[Aggregation of poly-L-proline in aqueous solution].
Infrared spectra were measured for both aqueous (D2O) solution and the solid state of form II poly-L-proline in the amide I region as a function of the temperature. The temperature range includes the region where a precipitation is known to occur. From the analysis of spectra of hydrated films and aqueous solutions at different temperatures one can see that there are some peptide C = O-groups which are bounded with water. From this study it has been concluded that poly-L-proline exists in aggregate form even at temperatures lower that required for precipitation. It is supposed that poly-L-proline forms the aggregates including at least 40--50 polypeptide chains with hexagonal packing. At heating crystallisation of such aggregates occurred and it causes precipitation of poly-L-proline II.
D007700:Kinetics; D046911:Macromolecular Substances; D010455:Peptides; D011392:Proline / Q000031:analogs & derivatives; D012996:Solutions; D013055:Spectrophotometry, Infrared; D013696:Temperature; D014867:Water
D046911:Macromolecular Substances; D010455:Peptides; D012996:Solutions; D014867:Water; C011083:polyproline; D011392:Proline
Agregatsiia poli-L-prolina v vodnom rastvore.