Dear Admas, this has to do with PCN (protein contact networks) in which Cytoscape is a very common software tool of analysis, see:

Article GIANT: A cytoscape plugin for modular networks

in the case of spike protein of SARS COV2:

Article The discovery of a putative allosteric site in SARS-CoV-2 sp...

while this is a more genral introduction to PCN:

Article Protein Contact Networks: An Emerging Paradigm in Chemistry

Dear Alessandro,

Thank you so much for the insight and all the resources you have shared. It is quiet helpful!

Admas

I hope it could be of help...