There are five principal objectives of the contract. The first is to prepare glucocerebrosidase in as high a degree of purity as possible in order to examine its clinical effectiveness in enzyme replacement trials in patients with Gaucher's disease. The second is to develop strategies to target the enzyme to specific cells in the body in which the toxic accumulation of lipid (glucocerebroside) occurs in these patients. The third is to develop methods to extend the half-life of the enzyme in the organs of recipients from the current estimate of eight hours to a much protracted interval in order to enhance the catabolism of accumulated glucocerebroside beyond that presently possible. The fourth is to develop techniques to ensure the maximum delivery of the exogenous enzyme to the intracellular site of lipid accumulation. The fifth is to produce antibodies to homogeneous glucocerebrosidase for use as diagnostic probes and to facilitate the isolation of the human glucocerebrosidase gene.