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Creating and Applying a Reference to Facilitate the Discussion and Classification of Proteins in a Diverse Group

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Published on: August 16, 2017

θ-Defensins: cyclic peptides with endless potential.

Robert I Lehrer¹, Alex M Cole, Michael E Selsted

¹Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California 90095-1688, USA. rlehrer@mednet.ucla.edu

The Journal of Biological Chemistry

|June 16, 2012

Summary

This summary is machine-generated.

Cyclic θ-defensins, found in primates, are unusual peptides with broad antimicrobial and antiviral activity. Synthetic versions, retrocyclins, show therapeutic potential against infections like HIV and SARS-CoV.

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Area of Science:

Biochemistry
Immunology
Peptide Science

Background:

θ-Defensins are unique cyclic animal peptides found in leukocytes, characterized by a chimera structure and tridisulfide array.
Human θ-defensin genes are non-functional due to a premature stop codon, preventing their natural occurrence.

Purpose of the Study:

To investigate the structure, biogenesis, and therapeutic potential of θ-defensins and their synthetic analogs, retrocyclins.
To explore the host defense activities of these peptides against various pathogens.

Main Methods:

Isolation and characterization of θ-defensins from primate leukocytes.
Synthesis of retrocyclins based on human θ-defensin pseudogenes.
In vitro and in vivo assays to evaluate antiviral, antibacterial, and protective activities.

Main Results:

θ-Defensins exhibit a unique head-to-tail spliced structure with multiple arginines and a tridisulfide array.
Retrocyclin-1 demonstrated inhibition of HIV-1, HSV, and influenza A virus entry.
RTD-1 and retrocyclin-1 provided protection against SARS-CoV and Bacillus anthracis infections in mouse models.

Conclusions:

The unique structure and broad host defense activities of θ-defensins and retrocyclins highlight their potential as novel therapeutic agents.
Further research into these cyclic peptides could lead to new strategies for combating infectious diseases.