Peptide directorySkin, immune & repair

HNP-2

Not a gene product but a trimming: HNP-1 or HNP-3 without their first residue.

Where it comes from

Made in
Formed in the neutrophil granule when HNP-1 or HNP-3 loses its first amino acid
Sent out by
With the other neutrophil peptides
Acts on
  • Bacteria, fungi, enveloped viruses
  • Immune cells

What it does

  • Kills microbes like HNP-1
  • One of the three defensins that make up about five percent of a neutrophil’s protein
  • Shows how a single gene yields several active forms

In medicine

  • Nothing of its own: the assays used in research count it with HNP-1 and HNP-3, so what is reported from sputum or blood is the sum of the three 1
  • It has never been given as a medicine, and no trial separates it from the peptides it is cut from

Beyond the body’s own use

  • It is not the product of a gene of its own. Promyelocytes cut a 94-amino-acid precursor down through two intermediates inside the granule, and a last trim removes the first residue of HNP-1 or HNP-3 2
  • Why the cell bothers is unknown: the trim does not switch the killing off, and no job has been found for the shorter form that HNP-1 does not already do 1

Sources

  1. Ganz et al., Defensins: natural peptide antibiotics of human neutrophils, Journal of Clinical Investigation 1985
  2. Valore & Ganz, Posttranslational processing of defensins in immature human myeloid cells, Blood 1992

This card describes what a medicine is for and what the evidence says; it recommends nothing. Talk to your clinician about anything you read here.