An exceptional series of phase transitions in hydrophobic amino acids with linear side chains.

ABSTRACT: The solid-state phase transitions and intermediate structures of S-2-amino-butanoic acid (l-2-aminobutyric acid), S-2-aminopentanoic acid (l-norvaline), S-2-aminohexanoic acid (l-norleucine) and l-methionine between 100 and 470 K, identified by differential scanning calorimetry, have been characterized in a comprehensive single-crystal X-ray diffraction investigation. Unlike other enantiomeric amino acids investigated until now, this group featuring linear side chains displays up to five distinct phases. The multiple transitions between them involve a number of different processes: alteration of the hydrogen-bond pattern, to our knowledge the first example of this observed for an amino acid, sliding of molecular bilayers, seen previously only for racemates and quasirac

SUBMITTER: Gorbitz CH 

PROVIDER: S-EPMC5391856 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature