The following is an example of a primarily inhibitors amino acid

Glycine is the major inhibitory neurotransmitter in the brainstem and spinal cord, where it paicipates in a variety of motor and sensory functions. Glycine is also present in the forebrain, where it has recently been shown to function as a coagonist at the N-methyl-D-aspaate (NMDA) subtype of glutamate receptor. Ref: guyton and hall textbook of medical physiology 12 edition page number:64,65,66