Evidence of the glycation and denaturation of LTP1 during the malting and brewing process.
The influence of malting and brewing processes on the chemical and structural modifications occurring on LTP1 was investigated by mass spectrometry and circular dichroism. Proteins were first purified from malt, and samples were collected at various steps of beer processing performed on two barley cultivars. The levels of LTP1 found in malt were not significantly different from the amounts in barley seed. However, in malt, both LTP1b, a post-translational form of LTP1, and a third isoform named LTP1c were isolated. Moreover, both of these proteins were found to be heterogeneously glycated but still exhibited an alpha-helix structure. Both glycated LTP1 and LTP1b were recovered during mashing. It was also shown that glycated LTP1 was unfolded during heat treatment of wort boiling, which is in agreement with the denatured form previously isolated from beer.
Jégou
S
S
Unité de Biochimie et Technologie des Protéines, INRA, B.P. 71627, 44316 Nantes Cedex 03, France.
Douliez
J P
JP
Mollé
D
D
Boivin
P
P
Marion
D
D
D001515:Beer; D002352:Carrier Proteins / Q000737:chemistry* / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D002523:Edible Grain / Q000737:chemistry*; D050556:Fatty Acid-Binding Proteins; D005511:Food Handling; D006031:Glycosylation; D001467:Hordeum / Q000737:chemistry*; D006358:Hot Temperature; D008970:Molecular Weight; D011489:Protein Denaturation; D017433:Protein Structure, Secondary
D002352:Carrier Proteins; D050556:Fatty Acid-Binding Proteins; C422456:Ltp1 protein, barley