Studies on isolated islets of Langerhans (Brookmann bodies) of teleost fishes II. Evidence for insulin biosynthesis in vitro

摘要: Abstract Isolated islet tissue of toadfish ( Opsanus tau ) has been incubated in vitro and the incorporation radioactive substrates into protein studied. Using 14 C-labeled substrates, high specific activities were found insulin which was purified from crude extracts by a combination paper chromatography, isoelectric precipitations cellulose adsorption. The highest activity labeled with C achieved these studies 5.7·10 5 counts/min/mg. biologic this preparation 7.7 units/mg. [ C]isoleucine as substrate, preferential labeling A chain could be demonstrated, would expected absence isoleucine B chain.