title: L-asparaginase release from Escherichia coli cells with aqueous two-phase micellar systems.
abstract: A method was proposed to release and separate L-asparaginase (EC 3.5.1.1) from Escherichia coli ATCC 11303 cells with aqueous two-phase micellar systems. The systems were composed of K2HPO4 and Triton X-100. The method combines enzyme release with enzyme purification. The influence of Triton X-100 concentration, K2HPO4 concentration, and pH on the release and partition of L-asparaginase was investigated. Experimental results showed that E. coli cells treated with 9.4% (w/v) K2HPO4 and 15% (w/v) Triton X-100 at 25 degrees C for 15-20 h released nearly 80% of the enzyme. Most of the released enzyme was partitioned to the bottom phase (phosphate-rich phase). The effects of Triton X-100 concentration, K2HPO4 concentration, and pH on cloud point were also studied. Electron micrography indicated that the chemical treatment altered the inner structure of E. coli cells significantly.
authors.affiliation: School of Pharmacy, Shanghai Jiao Tong University, Shanghai 200030, P. R. China.
authors.forename: Minjun
authors.initials: M
authors.lastname: Qin
authors.forename: Fengsheng
authors.initials: F
authors.lastname: Zhao
mesh_terms: D001215:Asparaginase / Q000737:chemistry*; D055592:Biophysical Phenomena; D001703:Biophysics; D003902:Detergents / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D008823:Micelles; D008854:Microscopy, Electron; D017830:Octoxynol / Q000494:pharmacology; D010710:Phosphates / Q000737:chemistry; D017680:Potassium Compounds / Q000737:chemistry; D013696:Temperature; D013997:Time Factors
chemical_list: D003902:Detergents; D008823:Micelles; D010710:Phosphates; D017680:Potassium Compounds; D017830:Octoxynol; C013216:potassium phosphate; D001215:Asparaginase