CAREER: Mechanistic and Biosynthetic Studies of Dinoflagellate Bioluminescence

职业：甲藻生物发光的机理和生物合成研究

• 批准号: 1555138
• 负责人: Steven Mansoorabadi
• 金额: $ 70.3万
• 依托单位: Auburn University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-05-01 至 2022-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1555138&HistoricalAwards=false
• 关键词: CAREER; Mechanistic; Biosynthetic; Studies; Dinoflagellate

With this award, the Chemistry of Life Processes Program in the Chemistry Division is funding Dr. Steven O. Mansoorabadi from Auburn University, whose research project is focused on mechanistic and biosynthetic studies of dinoflagellate bioluminescence. Dinoflagellates are an important group of microorganisms found in freshwater and marine environments. Certain dinoflagellates produce potent toxins and cause red tides, which have a significant negative impact on coastal ecosystems and the health of humans and marine wildlife. Several species of dinoflagellates are both photosynthetic and bioluminescent, and are responsible for the bright blue glow of the sea. Dinoflagellates produce light in response to physical agitation using an enzyme known as dinoflagellate luciferase. The substrate of this enzyme, luciferin, is produced from chlorophyll by an unknown pathway. This research project aims to provide a better understanding of the dinoflagellate bioluminescence system by elucidating the mechanism of light production by dinoflagellate luciferase and the biosynthetic pathway for the production of luciferin. These studies help facilitate the use of dinoflagellate luciferase as a cellular imaging agent, and may lead to the development of algicides for the remediation of coastal seawater. This project also integrates bioluminescence, an exciting and fascinating natural phenomenon, into two K-12 outreach initiatives designed to attract and inspire young students to pursue careers in science and related fields. It will also include students in the Auburn University Summer Science Institute directed at gifted high school students and the AU Explore a program that engages middle school students from predominantly rural schoolsDinoflagellate luciferase is a model system for the study of both pH-dependent enzyme regulation and the chemical mechanism of biological chemiluminescence, neither of which are well understood. To gain insight into the regulation of dinoflagellate luciferase, the magnitude and timescale of the pH-induced conformational change and the associated variations in structure and dynamics is determined using time-resolved photothermal methods, constant pH molecular dynamics simulations, and hydrogen/deuterium exchange mass spectrometry. The detailed mechanism by which dinoflagellate luciferase produces light is investigated by determining the structure of the luminophore and other key catalytic intermediates using a combination of transient kinetic and spectroscopic methods and time-dependent density functional theory calculations. In addition, the identity of active site residues important for substrate binding and catalysis is ascertained using mutational analysis. Finally, insight into the pathway of chlorophyll catabolism leading to the formation of dinoflagellate luciferin is obtained through the biochemical and structural characterization of identified biosynthetic intermediates and enzymes. Together, these studies provide significant insight into the biochemistry of these important marine microorganisms and afford excellent interdisciplinary training opportunities for undergraduate and graduate students.

通过这一奖项，化学部的生命过程化学项目资助了奥本大学的Steven O.Mansoorabadi博士，他的研究项目重点是甲藻生物发光的机械和生物合成研究。甲藻是发现于淡水和海洋环境中的一类重要微生物。某些甲藻产生强烈的毒素并引起赤潮，对沿海生态系统以及人类和海洋野生动物的健康产生重大负面影响。有几种甲藻既具有光合作用，又具有生物发光功能，是海洋发出明亮蓝色光芒的原因。甲藻利用一种被称为甲藻荧光素酶的酶，在物理刺激下产生光。这种酶的底物，荧光素，是由叶绿素通过一种未知的途径产生的。本研究旨在通过阐明甲藻荧光素酶的发光机制和合成荧光素的生物合成途径，更好地了解甲藻的生物发光系统。这些研究有助于促进使用甲藻荧光素酶作为细胞成像剂，并可能导致开发用于修复沿海海水的杀藻剂。该项目还将生物发光这一令人兴奋和迷人的自然现象纳入两项旨在吸引和激励年轻学生在科学和相关领域从事职业的K-12外联活动。它还将包括奥本大学夏季科学研究所的学生，该研究所针对有天赋的高中生和非盟探索一个项目，该项目吸引主要来自农村学校的中学生。双鞭毛体荧光素酶是一个研究pH依赖的酶调节和生物化学发光的化学机制的模式系统，这两个方面都不是很好的了解。为了深入了解甲藻荧光素酶的调控，利用时间分辨光热方法、恒定pH分子动力学模拟和氢/氢交换质谱仪，确定了pH诱导的构象变化的大小和时间尺度以及相关的结构和动力学变化。通过结合瞬时动力学和光谱方法以及含时密度泛函理论计算确定发光团和其他关键催化中间体的结构，研究了甲藻荧光素酶发光的详细机制。此外，通过突变分析确定了对底物结合和催化重要的活性部位残基的同一性。最后，通过对已鉴定的生物合成中间体和酶的生化和结构表征，深入了解了叶绿素分解代谢导致甲藻荧光素形成的途径。总之，这些研究为这些重要的海洋微生物的生物化学提供了重要的洞察力，并为本科生和研究生提供了绝佳的跨学科培训机会。

项目成果

Constant pH Accelerated Molecular Dynamics Investigation of the pH Regulation Mechanism of Dinoflagellate Luciferase

• DOI: 10.1021/acs.biochem.7b00873
• 发表时间: 2018-01-23
• 期刊: BIOCHEMISTRY
• 影响因子: 2.9
• 作者: Donnan, Patrick H.;Ngo, Phong D.;Mansoorabadi, Steven O.
• 通讯作者: Mansoorabadi, Steven O.

Investigation of the Dinoflagellate Bioluminescence Mechanism: Chemically Initiated Electron Exchange Luminescence or Twisted Intramolecular Charge Transfer?

• DOI: 10.1002/cptc.201700060
• 发表时间: 2017-09
• 期刊: International Journal of Molecular Sciences
• 影响因子: 5.6
• 作者: Phong D. Ngo;S. Mansoorabadi

MRP.py: A Parametrizer of Post-Translationally Modified Residues

MRP.py：翻译后修饰残基的参数化器

• DOI: 10.1021/acs.jcim.0c00472
• 发表时间: 2020
• 期刊: Journal of Chemical Information and Modeling
• 影响因子: 5.6
• 作者: Sahrmann, Patrick G.;Donnan, Patrick H.;Merz, Kenneth M.;Mansoorabadi, Steven O.;Goodwin, Douglas C.
• 通讯作者: Goodwin, Douglas C.