Novel Lasso Peptides as Molecular Scaffolds for Protein Therapeutics, Molecular Sensors and Probes

Description:

Researchers at Princeton University, in the Department of Chemical and Biological Engineering, have engineered a gene cluster which encodes for the biosynthesis of a natural peptide product called Astexin-1. Astexin-1 is a new member of the lasso peptide class. Molecules of this class are highly stable, engineerable and may be utilized as molecular scaffolds for a variety of applications, such as in protein therapeutics and as molecular probes and sensors. An additional advantage of using lasso peptides as a scaffold for peptide drugs is the relative ease of production and purification relative to synthetically made peptides.

To validate a unique genome-mining algorithm to identify lasso peptide gene clusters in prokaryotes, the researchers focused on a single lasso peptide predicted to be produced by the freshwater bacterium Asticcacaulis excentricus. Heterologous expression of an engineered minimal gene cluster in Escherichia Coli led to the production of astexin-1. At 23 amino acids, astexin-1 is the largest lasso peptide isolated to date. ¹Given that lasso peptides have a host of pharmacologically relevant functions including receptor antagonism, enzyme inhibition and inhibition of viral fusion this rich spectrum of activities motivates the search for new lasso peptides. In the meantime, the researchers are focusing on engineering of Astexin-1 for commercial applications.

Applications

· Molecular scaffold for protein therapeutics

· Anti-microbial

· Receptor antagonism

· Enzyme inhibition

Advantages

· Intra- cellular natural product

· Ease of expression and subsequent purification

· Amenable to amino acid substitution with epitopes of interest

Publications:

¹Maksimov M.O., Pelczer I., Link A.J., Precursor-centric genome-mining approach for lasso peptide discovery, PNAS, September 18, 2012, Vol. 109, 38, Pg 15223-15228.

Stage of Development

In addition to Astexin-1 the inventors have identified additional lasso peptides with unique properties amenable to various applications. Further testing of these engineered peptides is ongoing

The Inventors

A. James Link is an Assistant Professor of Chemical and Biological Engineering in Princeton University. The research in the Link group is highly interdisciplinary and focuses on protein engineering and chemical biology. One of the major focuses of the Link group is to apply directed evolution, an experimental algorithm that mimics Darwinian evolution, to medically relevant proteins. His research approach is to engineer proteins by utilizing directed evolution to introduce new functions into proteins. The library of protein variants is then screened to identify those members of the population with the highest levels of function or activity. Dr. Link has been recognized with an NSF CAREER Award in 2010 and was named a DuPont Young Professor in 2011 and a Sloan Research Fellow in Chemistry in 2013.