Histidine

#Biochemistry

O=C([C@H](/docs/cc1-cnc-n1)N)O

(His) H

Properties:

• Basic
  • Functional group is an imidazole
• Anionic histidine can tautomerize to form the anionic $\displaystyle \tau$ tautomer as opposed to the usually seen anionic $\displaystyle \pi$ tautomer (ACS article):

O=C([C@H](/docs/cc1-cn-cn1)N)O