The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China.
J Proteomics. 2013 Nov 20;93:93-106. doi: 10.1016/j.jprot.2013.05.038. Epub 2013 Jun 7.
Filterability is an essential quality parameter of barley malt and significantly impacts productive efficiency and quality of beer. In the study, differences of metabolic capability, rather than of initial contents of macromolecules in barleys, were found to be the main reason for malt filterability gap between the widely used cultivars Dan'er and Metcalfe in China. Comparative proteomics based on fluorescent difference gel electrophoresis (DIGE) was employed to quantitatively analyze proteins of four commercial malts belonging to the two cultivars, and 51 cultivar-differential spots were identified to 40 metabolic proteins by MALDI-TOF/TOF mass spectrometry, mainly including hydrolases and pathogen-related proteins. According to their function analysis and abundance comparison between cultivars, filterability-beneficial and -adverse proteins were putatively proposed. Two most remarkable differential proteins, β-amylase and serpin Z7, were further investigated to verify their effects on Dan'er malt filterability. These results provide biological markers for barley breeders and maltsters to improve malt filterability.
To the best of our knowledge, this is the first report of comprehensive investigation of metabolic proteins related to wort filterability of barley malts, and sheds light on clues for filterability improvement. Visible differences in the expression level of metabolic proteins between Dan'er and Metcalfe malts using 2D-DIGE signify a valuable tool for cultivar comparison, illustration of key proteins responsible for filterability and even other qualities of barley malts. And with these explorations on biomarkers of malt filterability and other aspects, there will be higher efficiency and quality of beer brewing, less application of exogenous hydrolases and more expending market for Chinese malting barleys. This article is part of a Special Issue entitled: Translational Plant Proteomics.
过滤性是大麦麦芽的一个重要质量参数，对生产效率和啤酒质量有重大影响。在这项研究中，发现代谢能力的差异，而不是大麦中大分子的初始含量的差异，是在中国广泛使用的品种丹儿和麦特卡夫之间麦芽过滤性能差距的主要原因。基于荧光差异凝胶电泳（DIGE）的比较蛋白质组学被用来定量分析属于这两个品种的四种商业麦芽的蛋白质，通过 MALDI-TOF/TOF 质谱鉴定了 51 个品种差异斑点到 40 个代谢蛋白，主要包括水解酶和与病原体相关的蛋白质。根据它们的功能分析和品种间的丰度比较，提出了过滤性能有益和不利的蛋白质。两个最显著的差异蛋白，β-淀粉酶和丝氨酸蛋白酶抑制剂 Z7，进一步被研究以验证它们对丹儿麦芽过滤性能的影响。这些结果为大麦育种者和麦芽制造者提供了提高麦芽过滤性能的生物标志物。
据我们所知，这是首次全面研究与大麦麦芽麦汁过滤性能相关的代谢蛋白的报告，为提高过滤性能提供了线索。使用 2D-DIGE 观察到丹儿和麦特卡夫麦芽代谢蛋白表达水平的明显差异，这是品种比较、说明负责过滤性能和甚至其他大麦麦芽质量的关键蛋白的有价值的工具。通过对麦芽过滤性能和其他方面的生物标志物的这些探索，将有更高的啤酒酿造效率和质量，减少外源性水解酶的应用和更广阔的中国麦芽大麦市场。本文是一个特刊的一部分，题为：翻译植物蛋白质组学。
