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Updated: Feb 6, 2026

Defining Substrate Specificities for Lipase and Phospholipase Candidates
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Defining Substrate Specificities for Lipase and Phospholipase Candidates

Published on: November 23, 2016

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Search and Subvert: Minimalist Bacterial Phosphatidylinositol-Specific Phospholipase C Enzymes

Mary F Roberts1, Hanif M Khan, Rebecca Goldstein1

  • 1Department of Chemistry , Boston College , Chestnut Hill , Massachusetts 02467 , United States.

Chemical Reviews
|August 28, 2018
PubMed

Insights

Gram-positive bacterial phosphatidylinositol-specific phospholipase C (PI-PLC) enzymes are secreted virulence factors. Research reveals their membrane binding and catalytic mechanisms, aiding in understanding host-pathogen interactions.

Area of Science:

  • Microbiology
  • Biochemistry
  • Structural Biology

Background:

  • Phosphatidylinositol-specific phospholipase C (PI-PLC) enzymes are secreted by Gram-positive bacteria.
  • These enzymes function as virulence factors, contributing to the downregulation of host immunity.
  • PI-PLCs possess a unique distorted (βα)8 TIM barrel fold, crucial for their function.

Purpose of the Study:

  • To elucidate the molecular mechanisms of catalysis and membrane binding in bacterial PI-PLCs.
  • To understand how variations in enzyme structure influence substrate targeting on host cell membranes.
  • To develop a semiquantitative model for PI-PLC-mediated substrate cleavage.

Main Methods:

  • Utilized advanced techniques including 31P field-cycling NMR relaxometry to study protein-lipid interactions.
  • Employed molecular dynamics simulations to investigate electrostatic and cation-π interactions in lipid binding.
  • Applied single molecule fluorescence measurements to analyze dynamic interactions between PI-PLCs and vesicles.

Main Results:

  • Characterized the interplay between catalysis and membrane binding in PI-PLCs.
  • Identified conserved catalytic amino acids within a stable scaffold and variable loops for membrane recognition.
  • Demonstrated how sequence and structural variations affect enzyme-membrane interactions and substrate search.

Conclusions:

  • A comprehensive understanding of PI-PLC molecular mechanisms has been achieved.
  • The developed methods are applicable to other peripheral membrane proteins, including bacterial and eukaryotic orthologues.
  • This research provides insights into host-pathogen interactions and potential therapeutic targets.

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