Studies on recognition of selenahomolysine by aminoacid transport systems and aminocyl-tRNA synthetase.

In E. coli, Se-3 aminopropylselenocysteine or selenahomolysine (SeHL) does not affect intracellular lysine transport, i.e. it cannot bind E. coli lysine transport systems. In CHO cells it inhibits cationic aminoacid transport system, but only in the presence of Na+, this indicating that it behaves like polar neutral aminoacids. On the other hand, it poorly affects leucine transport both in the presence and in the absence of Na+. SeHL is not activated by aminoacyl-tRNA synthetase preparations from bacterial and mammalian sources, thus it cannot be utilized for protein synthesis.