Cebulassopins, Antiproliferative Lasso Peptides from a Split Biosynthetic Operon

Area of Science:

• Biochemistry
• Molecular Biology
• Natural Products Chemistry

Background:

• Lasso peptides possess a unique threaded topology and are typically synthesized via gene clusters where precursor genes are adjacent to modification enzymes.
• Previous studies have focused on contiguous gene clusters for lasso peptide biosynthesis.

Purpose of the Study:

• To report the discovery and characterization of cebulassopins A-D, a new class of lasso peptides.
• To investigate the unique biosynthetic pathway involving a split operon for lasso peptide production.
• To evaluate the antiproliferative activity of these novel compounds.

Main Methods:

• Structure elucidation of cebulassopins A-D using spectroscopic methods.
• Computational analysis to determine the three-dimensional topology of selected compounds.
• In vitro antiproliferative assays against human lung carcinoma cell lines.

Main Results:

• Identification of four new lasso peptides, cebulassopins A-D (1-4).
• Demonstration of a novel split operon mechanism for lasso peptide biosynthesis, with distant precursor genes.
• Cebulassopins exhibited potent antiproliferative activity with sub-micromolar inhibitory concentrations against lung cancer cells.

Conclusions:

• Cebulassopins represent the first characterized lasso peptides biosynthesized via a split operon.
• The potent antiproliferative effects highlight their potential as therapeutic agents for lung cancer.
• Further research into split lasso peptide gene clusters may uncover new bioactive natural products.