Related Experiment Video
Updated: Jun 26, 2026

Synthesis of Masarimycin, a Small Molecule Inhibitor of Gram-Positive Bacterial Growth
Published on: January 7, 2022
Suramin inhibits macrophage activation by human group IIA phospholipase A2, but does not affect bactericidal activity
E A Aragão1, L Chioato, T L Ferreira
1Department of Chemistry, FFCLRP-USP, Universidade de São Paulo, São Paulo, Brazil.
Objective:
Suramin is a polysulphonated napthylurea antiprotozoal and anthelminitic drug, which also presents inhibitory activity against a broad range of enzymes. Here we evaluate the effect of suramin on the hydrolytic and biological activities of secreted human group IIA phospholipase A(2) (hsPLA(2)GIIA).
Materials And Methods:
The hsPLA(2)GIIA was expressed in E. coli, and refolded from inclusion bodies. The hydrolytic activity of the recombinant enzyme was measured using mixed dioleoylphosphatidylcholine/dioleoylphosphatidylglycerol (DOPC/DOPG) liposomes. The activation of macrophage cell line RAW 264.7 by hsPLA(2) GIIA was monitored by NO release, and bactericidal activity against Micrococcus luteus was evaluated by colony counting and by flow cytometry using the fluorescent probe Sytox Green.
Results:
The hydrolytic activity of the hsPLA(2) GIIA was inhibited by a concentration of 100 nM suramin and the activation of macrophages by hsPLA(2) GIIA was abolished at protein/suramin molar ratios where the hydrolytic activity of the enzyme was inhibited. In contrast, both the bactericidal activity of hsPLA(2) GIIA against Micrococcus luteus and permeabilization of the bacterial inner membrane were unaffected by suramin concentrations up to 50 microM.
Conclusions:
These results demonstrate that suramin selectively inhibits the activity of the hsPLA(2) GIIA against macrophages, whilst leaving the anti-bacterial function unchanged.
Related Concept Videos
Inhibitors of Bacterial Protein Synthesis
Antiprotozoal Agents
Inhibitors Of Virion Release
Inhibitors of Gram-positive Cell Wall Synthesis
Gene Regulation in Microbial Communities: Quorum Sensing
Antimicrobial Proteins
Interferons
Interferons (IFNs) are proteins produced by lymphocytes, macrophages, and fibroblasts infected with viruses. While IFNs cannot prevent viruses from entering and...

