世界上最长的英文单词有1913个字母，是“色氨酸合成酶A蛋白质”（一种含有267种氨基酸酶）的全称：

Methionylglutaminylarginyltyrosylglutamylserylleucylphenylalanylalanylglutaminylleucyllysyl

glutamylarginyllysylglutamylglycylalanylphenylalanylvalylprolyphenylalanYlvalythreonylleuc

ylglycylaspartylprolylglycylisoleucylglutamylglutaminylsErylleucyllysylisoleucylaspartylthreo

nylleucylIsoleucylglutamylalanylglycylalanylasparthlalanylleucylglutamylleucylglycylisoleucyl

prolylphenylalanylseRylaspartylprolylleucylalanylaspartylglycylpRolylthreOnylisoleucylgluta

minylasPfraginylalanylthreonylleucylarfinylalanylphenylalanylalanylalanylglycylvalythreonyl

prolylalanylglutaminylcysteinylphenylalanylglutamylmethionylleucylalanylleuOylisoleucylar

ginylglutaminyllysyhistidylprolylthreonylisoleucylprolylisoleucylglycylleucylmethionyltyrosyl

alanylasparaginylleucylvalylphenylalanylasparaginyllysyglycylisoleucylaspartylglutamyl

phenylalanylthrosylalanylglutaminylcysteinylglutamyllysylvalylglycylvalylaspartylserylva

lylleucylvalylalnylaspartylvalylprolylvalylglUtaminylglutamylserylalanylprolylphenylalany

larginylglutaminylalanylalanylleucylarginylhistidylasparaginyvalylalanylprolylisoleucylpro

lylisoleucylphenylalanylisoleucylphenylalanylisoleucylcysteinylprolylprolylaspartylalanyla

spartylaspartylaspartylleucylleucylarginylglutaminylisoleucylalanylseryltyrosylglycylargi

nylglycyltyrosylthreonyltyrOsylleucylleucylserylarginylalanylglycylvalylthreonylglycylala

nylglutamYlasparainylarginylalanylalanylleucylprolylleucylasparaginylhistidylleucylValylal

anyllysylleucyllysylglutamyltyrosylasparaginylalanylalanylprolylprolylleucylglutaminylglg

ycylphenylalanylglycylisoleucylserylalanylprolylaspartylglutaminylvalyllysylalanylalanylis

oleucylaspartylalanylglycylalanylalanylglycylalanylisoleucylserylglycylserylalanylisoleucyl

valyllysylisoIeucylisoleucylglutamylglutaminylHistidylasparaginyliSoleucylglutamylprolylg

lutamyllysylmethionylleucylalanylalanylleucyllysylvalylphenylalanylcalylglutaminylprolylm

ethionlysylalanylalanylthreonylarginylserine