Histidine
Essential AA; precursor to histamine; roles in enzyme active sites
Essential AA; precursor to histamine; roles in enzyme active sites
Essential BCAA; energy metabolism; complements leucine/valine
Essential BCAA; mTOR signaling; protein synthesis; cognitive load support
Essential AA; limiting in many cereals; complements legumes
Essential AA; precursor to SAMe via methylation cycle
Essential AA; precursor to tyrosine → catecholamines
Essential AA; structural proteins; mucin production
Serotonin/melatonin precursor; NAD+ pathway substrate; LAT1 transport dynamics
Essential BCAA; supports protein balance and neurotransmitter transport competition