BRAIN PYRUVATE DEHYDROGENASE: NEUROBIOLOGY AND REGULATI

脑丙酮酸脱氢酶：神经生物学和调节

• 批准号: 3405806
• 负责人: KWAN-FU REX SHEU
• 金额: $ 6.2万
• 依托单位: BURKE REHABILITATION CTR (WHITE PLNS,NY)
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-02-01 至 1989-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3405806
• 关键词: aging; brain metabolism; calcium metabolism; gel electrophoresis; genetic translation; immunochemistry; ionophores; mitochondria; neurochemistry; oxidation; phosphorylation; pyruvate dehydrogenase; radioimmunoassay

The brain energy metabolism is met primarily in mitochondria by oxidative metabolism of pyruvate, which is regulated by pyruvate dehydrogenase complex (PDHC). The PDHC is controlled by a kinase-phosphatase mediated phosphorylation (inactivation) and dephosphorylation (activation) process. Deficits of PDHC have been found in an increasing number of neurological disorders, including Alzheimer's disease. Changes of phosphorylation or activation state of PDHC have also been found to accompany many physiological, pharmacological and behavioral manipulations that give rise to altered brain functions. These changes of PDHC may reflect changes of pyruvate oxidation or Ca sequestration by mitochondria. The molecular events underlying these changes are unclear, however. To this end, the relationship among PDHC regulatory behavior, pyruvate ovidation and mitochondrial Ca sequestration will be delineated in this proposition. The mitochondrial Ca-uptake process is distinct from the effect of intramitochondrially accumulated Ca. The effects of these two processes on pyruvate oxidation and PDHC phosphorylation will be evaluated, using mitochondria treated with ionophore A23187 in Ca-EGTA buffer and mitochonria pre-loaded or depleted with Ca, respectively. With respect to enzyme protein, PDHC may be regulated by phosphorylation at multiple sites and by protein translation during postnatal development. The significance of multiple phosphorylation will be evaluated by comparing the phosphate profile of the phosphopeptide generated by immunoprecipitation and 2-dimensional gel electrophoresis. The enzyme induction mechanism will be tested by radioimmunoassays and in vivo translation assays of the PDHC-peptides. Aging decreases pyruvate oxidation and Ca metabolism. To further test the hypothesis that mitochondrial Ca sequestration is also imparied in aging, the Ca buffering capacity, and Ca uptake and its coupling to pyruvate oxidation and possible link to PDHC phosphorylation will be comared in mitochondria from different age groups.

脑能量代谢主要是通过氧化在线粒体中满足的 丙酮酸的代谢，由丙酮酸脱氢酶调节 复杂（PDHC）。 PDHC由激酶 - 磷酸酶介导的控制 磷酸化（失活）和去磷酸化（激活）过程。 PDHC的缺陷在越来越多的神经系统中发现 疾病，包括阿尔茨海默氏病。 磷酸化或 还发现PDHC的激活状态伴随着许多 产生的生理，药理和行为操纵 改变大脑功能。 PDHC的这些变化可能反映了 线粒体丙酮酸氧化或Ca固换。 分子 但是，这些更改的事件尚不清楚。 为此， PDHC调节行为，丙酮酸排卵和 线粒体Ca固换将在此命题中描述。 线粒体ca摄取过程与 IntochondryChindry积聚的Ca。 这两个过程对 将使用丙酮酸氧化和PDHC磷酸化，并使用PDHC磷酸化。 用离子载体A23187在CA-EGTA缓冲液中处理的线粒体和 线粒体分别预载或用Ca耗尽。 关于酶蛋白，PDHC可以通过磷酸化来调节 多个位点和通过蛋白质翻译在产后发育过程中。 通过比较，将评估多种磷酸化的重要性 由 免疫沉淀和二维凝胶电泳。 酶 诱导机制将通过放射免疫测定和体内测试 PDHC肽的翻译测定法。 衰老会降低丙酮酸氧化和CA代谢。 进一步测试 假设线粒体Ca固醇在衰老中也被忽视 CA缓冲能力以及CA的吸收及其耦合到丙酮酸 氧化和可能与PDHC磷酸化的可能链接将在 来自不同年龄段的线粒体。