Enzyme-containing polymers

Fig. 2. Diagram illustrating the immune polymer method, Dako s Envision . This is a two step, fast method which allows the use of more dilute primary antibody. The enzyme-containing polymer reagent is "universal" in that it contains antirabbit/mouse immunoglobulins and will bind to rabbit or mouse primary antibodies (A, immunoglobulin , peroxidase enzyme).

Biological Long-term stability of enzyme-containing polymer films 122... 

Fig. 14.29 Simultaneous deposition of enzyme-containing polymer spots using two microcounter electrodes (a) photograph of the set-up, (b) photograph of parallel generated enzyme structures...

Miranda and Berglund [79] used a food grade polymer, (hydroxypropyl)methyl cellulose (HPMC), and ammonium sulfate as additives for the recovery of recombinant a-amylase by flotation. The enzyme was removed from the liquid phase by partition to a salted-out HPMC phase and the enzyme-containing polymer floes were recovered by flotation. This system behaved in a manner similar to the flotation of mineral systems. The problem with this technique is the cost of the polymer and the separation of the enzyme from the polymer phase. Both of them complicate the process and increase the separation cost In general, for protein recovery and separation, especially in the pharmaceutical industry, it is not proper to add chemicals to the feed, because they have to be removed from the product completely and this separation causes problems and additive costs. 

Figure 17.17 Schematic representation of a single-compartment glucose/02 enzyme fuel cell built from carbon fiber electrodes modified with Os -containing polymers that incorporate glucose oxidase at the anode and bilirubin oxidase at the cathode. The inset shows power density versus cell potential curves for this fuel cell operating in a quiescent solution in air at pH 7.2, 0.14 M NaCl, 20 mM phosphate, and 15 mM glucose. Parts of this figure are reprinted with permission from Mano et al. [2003]. Copyright (2003) American Chemical Society.

The following protocols make use of the compounds adipic acid dihydrazide and carbohy-drazide to derivatize molecules containing aldehydes, carboxylates, and alkylphosphates. The protocols are applicable for the modification of proteins, including enzymes, soluble polymers such as dextrans and poly-amino acids, and insoluble polymers used as micro-carriers or chromatographic supports. 

Since the polymer has to be water-insoluble, its complete solution may occur only in an organic solvent. Casting the polymer from such a solution obviously can improve the properties of the resulting membrane. Thus, to prepare an enzyme containing casting solution the protein has to be exposed to organic solvent. 

As described in Sect. 7.1, novel hybrid block copolymers comprising on one hand a classical synthetic polymer and on the other hand a metal-containing polymer, a synthetic or natural (proteine, enzyme, etc.) polypeptide have recently been synthesized. Other hybrid block copolymers containing inorganic blocks, dendrimers, etc. will certainly be prepared and thoroughly investigated in the next few years. 

Large intestine 1.5 4-16 5.5-7 Contains specific enzymes that may be exploited for drug release. Polymers that are specifically degraded by such enzymes include saccharide-containing polymers or azopolymers... 

In the area of catalysis, the esterolysis reactions of imidazole-containing polymers have been investigated in detail as possible models for histidine-containing hydrolytic enzymes such as a-chymotrypsin (77MI11104). Accelerations are observed in the rate of hydrolysis of esters such as 4-nitrophenyl acetate catalyzed by poly(4(5)-vinylimidazole) when compared with that found in the presence of imidazole itself. These results have been explained in terms of a cooperative or bifunctional interaction between neighboring imidazole functions (Scheme 19), although hydrophobic and electrostatic interactions may also contribute to the rate enhancements. Recently these interpretations, particularly that depicted in Scheme 19, have been seriously questioned (see Section 1.11.4.2.2). 

Oxidative coupling polymerization provides great utility for the synthesis of high-performance polymers. Oxidative polymerization is also observed in vivo as important biosynthetic processes that, when catalyzed by metalloenzymes, proceed smoothly under an air atmosphere at room temperature. For example, lignin, which composes 30% of wood tissue, is produced by the oxidative polymerization of coniferyl alcohol catalyzed by laccase, an enzyme containing a copper complex as a reactive center. Tyrosine is an a-amino acid and is oxidatively polymerized by tyrosinase (Cu enzyme) to melanin, the black pigment in animals. These reactions proceed efficiently at room temperature in the presence of 02 by means of catalysis by metalloenzymes. Oxidative polymerization is observed in vivo as an important biosynthetic process that proceeds efficiently by oxidases. 

The control of the coupling of coniferyl alcohol has been attempted. When the metalloenzyme is mixed with coniferyl alcohol, a stepwise polymerization proceeds by dimerization and tetramerization, which result in the uncontrolled couplings. When the monomer is slowly supplied to the enzyme-containing reaction mixture, the radicals attack the terminal end of the polymer chain, because the diluted radical reacts preferentially to form the dimer by the coupling that means that comblike lignin grows on the cell wall. Some attempts have been reported to control the polymerization in the presence of cellulose as the matrix [23,24],... 

Imidazole is found in many enzymes as histidine residue. It plays a role of electron donor in biological systems. Imidazole is one of the nucleophiles, and many nucleophile-containing polymers have been synthesized as a mode of the enzyme such as a-chymotrypsin. 

This article describes the cooperative action in which the nucleophile-containing polymer is studied as the model of the enzyme. 

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