F. Liu et al., SYNTHESIS OF THERMAL PHASE-SEPARATING REACTIVE POLYMERS AND THEIR APPLICATIONS IN IMMOBILIZED ENZYMES, Polymer Journal, 25(6), 1993, pp. 561-567
This paper describes the synthesis of active ester copolymers from N-i
sopropylacrylamide (NIP) with N-acryloxysuccinimide (NAS), aminolysis
of active esters, and determination of their average molecular weights
. As a model, thermolysin was attached to the polymer to form soluble-
insoluble immobilized enzymes capable of being centrifuged above their
T(c), because poly(N-isopropylacylamide) (poly(NIP)) has a lower crit
ical solution temperature (T(c)) of about 31-33-degrees-C. The effects
of immobilization of enzymes have been studied including the amount o
f active ester, time, pH, temperature, and ratio of polymer to enzyme.
The tests of thermal stability and repeated precipitation and separat
ion showed that the use of T(c) as the technique of separation is poss
ible.