BIOTINIDASE AND ITS ROLE IN BIOTIN METABOLISM

生物素酶及其在生物素代谢中的作用

• 批准号: 2889230
• 负责人: BARRY WOLF
• 金额: $ 22.19万
• 依托单位: VIRGINIA COMMONWEALTH UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-08-01 至 2001-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2889230
• 关键词: acidity /alkalinity; adolescence (12-20); amidohydrolases; biotin; blood proteins; chemical binding; child (0-11); clinical research; enzyme activity; enzyme biosynthesis; enzyme deficiency; enzyme mechanism; ethanolamines; fibroblasts; human subject; human tissue; immunocytochemistry; laboratory rabbit; lymphoblast; lysine; nutrition related tag; propionyl coA carboxylase; protein degradation; secretion; vitamin metabolism

DESCRIPTION: Biotinidase is the enzyme responsible for the recycling of the vitamin biotin from biocytin (epsilon-biotinyl-L-lysine) and biotinyl-peptides formed by the proteolytic degradation of biotin-dependent carboxylases. Biotinidase deficiency is the primary enzymatic defect in an inherited form of biotin-responsive, late-onset multiple carboxylase deficiency. The applicant has shown that in addition to its cleavage activity, biotinidase transfers biotin to various nucleophilic acceptors, including specific serum proteins, when incubated with biocytin at neutral to alkaline pH. His research group thus far has identified histones in this group of biotinylated protein in serum. In the proposed research, additional biotinylated proteins and small molecules will be identified in serum and in cells and tissues. It will also be determined if biotinidase biotinylates and/or removes biotin from biotin-dependent carboxylases and if it plays a role in transporting biotin into cells. To better understand these functions and the metabolism of biotinidase, the applicant plans to study the biochemistry and cell biology of the enzyme in normal serum and tissues, in various tumor cells, and in biotinidase-deficient states. The subcellular localization of biotinidase in normal and clinically relevant cultured cells and tissues will be determined using immunocytochemical techniques. The characteristics of uptake, turnover, and secretion of biotinidase by these cells will also be determined. Similar studies will also be performed using fibroblasts and lymphoblasts of individuals with biotinidase deficiency. The results will be compared to those of normal cells and will be correlated with the biochemical characteristics of biotinidase in sera of biotinidase-deficient individuals and with their molecular defects. These results will have implications for the prognosis and treatment of biotinidase-deficient children. In addition, the proposed research will provide a better understanding of the role of biotinidase in biotin metabolism and will be a paradigm for understanding the metabolism of other vitamins.

描述：生物素酶是一种负责回收生物素的酶。 来自生物胞素的维生素生物素（ε-生物素基-L-赖氨酸）和 生物素依赖性蛋白水解降解形成的生物素基肽 羧化酶 生物素酶缺乏是一种主要的酶缺陷， 遗传性生物素反应性迟发型多羧化酶 缺陷 申请人已经表明，除了其裂解之外， 活性，生物素酶将生物素转移到各种亲核受体， 包括特异性血清蛋白，当与生物胞素在中性 到目前为止，他的研究小组已经确定了这一过程中的组蛋白。 血清中的生物素化蛋白。 在拟议的研究中， 其他生物素化的蛋白质和小分子将在 血清和细胞及组织中。 还将确定生物素酶是否 生物素化和/或从生物素依赖性羧化酶中除去生物素， 它在将生物素转运到细胞中方面发挥作用。 更好地了解 这些功能和生物素酶的代谢，申请人计划 研究正常血清中酶的生物化学和细胞生物学， 组织、各种肿瘤细胞和生物素酶缺乏状态。 的 生物素酶在正常和临床相关组织中亚细胞定位 培养的细胞和组织将使用免疫细胞化学 技术. 的摄取，周转和分泌的特点， 还将测定这些细胞的生物素酶。 类似的研究将 也可以使用患有以下疾病的个体的成纤维细胞和淋巴母细胞进行 生物素酶缺乏 结果将与正常对照组进行比较。 细胞，并将与生物化学特性的 生物素酶缺乏个体的血清中的生物素酶及其 分子缺陷 这些结果将对预后产生影响 和治疗缺乏生物素酶的儿童。 此外，拟议的 研究将提供一个更好的了解生物素酶的作用， 生物素代谢，将是一个范例，了解代谢的 其他维生素