The molecule is the L-enantiomer of selenocysteine. It has a role as a human metabolite. It is a L-alpha-amino acid, a selenocysteine, a proteinogenic amino acid and a L-alanine derivative. It is a conjugate base of a L-selenocysteinium. It is a conjugate acid of a L-selenocysteinate(1-). It is an enantiomer of a D-selenocysteine. It is a tautomer of a L-selenocysteine zwitterion.