Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
Biochemistry. 1999 Jan 12;38(2):643-50.

Determination of substrate specificity for peptide deformylase through the screening of a combinatorial peptide library.

Author information

  • 1Department of Chemistry, Ohio State Biochemistry Program, The Ohio State University, Columbus 43210, USA.

Abstract

Peptide deformylase is an essential Fe2+ metalloenzyme that catalyzes the removal of the N-terminal formyl group from nascent polypeptides in eubacteria. In vivo, the deformylase is capable of deformylating most of the polypeptides in a bacterial cell, which contain diverse N-terminal sequences. In this work, we have developed a combinatorial method to systematically examine the sequence specificity of peptide deformylase. A peptide library that contains all possible N-terminally formylated tetrapeptides was constructed on TentaGel resin, with a unique peptide sequence on each resin bead. Limited treatment with the Escherichia coli deformylase resulted in the deformylation of those peptides that are the most potent substrates of the enzyme. By using an enzyme-linked assay, the beads containing the deformylated peptides were identified and isolated. Peptide sequence analysis using matrix-assisted laser desorption ionization mass spectrometry revealed a consensus sequence, formyl-Met-X-Z-Tyr (X = any amino acid except for aspartate and glutamate; Z = lysine, arginine, tyrosine, or phenylalanine), for the E. coli enzyme. The deformylase is also capable of efficient deformylation of formyl-Phe-Tyr-(Phe/Tyr) peptides. These results demonstrate that, despite being a broad-specificity enzyme, the peptide deformylase deformylates different peptides at drastically different rates. In addition, the selectivity of peptide deformylase for the N-formyl over the N-acetyl group has been studied with N-alpha-fluoroacetyl peptides, and the results suggest that both electronic and steric factors are responsible for the observed specificity. The deformylase was also shown to exhibit esterase activity. These results will facilitate the design of specific deformylase inhibitors as potential antibacterial agents. This combinatorial method should be generally applicable to the study of the substrate specificity of other acylases and peptidases.

PMID:
9888804
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for American Chemical Society
    Loading ...
    Write to the Help Desk