Conformational analysis of the repeated sequence of glutelin-2, a maize storage protein

✍ Scribed by Miquel Pons; Miguel Feliz; Carles Celma; Ernest Giralt

• Publisher: John Wiley and Sons
• Year: 1987
• Tongue: English
• Weight: 494 KB
• Volume: 25
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1260250504

✦ Synopsis

The presence of repeated proline-rich sequences constitutes a common trend in several cereal storage proteins. The protected hexapeptide Boc-Val-His-Leu-Pro-Pro-Pro-OH (l), with the sequence of the repeated region of glutelin-2 (28 kD) from maize, has been studied by proton and 13C NMR in DzO, DMSO-d6, CDCI, and CDC1,-CD30D at different temperatures. Spectra were assigned mainly by using 2D correlation techniques. The spectra in D,O and DMSO-d6 suggest that peptide 1 has a random coil, all-trans conformation. In CDCI, 1 presents a folded conformation, stabilized by hydrogen bonds, with one of the methyl groups of the valine residue situated over the histidine ring. In CDCI3-CD30D 1 is present as a mixture of different conformations. The spectral data are discussed taking as a reference the known conformation of polyproline.

KEY WORDS Polyproline glutelin-2 storage proteins conformational analysis repeated peptide 2D NMR.