01561naa a2200265 a 450000100080000000500110000800800410001910000180006024500610007826000090013952008670014865000110101565300260102665300270105265300090107965300080108865300090109665300080110570000220111370000160113570000230115170000210117470000190119577300810121410286922010-03-08       2004    bl ---       0--  u    #d1 aFORATO, L. A.  aConformation of the Z19 prolamin by FTIR, NMR, and SAXS.  c2004  aThe a 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 oot by several authors in this mixture are conflicting. To elucidate these inconsistencies, we analyzed lhe conformation of lhe 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 a helix and 22% of B sheet. The tast N-H to N-D exchange measured by 1H 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 lhe Z19 structure as a hairpin, composed of helical, sheet, tums, aro secondary structures, folded back on itself.  aZeína  aEstrutura da prlamina  aEstrutura da proteína  aFTIR  aNMR  aSAXS  aZ191 aDORIGUETTO, A. C.1 aFISCHER, H.1 aMASCARENHAS, Y. P.1 aCRAIEVICH, A. F.1 aCOLNAGO, L. A.  tJournal of Agricultural and Food Chemistrygv.22, n.1, p.121-126, jan. 2004.