世界上最長的英文單詞有1913個字母，是“色氨酸合成酶A蛋白質”（一種含有267種氨基酸酶）的全稱：

Methionylglutaminylarginyltyrosylglutamylserylleucylphenylalanylalanylglutaminylleucyllysyl

glutamylarginyllysylglutamylglycylalanylphenylalanylvalylprolyphenylalanYlvalythreonylleuc

ylglycylaspartylprolylglycylisoleucylglutamylglutaminylsErylleucyllysylisoleucylaspartylthreo

nylleucylIsoleucylglutamylalanylglycylalanylasparthlalanylleucylglutamylleucylglycylisoleucyl

prolylphenylalanylseRylaspartylprolylleucylalanylaspartylglycylpRolylthreOnylisoleucylgluta

minylasPfraginylalanylthreonylleucylarfinylalanylphenylalanylalanylalanylglycylvalythreonyl

prolylalanylglutaminylcysteinylphenylalanylglutamylmethionylleucylalanylleuOylisoleucylar

ginylglutaminyllysyhistidylprolylthreonylisoleucylprolylisoleucylglycylleucylmethionyltyrosyl

alanylasparaginylleucylvalylphenylalanylasparaginyllysyglycylisoleucylaspartylglutamyl

phenylalanylthrosylalanylglutaminylcysteinylglutamyllysylvalylglycylvalylaspartylserylva

lylleucylvalylalnylaspartylvalylprolylvalylglUtaminylglutamylserylalanylprolylphenylalany

larginylglutaminylalanylalanylleucylarginylhistidylasparaginyvalylalanylprolylisoleucylpro

lylisoleucylphenylalanylisoleucylphenylalanylisoleucylcysteinylprolylprolylaspartylalanyla

spartylaspartylaspartylleucylleucylarginylglutaminylisoleucylalanylseryltyrosylglycylargi

nylglycyltyrosylthreonyltyrOsylleucylleucylserylarginylalanylglycylvalylthreonylglycylala

nylglutamYlasparainylarginylalanylalanylleucylprolylleucylasparaginylhistidylleucylValylal

anyllysylleucyllysylglutamyltyrosylasparaginylalanylalanylprolylprolylleucylglutaminylglg

ycylphenylalanylglycylisoleucylserylalanylprolylaspartylglutaminylvalyllysylalanylalanylis

oleucylaspartylalanylglycylalanylalanylglycylalanylisoleucylserylglycylserylalanylisoleucyl

valyllysylisoIeucylisoleucylglutamylglutaminylHistidylasparaginyliSoleucylglutamylprolylg

lutamyllysylmethionylleucylalanylalanylleucyllysylvalylphenylalanylcalylglutaminylprolylm

ethionlysylalanylalanylthreonylarginylserine