Chemical modification of L-asparaginase with comb-shaped copolymer of poly(ethylene glycol) derivative and maleic anhydride.
L-asparaginase from Escherichia coli, an antitumor enzyme, was chemically modified with a comb-shaped copolymer of poly(ethylene glycol) derivative and maleic anhydride (activated PM). The PM-modified asparaginase lost the immunoreactivity with retaining high enzymic activity and also prolonged the clearance time in blood. Intraperitoneal administration of PM-asparaginase markedly increased the mean survival-time of lymphoma L5178Y-bearing mice in comparison with that of unmodified asparaginase. Pretreatment of mice with PM-asparaginase before immunizing with unmodified asparaginase extremely suppressed the anti-asparaginase antibody production.
Saito
T
T
Department of Materials Science and Technology, Toin University of Yokohama, Japan.
Ueno
T
T
Sekine
T
T
Kodera
Y
Y
Hiroto
M
M
Matsushima
A
A
Nishimura
H
H
Inada
Y
Y
D000818:Animals; D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000627:therapeutic use*; D001215:Asparaginase / Q000032:analysis / Q000276:immunology / Q000627:therapeutic use*; D004926:Escherichia coli / Q000201:enzymology; D007940:Leukemia L5178 / Q000188:drug therapy*; D051379:Mice; D008807:Mice, Inbred BALB C; D008811:Mice, Inbred DBA; D011092:Polyethylene Glycols / Q000032:analysis / Q000627:therapeutic use*
D000970:Antineoplastic Agents; D011092:Polyethylene Glycols; C107021:PM-asparaginase; D001215:Asparaginase