TY - JOUR
T1 - Biochemical characterization and quantification of the storage protein (secalin) types in rye flour
AU - Gellrich, Claudia
AU - Schieberle, Peter
AU - Wieser, Herbert
PY - 2003
Y1 - 2003
N2 - Kernels of the rye cultivars Danko and Halo were milled into white flour and compared with flour of the wheat cultivar Rektor. Flour proteins were extracted stepwise with a salt solution (albumins-globulins), 60% ethanol (prolamins), and 50% 2-propanol under reducing conditions (glutelins). The quantification by reversed-phase HPLC indicated that the extractable proteins of both rye flours consisted of ≈26% albuminsglobulins, 65% prolamins, and 9% glutelins. Compared with wheat flour, rye flours comprised significantly higher proportions of nonstorage proteins (albumins-globulins) and lower proportions of polymerized storage proteins (glutelins). SDS-PAGE revealed that the prolamin fractions of rye contained all four storage protein types (HMW, γ-75k, ω, and γ-40k secalins), whereas the glutelin fractions contained only HMW and γ-75k secalins. The quantification of secalin types by RP-HPLC showed a close relationship between the two cultivars. The γ-75k secalins contributed nearly half (≈46%) of the total storage proteins, followed by γ-40k secalins (24%) and ω secalins (17%); HMW secalins (≈7%) were minor components, and 6% of eluted proteins were not identified. The amino acid composition of γ-40k secalins corresponded to those of γ-gliadins of wheat, whereas γ-75k secalins were characterized by higher contents of glutamine and proline. Matrix-assisted laser desorption/ionization and time of flight mass spectrometry (MALDI-TOF MS) indicated molecular masses of about 52,000 (γ-75k) and 32,000 (γ-40k), respectively. Nterminal amino acid sequences were homologous with those of wheat γgliadins except for position 5 (asparagine in γ-75k and glutamine in γ-40k secalins) and position 12 (cysteine in γ-75k secalins). The N-terminal amino acid sequences of HMW and ω-secalins were homologous with those of the corresponding protein types of wheat. Gel-permeation HPLC of prolamin fractions revealed that rye flours contained a significantly higher proportion of ethanol-soluble oligomeric proteins than wheat flour.
AB - Kernels of the rye cultivars Danko and Halo were milled into white flour and compared with flour of the wheat cultivar Rektor. Flour proteins were extracted stepwise with a salt solution (albumins-globulins), 60% ethanol (prolamins), and 50% 2-propanol under reducing conditions (glutelins). The quantification by reversed-phase HPLC indicated that the extractable proteins of both rye flours consisted of ≈26% albuminsglobulins, 65% prolamins, and 9% glutelins. Compared with wheat flour, rye flours comprised significantly higher proportions of nonstorage proteins (albumins-globulins) and lower proportions of polymerized storage proteins (glutelins). SDS-PAGE revealed that the prolamin fractions of rye contained all four storage protein types (HMW, γ-75k, ω, and γ-40k secalins), whereas the glutelin fractions contained only HMW and γ-75k secalins. The quantification of secalin types by RP-HPLC showed a close relationship between the two cultivars. The γ-75k secalins contributed nearly half (≈46%) of the total storage proteins, followed by γ-40k secalins (24%) and ω secalins (17%); HMW secalins (≈7%) were minor components, and 6% of eluted proteins were not identified. The amino acid composition of γ-40k secalins corresponded to those of γ-gliadins of wheat, whereas γ-75k secalins were characterized by higher contents of glutamine and proline. Matrix-assisted laser desorption/ionization and time of flight mass spectrometry (MALDI-TOF MS) indicated molecular masses of about 52,000 (γ-75k) and 32,000 (γ-40k), respectively. Nterminal amino acid sequences were homologous with those of wheat γgliadins except for position 5 (asparagine in γ-75k and glutamine in γ-40k secalins) and position 12 (cysteine in γ-75k secalins). The N-terminal amino acid sequences of HMW and ω-secalins were homologous with those of the corresponding protein types of wheat. Gel-permeation HPLC of prolamin fractions revealed that rye flours contained a significantly higher proportion of ethanol-soluble oligomeric proteins than wheat flour.
UR - http://www.scopus.com/inward/record.url?scp=0037242765&partnerID=8YFLogxK
U2 - 10.1094/CCHEM.2003.80.1.102
DO - 10.1094/CCHEM.2003.80.1.102
M3 - Article
AN - SCOPUS:0037242765
SN - 0009-0352
VL - 80
SP - 102
EP - 109
JO - Cereal Chemistry
JF - Cereal Chemistry
IS - 1
ER -