期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1979
卷号：76
期号：12
页码：6448-6452
DOI：10.1073/pnas.76.12.6448
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Xenopus oocytes injected with zein mRNAs efficiently synthesized maize storage proteins for prolonged periods. Under optimal conditions, zein was synthesized at 3 ng/hr and represented approximately 10% of the total protein synthesized in the oocyte. The mRNA from the normal maize inbred line directed synthesis of all the major zein components; however, products of mRNA from the opaque-2 mutant did not contain the largest zein component. Zein proteins synthesized in the oocyte were 2000 daltons smaller than proteins synthesized by cell-free translation of mRNAs in the wheat germ and reticulocyte systems. This result, which suggested that the oocyte processed prezein polypeptides into native zein proteins, was confirmed by amino-terminal sequence analysis of zein proteins from the oocytes. Cyanogen bromide cleavage of translation products from oocytes and the wheat germ system confirmed the existence of several proteins within each of the major zein components. However, we were unable to detect the presence of signal sequences on zein peptides by this technique.
