Previous pilot brewing trials have demonstrated that in the absence of a molecular weight (MW) ~12,000 (barley silica eluate (SE) protein), the beer brewed from the malt of these SE -ve varieties formed less haze after accelerated ageing than beers brewed using SE +ve malt varieties. The previously described SE protein was characterised using comparative two-dimensional (2-D) gel electrophoresis immunoblots of barley seed extracts from both SE +ve and SE -ve varieties. The SE protein spot identified was excised and its partial sequence determined, after in-gel cleavage using trypsin and separation of the resulting fragments by reversed-phase high performance liquid chromatography (HPLC). N-terminal sequence analysis of the tryptic peptides from SE +ve and SE -ve varieties identified the SE protein as the barley trypsin inhibitor-CMe precursor (BTI-CMe). The mature BTI-CMe protein is 13.3 kDa and its functional gene is located on chromosome 3H. Cloning of the BTI-CMe protein demonstrated that both SE -ve and SE +ve barley varieties contain a BTI-CMe protein family member that is similar but has a consistently different sequence, primarily in the last 30 amino acid residues of their C-termini.

Item Type:	Refereed Article
Keywords:	barley trypsin inhibitor, malt, protein, beer, haze
Research Division:	Agricultural and Veterinary Sciences
Research Group:	Crop and Pasture Production
Research Field:	Crop and Pasture Biochemistry and Physiology
Objective Division:	Plant Production and Plant Primary Products
Objective Group:	Winter Grains and Oilseeds
Objective Field:	Barley
Author:	Evans, E (Dr Evan Evans)
ID Code:	36221
Year Published:	2007
Funding Support:	Australian Research Council (LP0560329)
Web of Science® Times Cited:	27
Deposited By:	Agricultural Science
Deposited On:	2007-08-01
Last Modified:	2013-01-31
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