Data presented in the CECAM Conference: BioMolecular Electronics -- BIOMOLECTRO ( link: https://www.cecam.org/workshop-details/246). Here we discuss how point mutations can result in abrupt changes of the electron transfer properties of proteins, and the findings are rationalized using a combination of Ab-Initio and Molecular dynamics simulations. This is intended to provide an overview of the results published in several peer-reviewed freely available papers: J. Am. Chem. Soc. 139, 15337-15346 (2017) [DOI: 10.1021/jacs.7b06130] Phys. Chem. Chem. Phys. 20, 30392 (2018) [DOI:10.1039/C8CP06862C] Biomolecules 9, 611 (2019) [DOI:10.3390/biom9100611] Biomolecules 9, 506 (2019) [DOI: 10.3390/biom9090506]