JBC, Vol. 252, Issue 4, 1272-1278, Feb, 1977
Translation of albumin messenger RNA in a cell-free protein-synthesizing system derived from wheat germ
T. P. Tse and J. M. Taylor
Purified rat liver albumin mRNA directed the synthesis of albumin in a
mRNA-dependent cell-free protein-synthesizing system derived from wheat
germ extracts. The [3H]leucine-labeled in vitro translation product reacted
with antibodies specific for albumin and co-migrated with authentic
14C-labeled serum albumin during gel electrophoresis in the presence or
absence of sodium dodecyl sufate. Higher concentrations of potassium and
magnesium ions were required for the translation of albumin mRNA than for
total liver mRNAs. These requirements were consistent for the purified
albumin as well as when it was a component in the liver mRNA mixture. At
the higher potassium or magnesium concentrations, only intact albumin
molecules were synthesized, whereas lower concentrations of these ions
caused the production of antibody-reactive fragments. These fragments were
apparently the result of premature termination of peptide synthesis and not
due to endogenous proteolytic activity.