Enzymatic Cross-Linking of Side Chains Generates a Modified Peptide with Four Hairpin-like Bicyclic Repeats

Biochemistry. 2017 Sep 19;56(37):4927-4930. doi: 10.1021/acs.biochem.7b00808. Epub 2017 Sep 6.

Abstract

Macrocyclization of peptides is often employed to generate novel structures and biological activities in the biosynthesis of natural products and drug discovery. The enzymatic cross-linking of two side chains in a peptide via an ester or amide has a high potential for making topologically diverse cyclic peptides but is found with only a single consensus sequence in the microviridin class of natural products. Here, we report that a peptide with a new sequence pattern can be enzymatically cross-linked to make a novel microviridin-like peptide, plesiocin, which contains four repeats of a distinct hairpin-like bicyclic structure and shows strong inhibition of proteases. A single ATP-grasp enzyme binds to a leader peptide, of which only 13 residues are required for binding, and performs eight esterification reactions on the core peptide. We also demonstrate that the combination of tandem mass spectrometry and an ester-specific reaction greatly facilitates the determination of connectivity. We suggest that the enzymatic cross-linking of peptide side chains can generate more diverse structures in nature or by engineering.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aquatic Organisms / enzymology
  • Aquatic Organisms / metabolism*
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / metabolism
  • Bacterial Proteins / pharmacology
  • Chromatography, High Pressure Liquid
  • Chymotrypsin / antagonists & inhibitors
  • Chymotrypsin / metabolism
  • Drug Design*
  • Esterification
  • Hydrophobic and Hydrophilic Interactions
  • Inverted Repeat Sequences
  • Kinetics
  • Molecular Structure
  • Multigene Family
  • Myxococcales / enzymology
  • Myxococcales / metabolism*
  • Pancreatic Elastase / antagonists & inhibitors
  • Pancreatic Elastase / metabolism
  • Peptides / chemistry
  • Peptides / metabolism*
  • Peptides / pharmacology
  • Peptides, Cyclic / chemistry
  • Peptides, Cyclic / metabolism*
  • Peptides, Cyclic / pharmacology
  • Protease Inhibitors / chemistry
  • Protease Inhibitors / metabolism*
  • Protease Inhibitors / pharmacology
  • Protein Conformation
  • Protein Processing, Post-Translational*
  • Proteolysis / drug effects
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
  • Tandem Mass Spectrometry

Substances

  • Bacterial Proteins
  • Peptides
  • Peptides, Cyclic
  • Protease Inhibitors
  • plesiocin
  • Chymotrypsin
  • Pancreatic Elastase