Controlled dissolution crosslinked protein crystals

Abstract

Protein crystals crosslinked with a multifunctional crosslinking agent are produced that have the ability to change from an insoluble and stable form to a soluble and active form and to release protein activity at a controlled rate when a change in environment surrounding the crystals occurs. The change in environment may be a change in temperature, pH, chemical composition or shear force acting on the crystals, or a change from a concentrate to a dilute form, or a combination of the changes. The crosslinked protein crystals have a half-life activity under storage conditions greater than at least 2 times that of the soluble protein that is crystallized to form the crystals that are crosslinked, and under conditions of use have an activity similar to the soluble protein. Crosslinking is carried out by reacting a slurry of protein crystals with a multifunctional crosslinking agent such as glutaraldehyde, glyoxal, octanedialdehyde or succinaldehyde using a concentration of crosslinking agent and time for crosslinking that provides crosslinked protein crystals having the desired ability to change due to a change in environment. An epoxide multifunctional crosslinking agent may be used in combination with glutaraldehyde for crosslinking. The crosslinked protein crystals can be used for protein delivery, and may be used in cleaning agents such as detergents, pharmaceutical compositions, vaccines, personal care compositions, veterinary compositions, foods, feeds, diagnostics and decontamination formulations. Proteins used include enzymes and therapeutic or prophylactic proteins such as hormones and antibodies.