Amos Maritan
SISSA Trieste
Emergenza di strutture secondarie in biopolimeri da principi varizionali
Folded states of biopolymers and proteins are not ``typical'' random
conformations of compact polymers below the $\theta$-transition. The native
states of water soluble globular proteins are compact in order to bury
hydrophobic residues. Secondary motifs such as $\alpha$ helices are commonly
found in native state of proteins. Evolutionary forces have resulted in
a selection not only in space of amino acids sequences but also in structure
space to make proteins able to fold reproducibly and rapidly. $\alpha$
helices are shown to emerge rather naturally from a dynamical variational
principle for selection in conformation space based on the requirement
that the backbone of the native state of biological viable polymers be
rapidly accessible from the unfolded phase. Other recent developments will
be presented on the emergence of secondary structures in ``optimal'' compact
conformations of polymers. The role of the native state topology of proteins
during the folding process has important applications for antiviral drug
resistance.