부산대학교 도서관

A strain of Chlorella vulgaris, after having been induced to resist the growth uncoupling effect of selenomethionine (and which maintained that resistance after removal of the analogue), absorbed l-[35S]methionine much more slowly than did unadapted cells. Although uptake was slower, a greater proportion of the absorbed 35S was incorporated into protein of the induced cells. [35]Sulfate absorption and conversion to protein, however, were the same in both strains. Sulfur starvation, a treatment that causes adapted cells to deadapt and regain their sensitivity to selenomethionine, restored permeability to methionine in the adapted cells. The uptake of methionine was inhibited by dinitrophenol and appears, therefore, to be an active, energy-requiring process. Repression of a methionine-absorbing system, perhaps a “permease”, is held responsible for the induced resistance to selenomethionine.