Cloning a cDNA for the lysosomal alpha-glucosidase

Messenger RNA was isolated from monkey testes and size-fractionated on sucrose gradients. In vitro translation of these mRNA fractions resulted in nascent, labeled alpha-glucosidase that could be precipitated with anti human alpha-glucosidase antiserum. A cDNA library was constructed from the most enriched fraction. The library was screened with cDNA made from mRNA obtained from immunoselected polysomes. Five cross-hybridizing clones were isolated and identified by their selection of alpha-glucosidase mRNA, as shown by hybrid released translation and further by their ability to hybridize with DNA from human chromosome 17, on which the gene coding for acid alpha-glucosidase is located.