STRUCTURAL BIOLOGY OF MEMBRANE PROTEINS

膜蛋白的结构生物学

• 批准号: 7955553
• 负责人: MICHAEL G MALKOWSKI
• 金额: $ 4.76万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2010-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7955553
• 关键词: Animals; Carbon; Caribbean region; Cells; Computer Retrieval of Information on Scientific Projects Database; Cytochromes; Data Collection; Detergents; Environment; Enzymes; Funding; Grant; Human; Institution; Invertebrates; Laboratories; Light; Lipoxygenase; Membrane; Membrane Proteins; Mus; Oryza sativa; Oxygen; Oxygenases; Plants; Polyunsaturated Fatty Acids; Production; Prostaglandin-Endoperoxide Synthase; Proteins; Research; Research Personnel; Resolution; Resources; Roentgen Rays; Source; Synchrotrons; United States National Institutes of Health; beamline; coral; cyclooxygenase 2; lipid mediator; pathogen; research study; structural biology; synchrotron radiation

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The research focus in the Malkowski laboratory is to understand how different classes of integral membrane enzymes utilize stereoselective oxygenations to generate unique oxylipins from a defined set of polyunsaturated fatty acid (PUFA) substrates. Oxylipins are bioactive lipid mediators found in plants and animals that are biosynthesized from 18-22 carbon PUFAs through the addition of one, two, or four molecules of oxygen via the catalytic activity of cytochrome P450s, lipoxygenases (LOX), and cyclooxygenases (COX), respectively. Diffraction studies are focused on three different integral membrane enzymes involved in oxylipin production in plants, animals, and invertebrates: a) pathogen-inducible oxygenase (PIOX) from Oryza sativa; b) human and murine cyclooxygenase-2 (COX-2); and c) a cyclooxygenase enzyme from the Caribbean coral Plexaura homomalla. Initial diffraction experiments of COX-2, carried out at the National Synchrotron Light Source (beamline X4A; March 2005), confirm that the crystals are in fact protein; however, diffraction was only observed to 6.5¿ resolution. This project requires synchrotron radiation for two major reasons. First, while crystals of COX-2 grow large, they diffract only weakly to 8-10 ¿ on laboratory X-ray sources. Second, their relatively empty unit cell, combined with their sensitivity to any change in the detergent environment, make handling these crystals for data collection difficult. Often many crystals must be screened to find one that maintains minimal mosaicity (<2¿a) and reasonable diffraction.

该副本是使用众多研究子项目之一 由NIH/NCRR资助的中心赠款提供的资源。子弹和 调查员（PI）可能已经从其他NIH来源获得了主要资金， 因此可以在其他清晰的条目中代表。列出的机构是 对于中心，这是调查员的机构。 Malkowski实验室的研究重点是了解不同类别的积分膜酶如何利用立体选择性氧合来从一组定义的多不饱和脂肪酸（PUFA）底物中产生独特的氧合。黄肽是在植物和动物中发现的生物活性脂质介质，它们通过添加一个，两个或四个分子通过细胞色素p450s的催化活性，氧气（Lipoxyganases（Lox）（Lox）和环氧酶（Coxygenganases）（分别），通过添加了18-22碳PUFA的生物合成。衍射研究集中在植物，动物和无脊椎动物中参与黄脂素产生的三种不同的整合膜酶上：a）来自Oryza sativa的病原体诱导型氧合酶（PIOX）； b）人和鼠环氧酶-2（COX-2）； c）来自加勒比珊瑚plexaura homomalla的环氧合酶。 COX-2的初始衍射实验，在国家同步光源（Beamine X4A； 2005年3月）进行，确认晶体实际上是蛋白质。但是，仅观察到衍射为6.5。分辨率。该项目需要同步辐射，原因有两个。首先，尽管COX-2的晶体生长较大，但在实验室X射线源上它们的衍射仅为8-10。其次，它们的相对空单元格与确定环境中任何变化的敏感性相结合，使处理这些晶体以使数据收集变得困难。通常，必须筛选许多晶体，以找到一种保持最小的镶嵌性（<2？）和合理衍射的晶体。