Proline (Pro) is one of the components of plant proteins, and can be widespread in the free state in plants.

 English name: proline:
 proline abbreviation: P, Pro
 CAS No. :145 -85-3
 Chemical Formula: C5H9NO2
 Molar mass: 115.13g/mol

 β-pyrrolidinyl-α-carboxylic acid and α-amino acids generally different, there is no free α-amino, it is a sub-α-amino acids, which can be seen as the side chain of α-amino acids replaced by its own amino on the formation of a hydrogen atom and the heterocyclic structure. One common amino acid composition of proteins.

 English name:L- proline; Pro
 Definition: Scientific name: pyrrolidone carboxylic acid. One kind of ring sub-amino acid composition of proteins in the common 20 amino acids in the only sub-amino acids. In the peptide chain has its special role, easy-to-cis-peptide bond formation, is not conducive to the formation of α-helix. Symbols: P.
 Applied science: Biochemistry and Molecular Biology (a subject); amino acids, peptides and proteins (two subjects)