Excellence in Research: Biosynthetic investigation of manzamine class alkaloids

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Manzamines are members of marine alkaloid natural products. They possess complex structures and exhibit a number of biological activities, including anticancer and antibacterial activities. Lack of knowledge of the molecular and biochemical basis for the production of these alkaloids has been a major barrier to the bioengineering of new alkaloid derivatives. This project will provide such knowledge and will serve as the foundation for bioengineering of new manzamine derivatives with potential applications in medicine, agriculture and biotechnology. This project will also provide extensive research experiences for University of Maryland Eastern Shore undergraduate and graduate students, many of whom are from groups underrepresented in STEM, and thus the work will contribute to development of a diverse STEM workforce. Manzamines represent a structurally distinct group of marine alkaloid natural products with little resemblance to other alkaloids. The structural uniqueness of manzamines, including manzamine A arises from the assembly of a complex pentacyclic core attached to a beta-carboline unit. Although over a hundred manzamines that exhibit a wide range of biological activities have been isolated primarily from marine sponges, how organisms assemble building blocks and intermediates to furnish complex structural scaffolds of manzamines has remained a mystery. The main objective of the proposed project is to identify biosynthetic building blocks and pathway intermediates and elucidate key biosynthetic steps involved in the production of manzamine A. The proposed project utilizes a multi-pronged experimental approach including: (A) isotope incorporation experiments to identify biosynthetic building blocks of the beta-carboline and the pentacyclic ring, (B) experiments to identify the enzyme involved in the attachment of these two structural units, (C) complete genome sequence analysis of Micromonospora sp. M42 for identifying manzamine biosynthetic locus, and (D) heterologous production and characterization of select enzymes involved in the manzamine A biosynthetic pathway. The results garnered through this project will pave the way for the discovery of other manzamines through bioinformatic analysis. Manzamine A biosynthetic enzymes with potentially new catalytic activities will be an invaluable addition to the existing repertoire of tools for the further advancement of research projects concerning biosynthetic pathway engineering/synthetic biology, particularly for the production of new manzamine analogs. The proposed project thus offers a biological alternative to the synthetic production of new manzamine alkaloids.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.