an S-substituted L-cysteine => a thiol + 2-aminoprop-2-enoate
an s-substituted l-cysteine => a thiol + 2-aminoprop-2-enoate
an S-substituted L-cysteine => a thiol + 2-aminoprop-2-enoate
an s-substituted l-cysteine => a thiol + 2-aminoprop-2-enoate