Before revision:  Our analysis evidences a quite high fraction of chains with a significant linking , that is with |G'| > 1. We report that Nature promotes configurations with G'<0 and surprisingly, it seems to suppress linking of long proteins.
After revision:  Our analysis evidences a high fraction of chains with a significant linking , that is with |G'| > 1. We report that Nature promotes configurations with G'<0 and surprisingly, it seems to suppress linking of long proteins.