STRUCTURE OF PROTEIN-BOUND BILE PIGMENTS

具有共价结合血红素或线性四吡咯（胆汁）的蛋白质 色素）辅基普遍存在于生物体中。 这些蛋白质在电子传递、光化学和许多其他方面发挥作用。 其他角色。 本研究旨在确定 蛋白质结合的结构、立体化学和生物合成 特异性聚焦于胆绿素衍生胆色素假体的四吡咯 藻胆蛋白的组。 带有四吡咯的小肽 辅基将以纯的形式分离，并且它们的结构和 通过技术的组合确定立体化学，包括1H NMR、快原子轰击质谱、圆二色性，以及， 在可能的情况下，通过与参比化合物进行比较， 通过用已知晶体降解带有四吡咯的蛋白质 结构或合成。 一种灵敏的体外荧光检测方法 已经开发了用于测量线性添加 四吡咯到载脂藻胆蛋白，并将用于 前体化合物及其合成中涉及的酶的检测 和与多肽的连接。 分子遗传学方法 还设计了这些酶的鉴定。

Proteins with covalently bound heme or linear tetrapyrrole (bile pigment) prosthetic groups are present universally in having organisms. These proteins function in electron transport, photochemistry, and many other roles. This research is directed at the determination of the structure, stereochemistry, and biosynthesis of protein-bound tetrapyrroles with specific focus on biliverdin-derived bilin prosthetic groups of the phycobiliproteins. Small peptides bearing tetrapyrrole prosthetic groups will be isolated in pure form and their structure and stereochemistry determined by a combination of techniques, including 1H NMR, fast atom bombardment mass spectrometry, circular dichroism, and, where possible, by comparison with reference compounds, either derived by degradation of tetrapyrrole-bearing proteins with known crystal structures, or by synthesis. A sensitive in vitro fluorescence assay has been developed for the measurement of the addition of linear tetrapyrroles to apophycobiliproteins and will be utilized for the detection of precursor compounds and enzymes involved in their synthesis and attachment to the polypeptides. Molecular genetic approaches to the identification of such enzymes have also been devised.