Insulin

The three models are of insulin.

https://en.wikipedia.org/wiki/Insulin

The structure was taken from the protein database:
https://www.rcsb.org/structure/3ins
In this particular case, the data results from a joint neutron and X-ray refinement. The paper can be found here:
A. Wlodawer, H. Savage, G. Dodson, Acta Crystallogr B 1989, 45 (Pt 1), 99–107.
http://scripts.iucr.org/cgi-bin/paper?S0108768188011012

The STLs were made with VDM.

The file endings 07, 08, and 10 denote the factor that was used on the van der Waals radius, meaning 0.7, 0.8 or 1.0. At a factor of 1.0 you will have the most realistic view, but it is very bulky. At 0.7 the structure becomes more apparent.

The print shown was made through selective laser sintering, no supports were required. You will need supports for fused deposition modeling of course. The glucose molecule shown for size comparison can be found here:
https://www.thingiverse.com/thing:4791044

Scale to desired size. Let me know if