Quinoproteins: Characterization and Mechanism

醌蛋白：表征和机制

• 批准号: 9020499
• 负责人: Joseph Villafranca
• 金额: $ 17.6万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-04-01 至 1994-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9020499&HistoricalAwards=false
• 关键词: Quinoproteins; Characterization; Mechanism

The aims of this proposal are to employ biochemical and biophysical methods to further characterize a class of cofactor-containing enzymes called quinoproteins. The research will focus on the mammalian quinoproteins, plasma monoamine oxidase, kidney diamine oxidase and lysyl oxidase. All of these enzymes had been thought to contain the bacterial cofactor, pyrroloquinoline quinone, PQQ, but this conclusion is now in doubt. The objectives of this proposal are 1) to characterize the active site cofactor-containing peptides of diamine oxidase and lysyl oxidase. It is possible that these enzymes have the same cofactor as plasma monoamine oxidase, i.e., 6-hydroxydopa; 2) to clone the genes and develop an expression system for plasma monoamine oxidase and kidney diamine oxidase; 3) to characterize the proximity of the Cu2+ and cofactor sites of all three enzymes using a variety of biophysical methods; and 4) to initiate an investigation of the biosynthetic origin of 6-hydroxydopa. These studies will provide a clear understanding of the mechanistic and structural features of these metalloquinoproteins and lead to a consensus concerning the nature of the carbonyl cofactor in quinoproteins of mammalian origin.

这项建议的目的是使用生化和生物物理方法来进一步表征一类称为藜麦蛋白的含有辅因子的酶。这项研究将集中在哺乳动物的藜麦蛋白、血浆单胺氧化酶、肾脏二胺氧化酶和赖氨酸氧化酶。所有这些酶都被认为含有细菌辅助因子--吡咯喹啉醌，PQQ，但这一结论现在受到了质疑。本提案的目的是：1)鉴定二胺氧化酶和赖氨酰氧化酶的活性部位辅因子多肽。这些酶可能具有与血浆单胺氧化酶相同的辅因子，即6-羟基多巴，2)克隆这些基因，并建立血浆单胺氧化酶和肾脏二胺氧化酶的表达系统，3)用各种生物物理方法表征这三种酶的Cu2+和辅因子位点的接近程度；4)研究6-羟基多巴的生物合成来源。这些研究将提供对这些金属藜麦蛋白的机制和结构特征的清楚了解，并导致关于哺乳动物来源的藜麦蛋白中的羰基辅助因子的性质的共识。