what is the function of the organic phase in the immobilization of enzyme using polyacrylamide?
- TigerLv 51 0 年前最佳解答
Polyacrylamide is the most widely used matrix for entrapping (or immobilizing) enzymes because of its advantages that it is non-ionic. (that is what you said of "organic phase")The consequence is that the properties of the enzymes are only minimally modified in the presence of the gel matrix. At the same time, the diffusion of the charged substrate and products is not affected, neither. However, dimethylaminopropionitrile, the polymerization initiator, is highly toxic and must be handled with great care. The requirement to purge the monomer solution with nitrogen is also troublesome, although not totally crippling. Secondly, the use of enzymes in organic synthesis brings about significant challenges. The entrapment method of immobilization is based on the localization of an enzyme within the lattice of a polymer matrix or membrane. It is done in such a way as to retain protein while allowing penetration of substrate. It can be classified into lattice and micro capsule types.
Lattice-Type entrapment involves entrapping enzymes within the interstitial spaces of a cross-linked water-insoluble polymer. Some synthetic polymers such as polyarylamide, polyvinylalcohol, etc... and natural polymer (starch) have been used to immobilize enzymes using this technique. Microcapsule-Type entrapping involves enclosing the enzymes within semi permeable polymer membranes. The preparation of enzyme micro capsules requires extremely well-controlled conditions and the procedures for micro capsulation of enzymes can be classified as: Interfacial Polymerization Method:Liquid Drying: Phase Separation:
2006-07-10 09:18:53 補充：
In Interfacial Polymerization Method, enzymes are enclosed in semi permeable membranes of polymers. An aqueous mixture of the enzyme and hydrophilic monomer are emulsified in a water-immiscible organic solvent.
2006-07-10 09:19:04 補充：
Then the same hydrophilic monomer is added to the organic solvent by stirring.
Polymerization of the monomers then occurs at the interface between the aqueous and organic solvent phases in the emulsion. The result is that the enzyme in the aqueous phase is enclosed in a membrane of polymer.參考資料： from Tiger & google.com