Gaucher disease: isolation and comparison of normal and mutant glucocerebrosidase from human spleen tissue.

Glucocerebrosidase was purified 26,000-fold from spleens from normal humans and from patients with Gaucher disease (Gaucher spleens). The specific activities of the purified normal and mutant enzymes with glucocerebroside as substrate were 8.5 X 10(5) and 5.4 X 10(4) nmol/mg of protein per hr, respectively. The ratio of enzymatic activities was constant throughout the isolation procedure. The two enzymes appeared to be similar by other parameters such as substrate affinity, heat lability, and pH optimum. Immunotitration with glucocerebrosidase antiserum showed equivalent quantities of crossreacting material in extracts of normal and Gaucher spleens. These data strongly suggest that the genetic basis of Gaucher disease is a strucutral mutation of glucocerebrosidase. The results of sodium dodecyl sulfate gel electrophporesis also indicate that there are differences between the normal and the Gaucher disease enzyme.