| Summary: | 碩士 === 國立臺灣大學 === 農藝學研究所 === 92 === In the present study, we analyzed starch granule-associated proteins
by using proteomics from fifteen kinds of Scotland barley varieties which were classified into four levels of malt quality. For the best 8 varieties of malts, they were varieties for brewing by the Scotland Whisky factories in the present time. Besides, the old varieties for brewing, the varieties
with bad malt characteristic and the varieties for the feed were also used.
First, we studied on those four kinds of barley varieties by regular one dimension SDS-PAGE on starch granule surface and integral proteins. The results indicated starch granule surface proteins were mainly between 30-45 kDa while integral proteins distributed between 25-100 kDa with four main protein bands, i.e. the 94 kDa, 86 kDa, 74 kDa and 62 kDa proteins. For further analysis, these proteins were analyzed by two-dimensional electrophoresis and we divided the protein spots into five regions for the convinience of detail analysis. The difference of these varieties at region 1 which contained starch synthase I (SS I) and granule-bound starch synthase I (GBSS I) were not very obvious. The region 2 located on the area with molecular weight about 50 kDa and between pH5~6.5. Most of these varieties contained number 21, 22 and 23 spots. It was hypothesized that the difference of the proteins in this area should not be essential proteins for brewing characteristics. The region 3 proteins were mostly serpin Z4 and the proteins in the non-brewing varieties contained lower amount of serpin Z4. Thus, there were positive relationship between the amount of serpin Z4 and the characteristic of the barley brewing ability. The proteins in region 4 were mainly hordein B, one kind of the barley storage proteins. The feed varieties gave different patterns in this area which might differentiate the varieties for feeding from other varieties. The proteins in region 5 would also showed positive correlation with the characteristic for brewing ability, however, we could not recognize the proteins identity in this region yet. Further analysis should be perform in order to understand the relationship between these proteins and brewing ability.
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