[Analysis of food and feed by partial sequences of characteristic protein components (carrier peptides). 1. Isolation and structural determination of wheat-specific peptides from chymotryptic hydrolysates of gliadin].
Gliadins from wheat flour were extracted with 70% aqueous ethanol and hydrolyzed with alpha-chymotrypsin. Eight peptides, which seemed adequate as specific indicators for wheat ('Leitpeptide'), were isolated from the partial hydrolysate by RP-HPLC and analyzed for their amino acid sequences. Six of them were attributed to gliadin sequences already described in the literature, whereas two peptides represented novel sequence variations. Parallel investigations on the corresponding partial hydrolysates of prolamins from rye, barley, oats and maize showed that the isolated peptides were specific for wheat. A search in the protein data bank MIPS X (as of January 23 rd, 1990) did not produce any identical sequence. The 'Leitpeptide' allows the sensitive and specific recognition of wheat in complex and heated systems by RP-HPLC. They could be used also as the basis for immunochemical tests which would be convenient in routine analysis.
Nägele
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Institut für Lebensmittelchemie der TU München, Bundesrepublik Deutschland.
Belitz
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HD
Wieser
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D000595:Amino Acid Sequence; D000821:Animal Feed / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D002918:Chymotrypsin / Q000378:metabolism; D002523:Edible Grain; D005433:Flour; D005504:Food Analysis; D005903:Gliadin / Q000737:chemistry / Q000302:isolation & purification*; D001467:Hordeum; D006868:Hydrolysis; D008969:Molecular Sequence Data; D010455:Peptides / Q000032:analysis* / Q000737:chemistry; D010940:Plant Proteins / Q000737:chemistry; D055315:Prolamins; D012434:Secale; D014908:Triticum; D003313:Zea mays
D010455:Peptides; D010940:Plant Proteins; D055315:Prolamins; D005903:Gliadin; D002918:Chymotrypsin
Analyse von Lebensmitteln und Futtermitteln über Partialsequenzen charakteristischer Proteinkomponenten (Leitpeptide). 1. Mitteilung: Isolierung und Strukturaufklärung von weizenspezifischen Peptiden aus chymotryptischen Gliadinhydrolysaten.