What is the 189819 letters word?

Exploring the Longest Word

Although pneumonoultramicroscopicsilicovolcanoconiosis holds the title for the longest word in the English dictionary, there is actually a longer term that exists beyond the dictionary confines. The full name for the protein known as 'titin' consists of 189,819 letters. The initial 61 letters of this extensive word are as follows: methionylthreonylthreonylglutaminylarginyltyrosylglutamylsery.