Biochemistry of Intramembrane Proteases From Pathogens

病原体膜内蛋白酶的生物化学

基本信息

批准号：
7188640
负责人：
SINISA URBAN
金额：
$ 34.95万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2005
资助国家：
美国
起止时间：
2005-06-16 至 2010-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7188640
关键词：
Active Sites Address Alzheimer&apos s Disease Aspartic Endopeptidases Bacterial Adhesins Biochemical Biochemistry Biological Biological Assay Biological Process Calcium Cells Characteristics Cleaved cell Development Disease Drug Delivery Systems Endopeptidases Environment Enzymes Goals Health Heart Human Hydrolysis In Vitro Infection Integral Membrane Protein Invaded Lipids Malaria Maps Membrane Membrane Lipids Membrane Proteins Methods Molecular Object Attachment Organelles Parasites Peptide Hydrolases Peptides Plasmodium Proteins Regulation Research Personnel Role Serine Protease Substrate Specificity Surface Testing Thinking Time Toxoplasma gondii Transmembrane Domain base dimer high throughput screening hypercholesterolemia inhibitor/antagonist insight milligram novel obligate intracellular parasite parasite invasion pathogen pathogenic bacteria presenilin programs reconstitution rhomboid rhomboid catalysis secretase small molecule small molecule libraries success tool

项目摘要

DESCRIPTION (provided by applicant): Parasites Toxoplasma gondii and Plasmodium, the agent of malaria, are deadly human pathogens. These obligate intracellular parasites must invade host cells to survive, making understanding the parasite invasion machinery an important goal. At the heart of this machinery are rhomboid proteases, which catalyze the essential cleavage of parasite adhesin proteins that are required for attachment to host cells. Rhomboids are integral membrane proteins that cross the membrane seven times, and we previously deduced that they function as novel proteases; their transmembrane domains (TMDs) associate to form a serine protease active site within the membrane bilayer. Remarkably, cleavage of adhesins occurs within their TMDs. Such hydrolysis of peptide bonds within the normally hydrophobic environment of the membrane is a new paradigm in enzyme biochemistry. This paradigm is of wider importance to human health as various intramembrane proteases have recently been implicated as central players in Alzheimers Disease, hypercholesterolemia, and infection by pathogenic bacteria. However, the biochemical function of these unusual membrane enzymes is poorly understood. We seek to decipher how these enigmatic proteases function at the molecular level, with particular emphasis on their role in parasite invasion. Specifically, capitalizing on new biochemical methods for studying rhomboids that we have recently developed, we propose to investigate the following key issues: 1) physical basis of rhomboid substrate specificity compared to that of other intramembrane proteases, 2) arrangement and regulation of rhomboids in parasite membranes, 3) structural arrangement and function of rhomboid proteases, 4) development of small molecule inhibitors of rhomboid catalysis.

描述（由申请人提供）：疟疾的寄生虫弓形虫弓形虫和疟原虫是致命的人类病原体。这些义务的细胞内寄生虫必须入侵宿主细胞才能生存，使理解寄生虫入侵机械成为重要目标。这种机械的核心是菱形蛋白酶，它催化寄生虫粘附蛋白的必要裂解，这是宿主细胞附着所需的。菱形是七次穿越膜的整体膜蛋白，我们先前推断出它们充当新的蛋白酶。它们的跨膜结构域（TMDS）关联，在膜双层中形成丝氨酸蛋白酶活性位点。值得注意的是，粘合剂的裂解发生在其TMD中。在膜正常疏水环境中肽键的水解是酶生物化学的新范式。这种范式对人类健康具有广泛的重要性，因为最近各种膜内蛋白酶是阿尔茨海默氏病，高胆固醇血症和致病细菌感染的中心参与者。但是，这些不寻常的膜酶的生化功能知之甚少。我们试图解密这些神秘的蛋白酶在分子水平上的作用，特别是它们在寄生虫侵袭中的作用。 Specifically, capitalizing on new biochemical methods for studying rhomboids that we have recently developed, we propose to investigate the following key issues: 1) physical basis of rhomboid substrate specificity compared to that of other intramembrane proteases, 2) arrangement and regulation of rhomboids in parasite membranes, 3) structural arrangement and function of rhomboid proteases, 4) development of small molecule inhibitors of菱形催化。