The biosynthesis of α2u-globulin, the major protein in rat urine, was studied in a cell-free system programmed with messenger RNA isolated from rat liver. Analysis of the primary translation product by SDS-polyacrylamide gel electrophoresis showed a molecular weight of approximately 22,000 daltons as compared to 20,000 daltons for the mature form. When translation was carried out in the presence of dog pancreas microsomes, α2u-globulin was cotranslationally processed and sequestered in the microsomal lumen. Automated sequencing to mature α2u and the labeled precursor disclosed the presence of 19 additional amino acids at the amino- terminal end of the primary translation product of the urinary α2u The partial amino acid sequence of this extension was determined.
|Number of pages||4|
|Journal||Journal of Biochemistry|
|State||Published - Oct 1981|