FUNGAL CELL WALL ENZYMOLOGY--(1-3)-B-GLUCAN SYNTHASE

真菌细胞壁酶学--(1-3)-B-葡聚糖合成酶

• 批准号: 3810545
• 负责人: CLAUDE P SELITRENNIKOFF
• 金额: --
• 依托单位: ABBOTT LABORATORIES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3810545
• 关键词: Aspergillus; Blastomyces dermatitidis; Candida albicans; Cryptococcus neoformans; Fungi; Histoplasma; Neurospora; antifungal agents; bioassay; carbohydrate biosynthesis; cell wall; drug screening /evaluation; enzyme induction /repression; enzyme inhibitors; enzyme substrate; gene expression; genetic mapping; glucans; guanine nucleotide binding protein; ligase; molecular cloning; protein purification

Fungi are medically and economically very important, contributing to waste, spoilage and disease. Treatment of human fungal disease, especially in immunodeficient patients, for example those suffering from Acquired Immunodeficiency Syndrome, is hampered by very few clinically useful drugs. Filamentous fungal morphogenesis and growth are the direct result of polysaccharide polymers and other materials being sequentially deposited at each hyphal apex leading to the formation of a mature cell wall. Cell-wall assembly results in a wall containing chitin, beta(1-3) glucan, and other beta- and alpha- linked glucans, proteins and lipids. A key step, perhaps the key step, in fungal cell wall assembly is the synthesis of beta(1-3) glucan and its subsequent incorporation into the cell wall. This proposal has as its aim, the detailed understanding of (1-3) - beta-D-glucan synthase, the enzyme responsible for glucan synthesis. 1.The development of in vitro conditions for the assay of (1-3)-beta-glucan synthase activity of a number of human pathogenic fungi, e.g., Histoplasma capsulatum, Cryptococcus neoformans, Aspergillus nidulans, A. fumigatus, Trichophyton mentagrophytes, Sporothrix schneckii, and Blastomyces dermatitidis. 2.Detailed comparison of (1-3)-beta-glucan synthase activities from the above pathogenic fungi and those of Neurospora crassa and Candida albicans. This will include the determination of various kinetic parameters (substrate, ions, pH optimum, various inhibitors and activators) and detailed product characterization. The GTP-binding regulatory protein will be purified and characterized. 3.Isolation, molecular cloning, and characterization of the gene(s) coding from (1-3)-beta-glucan synthase activity of Neurospora crassa.

真菌在医学和经济上都非常重要，会造成废物， 腐败和疾病。人类真菌病的治疗，特别是在 免疫缺陷患者，例如那些患有获得性 免疫缺陷综合症，是由极少数临床有用的药物阻碍的。 丝状真菌的形态发生和生长是 多糖聚合物和其他材料顺序地沉积在 每个菌丝顶端形成成熟的细胞壁。细胞壁 组装的结果是含有甲壳素、β(1-3)葡聚糖和其他 β和α连接的葡聚糖、蛋白质和脂类。也许是关键的一步 真菌细胞壁组装的关键步骤是β(1-3)的合成 葡聚糖及其随后并入细胞壁。这项建议 以详细了解(1-3)-β-D-葡聚糖为目标 合成酶，负责合成葡聚糖的酶。 1.(1-3)-β-葡聚糖体外检测条件的建立 几种人类致病真菌，如组织胞浆合酶活性的研究 荚膜、新生隐球菌、尼杜拉曲霉、烟曲霉菌、 曼氏毛霉菌、施氏孢子丝菌和芽孢霉菌 皮炎。 (1-3)-β-葡聚糖合成酶活性的详细比较 上述致病真菌及粗枝脉孢菌和白色念珠菌的致病菌。 这将包括确定各种动力学参数。 (底物、离子、最适pH、各种抑制剂和激活剂)和 详细的产品特性。GTP结合调节蛋白 将被提纯和鉴定。 3.S编码基因的分离、分子克隆及鉴定 粗脉孢子菌的(1-3)-β-葡聚糖合成酶活性。