CRYPTIC METABOLITES AND METHOD FOR ACTIVATING SILENT BIOSYNTHETIC GENE CLUSTERS IN DIVERSE MICROORGANISMS

摘要

Microorganisms are prolific producers of natural products, a group of molecules that make up the majority of drugs approved by the FDA in the past 35 years. After decades of mining, the low-hanging fruit has been picked and so discovery of drug-like molecules from microorganisms has come to a near-halt. The reason for this lack of productivity is that most biosynthetic pathways that give rise to natural products are not active under typical laboratory growth conditions. These so-called ‘cryptic’ or ‘silent’ pathways are a major source of new bioactive molecules and methods that reliably activate them could have a profound impact on drug discovery. Disclosed herein is a rapid genetics-free method for eliciting and detecting cryptic metabolites using an imaging mass spectrometry-based approach. An organism of choice is challenged with elicitors from a small molecule library. The molecules elicited are then imaged by mass spec, which allows for rapid identification of cryptic metabolites. These are then isolated and characterized. Employing the disclosed approach activated production of cryptic glycopeptides from an actinomycete bacterium. The molecules that result, the keratinimicins and keratinicyclins, are metabolites with important structural features. At least two of these, keratinimicins B and C, are highly bioactive against several pathogenic strains. This approach will allow for rapid activation and identification of cryptic metabolites from diverse microorganisms in the future.