The two words that struck me are this chemical compound [1] (quite artificial as a name if you ask me, but apparently considered as a word), and this perfectly real hill name [2]

[1] https://en.wiktionary.org/wiki/Appendix:Protologisms/Long_wo...

[2] https://en.wikipedia.org/wiki/Taumatawhakatangi%C2%ADhangako...

Yes, the Titin example is completely ridiculous. On the one hand, the protein Titin is one of the longest sequences. However you can form a 'word' out of any protein or DNA (or other macromolecue or polymer) this way.

The key problem for me is that you would never refer to any polypeptide this way in a sentence. It would be like referring to a piece of software by concatenating its source code into one long 'word'. Meaningless.