Before revision:  The exchanging of identical structural elements  typical of domain-swapped proteins make them suitable candidates to validate this possibility . Here we analyze 110 non redundant domain-swapped dimers filtered from the 3Dswap and Proswap databases, by keeping only structures not affected by the presence of holes along the main backbone chain.
After revision:  The exchanging of identical structural elements typical of domain-swapped proteins make them suitable candidates to validate the possibility that mutual entanglement between chains may play a similar role for protein complexes. We suggest that such entanglement is captured by the linking number. This represents, for two closed curves, the number of times that each curve winds around the other. We show that closing the curves is not necessary, as a novel parameter G', termed Gaussian entanglement, is strongly correlated with the linking number. Based on 110 non redundant domain-swapped dimers filtered from the 3Dswap and Proswap databases, by keeping only structures not affected by the presence of holes along the main backbone chain.