One of the amino acids, called prolene, is not really an amino acid, but imino acid.
有一种称为脯氨酸的氨基酸实际上并不是氨基酸，而是亚氨基酸。
2
Moreover, 19.47% of the grass carp gelatine was found to be composed by iminoacids (Proline and Hydroxyproline).
此外，草鱼鱼皮明胶中的氨基酸组成中，脯氨酸和羟脯氨酸的总含量为19.47%。
3
Except for praline and hydroxyproline which are iminoacids all the amino acids are l-amino acids although d-amino acids do occur in bacterial cell walls and in some antibiotics.