Enzyme Conjugation with Polymers

Polymer-enzyme conjugates are investigated for applications in various areas including biocatalysis in nonaqueous media, for example, for the preparation of biosensors. In many other cases, biocompatible polymers are also used in enzyme conjugation for drug delivery. In the case of pharmaceutical industry, direct use of native enzymes barely show any detoxification effects, although enzymes are exquisite biocatalysts that decompose toxic substances. The main barrier is the instability under physiological environments. Therefore, those therapeutic enzymes are conjugated with polymer as carriers to improve the physiochemical properties.

Various polymers, such as poly(ethylene glycol) (PEG), polysaccharides, block copolymers and other synthetic polymers, are used in enzyme conjugation for different purposes. Among them, PEG is the most commonly used polymer for the construction of polymer-enzyme conjugates. PEGylation of enzymes is commonly achieved through reacting with lysine residues and is applied to enhance solubility, stability and activity. Dextran, a natural polysaccharide, has also been investigated as carriers for delivery of therapeutic enzymes. This type of conjugation, known as glycoconjugation, can prolong circulating time, increase protein stability, and reduce in vivo immunogenicity. Meanwhile, amphiphilic block copolymers are another class of polymers that are extensively studied due to their biocompatibility, biodegradability, low toxicity and prolonged circulation time when conjugated with enzymes.

Different polymers can bond to enzymes in different manners: i) carry a number of polymer chains on one and the same enzyme (e.g. PEG); ii) carry a single polymer chain (e.g. dextrin); iii) attach several enzymes to one and the same polymer chain (e.g. polylysine).

Creative Enzymes has extensive experience in providing enzyme conjugates with various polymers. Some examples include uricase, glucose oxidase, adenosine deaminase and many others. We control and quantify the conjugation coefficients to meet customer’s requests. We also provide detailed characterization data of the final polymer-enzyme conjugates. With standard purification procedures, we provide enzyme conjugates with highest purity.

• Preparation of enzyme conjugates with polymers.
• Enzyme conjugates isolation and purification.
• Quantification of number of PEG molecules bound
• Enzyme conjugates characterization.

Related sections

Enzyme Engineering and Modification

Figure 1 A schematic illustration of different types of polymer-enzyme conjugates.
(Biomacromolecules 2011)