INVITRO SYNTHESIS AND PROCESSING OF WHEAT ALPHA-AMYLASE - TRANSLATION OF GIBBERELLIC ACID-INDUCED WHEAT ALEURONE LAYER RNA BY WHEAT-GERM AND XENOPUS-LAEVIS OOCYTE SYSTEMS

A 41,500-dalton protein was made which was identified as .alpha.-amylase by immunoprecipitation with rabbit anti-.alpha.-amylase antiserum raised against the purified wheat protein and by its co-migration with authentic .alpha.-amylase on sodium dodecyl sulfate polyacrylamide gels. Synthesis of .alpha.-amylase was dependent upon injection of RNA extract from GA-induced aleurone layers from wheat. The amount of .alpha.-amylase produced was proportional to the amount of RNA injected and reached a plateau within 4 h after injection. When the same RNA was translated in a wheat germ cell-free translation system, a 43,000-dalton protein was produced. Addition of dog pancreas microsomal membranes to the wheat germ translation system resulted in processing of the .alpha.-amylase protein to a form which co-migrated with authentic .alpha.-amylase purified from malted wheat and with the protein synthesized in oocytes.