INTERMOLECULAR CROSS LINKING OF A PROTEIN IN THE CRYSTALLINE STATE: CARBOXYPEPTIDASE-A

Abstract

Single cystals of the enzyme carboxypeptidase-A are catalytically acitve in the crystalline state in the hydrolysis of the substrate carbobenzoxyglycyl-L-phenylalanine. After treatment with an aqueous solution of the bifunctional reagent glutaraldehyde, the crystals become completely insoluble in 1 [image] sodium chloride even in alkaline solution and show a marked increase in mechanical strength. The X-ray diffraction pattern of the native and cross-linked crystals are very similar. The cross-linked crystals show a reduced but still substantial enzymic activity.