The Purification and Characterization of Soluble Acid Invertase from Coleoptiles of Wheat (Triticum aestivum L. cv. Avalon)

Soluble acid invertase from wheat coleoptiles was purified to electrophoretic homogeneity. A comparison of molecular weight by SDS-PAGE and gel filtration suggested that the enzyme was a monomer of M r 50 000. The enzyme was a glycoprotein and, after chemical deglycosylation, possessed a M r of 48 000. A polyclonal antiserum was raised against the deglycosylated protein. This cross-reacted specifically with acid invertase. A putative precursor of invertase synthesized in a cell-free translation system was detected by SDS-PAGE and fluorography of the immunoprecipitated polypeptides. The distribution of acid invertase in wheat seedling shoots was investigated both by visualizing invertase activity after starch gel electrophoresis and by immunoblotting