Structure and function of cytochrome b561

描述(申请人提供)：肾上腺抗坏血酸依赖细胞色素(Cyt.)B561是一种跨膜电子转运体，是合成儿茶酚胺和一些多肽激素所必需的，是一种扩张型的、特征不充分的细胞色素T的原型。B561蛋白家族；其他哺乳动物家族成员与肠道铁运输和肿瘤抑制有关。我们的总体目标是研究肾上腺b561的作用机制，并利用有关该细胞色素的信息来了解其他b561家族成员的结构和功能。本项目的具体目标是：1)明确肾上腺细胞的结构核心。B561，确定其与膜双层的关系，并评价其在哺乳动物Cyt中的共性。B561家族成员；2)肾上腺细胞相互作用的特征。B561及其天然还原剂抗坏血酸和其天然氧化剂半氢抗坏血酸；以及3)决定通过肾上腺细胞的电子流动路径。B561及其法规。计划对天然哺乳动物蛋白、重组野生型和突变型肾上腺细胞色素和其他哺乳动物细胞色素进行实验。我们开发的原核和真核系统中的B561家族成员。我们将利用生化和生物物理技术对这些重组蛋白和纯化的内源性肾上腺细胞色素b561的拓扑、结构和动力学性质进行表征。了解肾上腺细胞如何。B561的功能是了解肾上腺素和去甲肾上腺素以及人类某些肽激素的生理学和病理学的基本部分。明确肾上腺细胞之间的异同。B561和最近发现的人类细胞。B561家族成员将加速表征较新的细胞色素T的生理和病理作用。B561号。

DESCRIPTION (provided by applicant): Adrenal ascorbate-dependent cytochrome (cyt.) b561 is a transmembrane electron transporter required for synthesis of catecholamine and some peptide hormone and is the prototype of an expanding and insufficiently characterized cyt. b561 protein family; other mammalian family members have been linked to intestinal iron transport and tumor suppression. Our overall goal is to characterize the mechanism of adrenal b561 and to use information about this cytochrome to understand the structure and function of other b561 family members. The specific aims of this project are: 1) Define the structural kernel of adrenal cyt. b561, determine its relationship to the membrane bilayer, and evaluate the kernel's generality among mammalian cyt. b561 family members; 2) Characterize the interaction of adrenal cyt. b561 with its natural reductant, ascorbate, and its natural oxidant, semidehydroascorbate; and 3) Determine the path of electron flow via adrenal cyt. b561 and its regulation. Planned experiments will be conducted on the native mammalian protein and recombinant wild type and mutant forms of the adrenal cytochrome and other mammalian cyt. b561 family members in prokaryotic and eukaryotic systems that we have developed. We will characterize the topological, structural, and kinetic properties of these recombinant proteins and purified endogenous adrenal cyt b561 using biochemical and biophysical techniques. Understanding how adrenal cyt. b561 functions is a fundamental part of understanding the physiology and pathology of epinephrine and norepinephrine and of some peptide hormones in humans. Defining similarities and differences between adrenal cyt. b561 and recently-discovered human cyt. b561 family members will accelerate characterization of the physiological and pathological roles of the newer cyt. b561s.