Molecular Analysis of Plant Triacylglycerol Biosynthetic Enzymes

菜籽油是从甘蓝型油菜种子中提取的。除了是一种宝贵的食物来源，菜籽油还是一个大型农业产业的一部分，该产业每年为加拿大经济贡献超过190亿美元。我们的长期目标是提高菜籽油的数量和质量。细胞膜中的蛋白质可以制造菜籽油。这些蛋白质是共同作用产生脂肪的酶，包括三酰甘油(TAG)，这是菜籽油中的一种主要脂肪。在本研究计划中，将对甘蓝型油菜DGAT1这一通向Tag产生途径的最后一种蛋白质进行详细研究，以深入了解其功能。为了准确地了解菜籽油中的主要脂肪TAG是如何产生的，我们需要对制造菜籽油的蛋白质进行分子理解。我们的研究实验室在确定蛋白质的三维结构方面拥有专业知识。结构将使我们能够检查蛋白质中执行产生标签功能的部分(S)。为了大量生产，我们在酵母中表达了油菜籽植物DGAT1蛋白。有了这种蛋白质，我们已经确定它产生的脂肪与油菜籽植物中发现的类似。这种蛋白质将被结晶，以便看到它的三维结构。它的结构确定将需要使用对晶体的X射线曝光。在没有脂肪底物和存在脂肪底物的情况下都会寻找结构。一旦我们能看到与菜籽油生产有关的蛋白质的整体形状和细节，我们就可以设计出能制造更多菜籽油或偏爱不饱和脂肪的蛋白质，这是食品工业所希望的品质。这种更有效的DGAT1蛋白将在油菜籽植物中进行工程设计，将对油菜籽油的生产进行评估。还将确定其他TAG产生酶的结构，以影响油菜籽植物的TAG生产。未来的研究将集中在标签生物合成途径中的其他酶。总体而言，这项研究有可能提高油菜籽中菜籽油的产量，从而提高油菜籽作物的产量。这将对油菜籽作物产业产生重大影响，并为加拿大带来强大的经济优势。该项目还将有助于培训高素质的人员。

Canola oil is made in the seed of the canola plant Brassica napus. Besides being a valuable food source, canola oil is part of a large agricultural industry that contributes to Canada’s economy over 19 billion dollars annually. Our long term goals are to enhance the oil quantity and quality in the canola plant. Proteins located in the membranes of cells make canola oil. These proteins are enzymes that work together to make fats including triacyglycerol (TAG), a predominant fat in canola oil. In this research program, the last protein in pathway toward TAG production, Brassica napus DGAT1, will be studied in detail to gain insight into its function. To understand precisely how TAG, the main fat in canola, is generated, we require a molecular understanding of the protein that makes canola oil. Our research lab has expertise in determining the three-dimensional structure of proteins. A structure will allow us to examine the part(s) of the protein that carries out the function of producing TAG. In order to generate large quantities, we have expressed the canola plant DGAT1 protein in yeast. With this protein, we have determined that it produces fats similar to that found in the canola plant. This protein will be crystallized in order to see its three-dimensional structure. Its structural determination will require the use of X-ray exposure to the crystals. Structures will be sought both in the absence and presence of fat substrates. Once we can see the overall shape and details of the protein involved in canola oil production, we can then design protein that makes more canola oil or has preferences for unsaturated fat, a desired quality in food industry. This more efficient DGAT1 protein will be engineered in the canola plant, which will be assessed for canola oil production. Determining the structure of other TAG producing enzymes will also be conducted with the goals of influencing TAG production in canola plants. Future studies will focus on other enzymes in the TAG biosynthetic pathway. Overall, this study has the potential to improve the canola oil production in the seed of the canola plant, resulting in enhanced yield in the canola crops. This would have a strong effect on the canola crop industry and a strong economic advantage for Canada. This project will also contribute to the training of highly qualified personnel.