has role L-alpha-amino acid D-proline L-proline Pyrrolidine in which the pro-S hydrogen at position 2 is substituted by a carboxylic acid group. L-Proline is the only one of the twenty DNA-encoded amino acids which has a secondary amino group alpha to the carboxyl group. It is an essential component of collagen and is important for proper functioning of joints and tendons. It also helps maintain and strengthen heart muscles. CHEBI:13154 CHEBI:45040 prolina HMDB:HMDB0000162 (S)-pyrrolidine-2-carboxylic acid CHEBI:21373 DrugBank:DB00172 MetaCyc:PRO L-Proline L-pyrrolidine-2-carboxylic acid CHEBI:184637 L-alpha-pyrrolidinecarboxylic acid (-)-(S)-proline proline Wikipedia:L-proline CHEBI:42067 CHEBI:6286 (S)-2-pyrrolidinecarboxylic acid L-proline PROLINE (2S)-pyrrolidine-2-carboxylic acid prolinum L-Prolin PDBeChem:PRO KNApSAcK:C00001388 CHEBI:45100 L-(-)-proline CHEBI:17203 (-)-2-pyrrolidinecarboxylic acid P 2-Pyrrolidinecarboxylic acid KEGG:D00035 (-)-proline KEGG:C00148 (S)-2-carboxypyrrolidine CHEBI:45159 compatible osmolytes glutamine family amino acid proline micronutrient L-prolinate L-prolinium nutraceutical L-proline zwitterion mouse metabolite Saccharomyces cerevisiae metabolite Escherichia coli metabolite proteinogenic amino acid algal metabolite