Method For the Preparation of Cross Linked Protein Crystals

A protein such as an enzyme is immobilized by crosslinking crystals of the protein with a multifunctional crosslinking agent. The crosslinked protein crystals may be lyophilized for storage. A preferred protein is an enzyme such as amyloglucosidase, Horse radish peroxidase, plant peroxidases etc. Crosslinked enzyme crystals preferably retain at least 90% activity after incubation for three hours in the presence of a concentration of protease that causes the soluble uncrosslinked form of the enzyme to lose at least 92% of its initial activity under the same conditions. Enzyme crystals that are crosslinked may be microcrystals having a cross-section of 100 microns or less. Crosslinked enzyme crystals are sturdy and can withstand harsh conditions and may be used for performing selective chemical reactions in organic or aqueous medium, in an assay, diagnostic kit or biosensor for detecting an analyte, in producing a product such as using crosslinked Peroxidase crystals to produce novel polymers, biotransformations including those used in industrial scale chemical processes and in environmental remediations.