Poly(2-acrylamido-2-methyl-1-propanamide) (PAMPA): A neutral, water-soluble synthetic polymer with double-stranded helix conformation

A new synthetic polymer, poly(2-acrylamido-2-methyl-1-propanamide) (PAMPA), is described. It combines the structural features of poly(leucine) and pol y(glutamine), its molecular weight averages 42000 D, and it contains ca. 27 0 residues. A C-13-NMR-tacticity study indicates that it consists of a mixt ure of syndiotactic (38%), heterotactic (48%), and isotactic (17%) polymer. PAMPA has a tendency to self-organize into a coiled-coil double-stranded h elix structure in aqueous solution, as determined by Fourier-transform. inf rared spectroscopy (FT-IR). Molecular modeling of PAMPA shows that the heli x formation is driven by repeated intramolecular H-bonds between nearest-ne ighbor amide groups, and that the structure is further stabilized by hydrop hobic interactions between the two lateral Me groups, PAMPA has a neutral s tructure, is highly water-soluble, and demonstrates temperature stability.