Mapping and Exploiting the Promiscuity of OxyB toward the Biocatalytic Production of Vancomycin Aglycone Variants.

TitleMapping and Exploiting the Promiscuity of OxyB toward the Biocatalytic Production of Vancomycin Aglycone Variants.
Publication TypeJournal Article
Year of Publication2020
AuthorsForneris, CC, Nguy, AKL, Seyedsayamdost, MR
JournalACS Catal
Volume10
Issue16
Pagination9287-9298
Date Published2020/08/21
ISSN2155-5435
Abstract

Vancomycin is one of the most important clinical antibiotics in the fight against infectious disease. Its biological activity relies on three aromatic cross-links, which create a cup-shaped topology and allow tight binding to nascent peptidoglycan chains. The cytochrome P450 enzymes OxyB, OxyA, and OxyC have been shown to introduce these synthetically challenging aromatic linkages. The ability to utilize the P450 enzymes in a chemo-enzymatic scheme to generate vancomycin derivatives is appealing but requires a thorough understanding of their reactivities and mechanisms. Herein, we systematically explore the scope of OxyB biocatalysis and report installation of diverse diaryl ether and biaryl cross-links with varying macrocycle sizes and compositions, when the enzyme is presented with modified vancomycin precursor peptides. The structures of the resulting products were determined using one-dimensional/two-dimensional nuclear magnetic resonance spectroscopy, high-resolution mass spectrometry (HR-MS), tandem HR-MS, and isotopic labeling, as well as ultraviolet-visible light absorption and fluorescence emission spectroscopies. An exploration of the biological activities of these alternative OxyB products surprisingly revealed antifungal properties. Taking advantage of the promiscuity of OxyB, we chemo-enzymatically generated a vancomycin aglycone variant containing an expanded macrocycle. Mechanistic implications for OxyB and future directions for creating vancomycin analogue libraries are discussed.

DOI10.1021/acscatal.0c01719
Alternate JournalACS Catal
PubMed ID34422446
PubMed Central IDPMC8378672
Grant ListR01 GM129496 / GM / NIGMS NIH HHS / United States