I don't think "reported" fits well here because it seems to imply findings from objective research. The quote, however, talks about a "standard" for research which is a bit more subjective, in my opinion.

I would render the rest of the paragraph as:

As it has been suggested recently, "Lysozyme is the 'standard' protein for studies by physical scientists"[2]. Sometimes, however, researchers claim to be studying lysozyme when in reality they are studying a very different system.

Hope this helps.