high speed centrifugation of said supernatant obtained from said low speed centrifugation. 12. A process according to claim 5, wherein said steps of concentrating and purifying said asparaginase-rich fraction comprise a series of dialyses and ion exchange processes. 13. A process according to claim 6, wherein said purification steps for purifying said D-asparaginase comprise ultrafiltration and ion exchange. 14. A process according to claim 7 wherein said purification steps for purifying said L-asparaginse comprise ultrafiltration and ion exchange. 15. A process according to claim 6 wherein said purification steps for purifying said D-asparaginase include, as a final purification step, the step of recrystalizing said D-asparaginase. 16. A process according to claim 7 wherein said purification steps for purifying said L-asparaginase include, as a final purification step, the step of recrystalizing said L-asparaginase.

Details for Patent 4,473,646

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Recordati Rare Diseases, Inc.	ELSPAR	asparaginase	For Injection	101063	01/10/1978		2001-09-25