Since we're fighting in chemical names
Titin with 189,819
Bless my chem teacher (I hated them)
Methionyltreonylthreonylglutaminylalrylglycylphenylalanylprolylvalylprolyylglycylarginylalanyllysylleucylthreonylglutamylleucylleucylvalyllysylalanutaminylvalylarginylvalylthreonylglycglutaminylglutamylglycylaspartylleucyylthreonylserylthreonylalanylgl......