an essential amino acid, C3H3N2CH2CH(NH2)COOH, that is a constituent of proteins and is important as the iron-binding site in hemoglobin. Abbreviation:His; Symbol:H
Main Entry: his·ti·dine Pronunciation: 'his-t&-"dEn Function: noun : a crystalline essential amino acidC6H9N3O2 formed by the hydrolysis of most proteins—abbreviation His