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:1977
卷号:74
期号:4
页码:1358-1362
DOI:10.1073/pnas.74.4.1358
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:Rat liver poly(A)-containing RNA greatly stimulated incorporation of radioactive amino acids into protein when added to a wheat germ in vitro translation system. Approximately 7% of the labeled synthetic product was precipitated following indirect immunoprecipitation with antisera to rat serum albumin. Analysis of this material, and of the cyanogen bromide fragments derived from it, by sodium dodecyl sulfate/polyacrylamide gel electrophoresis revealed that it contained an NH2-terminal extension of about 2500 daltons when compared to rat serum albumin. Automated sequence determination of purified cell-free product labeled with various radioactive amino acids revealed the presence of 18 additional amino acids NH2-terminal to the sequence of rat proalbumin. The partial sequence of this extension was found to be: Met-X-X-X-X-Phe-Leu-Leu-Leu-Leu-Phe-X-X-X-X-X-Phe-X-proalbumin. On the basis of this evidence, the immunoprecipitable cell-free product was designated preproalbumin.