Cloning and sequence analysis of a cDNA for human glycosylasparaginase

We have isolated a full-length cDNA (HPAsn.6) for human placenta glycosylasparaginase using a 221-bp PCR amplified fragment containing rat liver asparaginase gene sequences. The deduced amino acid sequence from the human clone showed sequence identity to both the alpha and beta subunits of the rat enzyme. The human enzyme is encoded as a 34.6 kDa polypeptide that is post-translationally processed to generate two subunits of approx. 19.5 (alpha) and 15 (beta) kDa. A charge enriched region is present at the predicted site where cleavage occurs. Using polyclonal antibodies against the alpha and beta subunits of rat liver asparaginase, we have shown that the human enzyme is similar in structure to the rat enzyme.