pre-pro-plap with other substituents at position 484 ( threonine , proline , methionine , valine , leucine , tyrosine , tryptophan , lysine , glutamic acid , and glutamine ; category ii ) were expressed , as well as the category i amino acids , but there was little or no processing to the pi-g-tailed form , and this latter group exhibited very low enzyme activity .
C0061472
glutamic acid
C0017797
glutamine