L-alanine.pdb L-arginine.pdb L-asparagine.pdb L-aspartate.pdb L-cysteine.pdb L-glutamate.pdb L-glutamine.pdb glycine.pdb L-histidine.pdb L-isoleucine.pdb L-leucine.pdb L-lysine.pdb L-methionine.pdb L-phenylalanine.pdb L-proline.pdb L-serine.pdb L-threonine.pdb L-tryptophan.pdb L-tyrosine.pdb L-valine.pdb PepBond.pdb ProGFK.pdb ProGTAE.pdb ProGYKLI.pdb enkephalin.pdb 1XY1A.pdb