in experiments with synthetic substrates ( homo-poly-l-amino acids ; alanine , arginine , asparagine , aspartic acid , histidine , leucine , lysine , methionine , phenylalanine , proline , serine and tryptophan ) , only poly-l-arginine was adp-ribosylated by the enzyme .
C0002520
amino acids
C0001898
alanine