The first demonstration of isomorphous replacement in protein crystallography. This was a key step in determination of the structure of large biological molecules. Harittai, "On the origins of isomorphous replacement in protein crystallography," Structural Chemistry, 33, 2022, 635-639.

Digital facsimile from royalsocietypublishing.org at this link.

Solution of the structure of hemoglobin, a protein with 10,000 atoms. This was the culmination of 30 years of research by Perutz.

Order of authorship in the original paper: Perutz, Rossmann, Culis, Muirhead, Will, North.

In 1962 Perutz shared the Nobel Prize in Chemistry with his student John Cowdery Kendrew "for their studies of the structures of globular proteins."

Thirty years after beginning his research on hemoglobin Perutz solved the Fourier synthesis of hemoglobin at 2.8Å (high resolution) and built an atomic model of the molecule. With Hilary Muirhead, J. M. Cox & L. C. G. Goaman.

Perutz opened up "the field of 'molecular pathology,' relating a structural abnormality to a disease" (Aaron Klug, "Max Perutz 1914-2002," Science 295 ([2002] 2383). Specifically Perutz showed that hemoglobin molecules collapse into a sickle shape in the blood disorder sickle-cell anemia. 

Reprints landmark papers with commentary by Perutz.