Western blot analyses of wild-type and Gaucher disease acid β-glucosidase from recombinant (A) and natural (B) sources, using case 2 sera. (A) Immunoreactivity of recombinant wild-type and N370S enzymes expressed in the baculovirus system. Similar forms of both recombinant enzymes were detected with serum from case 2. Acid β-glucosidase (lane 1), wild-type enzyme (lanes 2 and 4), N370S enzyme (lanes 3 and 5). (B) Wild-type enzyme from an unaffected individual with normal levels of enzyme activity (lane 1), a Gaucher disease patient who was hemizygous for the N370S allele and a gene deletion (lane 2), the father of the patient in lane 2 who is hemizygous for the normal allele (lane 3), and case 2 who was heterozygous for N370S (lane 4). The three bands present in lanes 1, 3, and 4 correspond to different posttranslational glycosylation stages of acid β-glucosidase.