for his work on ribonucleaseandfor their contribution to the understanding of the connection between chemical structure and catalytic activity of the ribonuclease molecule
for their elucidation of the enzymatic mechanism underlying the synthesis of adenosine triphosphateandfor his discovery of an ion-transporting enzyme, Na+, K+ -ATPase
... and was elected Holy Roman Emperor.
He married infanta Isabella, sister of John III of Portugal, who had shortly before married Catherine, Charles's sister.
...