Backbone cyclization of a recombinant cystine-knot peptide by engineered Sortase A

FEBS Lett. 2014 Nov 28;588(23):4487-96. doi: 10.1016/j.febslet.2014.10.020.

Abstract

Cyclotides belong to the family of cyclic cystine-knot peptides and have shown promise as scaffolds for protein engineering and pharmacological modulation of cellular protein activity. Cyclotides are characterized by a cystine-knotted topology and a head-to-tail cyclic polypeptide backbone. While they are primarily produced in plants, cyclotides have also been obtained by chemical synthesis. However, there is still a need for methods to generate cyclotides in high yields to near homogeneity. Here, we report a biomimetic approach which utilizes an engineered version of the enzyme Sortase A to catalyze amide backbone cyclization of the recombinant cyclotide MCoTI-II, thereby allowing the efficient production of active homogenous species in high yields. Our results provide proof of concept for using engineered Sortase A to produce cyclic MCoTI-II and should be generally applicable to generating other cyclic cystine-knot peptides.

MeSH terms

  • Amino Acid Sequence
  • Aminoacyltransferases / chemistry
  • Aminoacyltransferases / genetics
  • Aminoacyltransferases / metabolism*
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Cyclization
  • Cysteine Endopeptidases / chemistry
  • Cysteine Endopeptidases / genetics
  • Cysteine Endopeptidases / metabolism*
  • Cystine / chemistry*
  • Models, Molecular
  • Molecular Sequence Data
  • Peptides, Cyclic / chemistry*
  • Peptides, Cyclic / metabolism*
  • Protein Conformation
  • Protein Engineering*
  • Recombinant Proteins / chemistry*
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism*
  • Staphylococcus aureus / enzymology

Substances

  • Bacterial Proteins
  • Peptides, Cyclic
  • Recombinant Proteins
  • Cystine
  • Aminoacyltransferases
  • sortase A
  • Cysteine Endopeptidases