A de novo 140-amino acid residue polypeptide YE8 with a regular 16 amino acid repeat sequence, (GA)₃GY(GA)₃GE exhibits remarkable folding properties and, as well, forms fibrillar structures. Deep UV Resonance Raman spectroscopy was employed to investigate the polypeptide structural transformations during the folding and fibrillation process. We found that the YE8 polypeptide shows all the properties of a typical amyloid fibril-forming protein including a pronounced directing or templating effect. A strong concentration dependence for b-sheet formation correlates with the lag time. However despite the ability of repetitive unit GAGAGAG to form highly regular b-sheet structure, there was no evidence for intramolecular promoting of folding by YE8 polypeptide. AFM, TEM, CD and fluorescence spectroscopy were also used in this work.