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Updated: Aug 24, 2026

Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy
Published on: September 17, 2017
Conformation of the Z19 prolamin by FTIR, NMR, and SAXS
Lucimara A Forato1, Antonio C Doriguetto, Hannes Fischer
1Embrapa Instrumentação Agropecuária, Rua XV de Novembro, 1452, São Carlos, SP, Brazil.
Abstract:
The alpha zein, the maize storage prolamin, is a mixture of several homologous polypeptides that shows two bands in SDS-PAGE, called Z19 and Z22. The conformation studies carried out by several authors in this mixture are conflicting. To elucidate these inconsistencies, we analyzed the conformation of the Z19 fraction, extracted from BR451 maize variety by Fourier transform infrared spectroscopy, nuclear magnetic resonance, and small-angle X-ray scattering. The infrared results show that Z19 has 46% of alpha helix and 22% of beta sheet. The fast N-H to N-D exchange measured by (1)H NMR spectroscopy showed that Z19 is not a compact structure. The scattering measurements indicated an extended structure with 12 by 130 A. With these data, we have modeled the Z19 structure as a hairpin, composed of helical, sheet, turns, and secondary structures, folded back on itself.
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