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EntityQ412820· pop 26· linked from 127 articles

Also known as defensins

Defensins are small cysteine-rich cationic proteins across cellular life, including vertebrate and invertebrate animals, plants, and fungi. They are host defense peptides, with members displaying either direct antimicrobial activity, immune signaling activities, or both. They are variously active against bacteria, fungi and many enveloped and nonenveloped viruses. They are typically 18-45 amino acids in length, with three or four highly conserved disulphide bonds.

Key facts

Protein family.Symbol
Defensin
Protein family.Name
Defensin
Protein family.image
Defensin examples.png
Protein family.caption
Example defensins with alpha helix in red, beta strands in blue, disulphide bonds in yellow ()
Protein family.Pfam_clan
CL0075
Protein family.OPM family
54
Protein family.OPM protein
6cs9

via Wikipedia infobox

~11 min read

Encyclopedic overview

15 sections
Contents
  • Varieties
  • Trans-defensins
  • Cis-defensins
  • Related defensin-like proteins
  • Toxins
  • Signalling
  • Enzyme inhibitors
  • Function
  • Pathology
  • Applications
  • Defensins
  • Defensin-mimetics
  • See also
  • References
  • External links

Defensins are small cysteine-rich cationic proteins across cellular life, including vertebrate and invertebrate animals, plants, and fungi. They are host defense peptides, with members displaying either direct antimicrobial activity, immune signaling activities, or both. They are variously active against bacteria, fungi and many enveloped and nonenveloped viruses. They are typically 18-45 amino acids in length, with three or four highly conserved disulphide bonds.

In animals, they are produced by cells of the innate immune system and epithelial cells, whereas in plants and fungi they are produced by a wide variety of tissues. An organism usually produces many different defensins, some of which are stored inside the cells (e.g. in neutrophil granulocytes to kill phagocytosed bacteria), and others are secreted into the extracellular medium. For those that directly kill microbes, their mechanism of action varies from disruption of the microbial cell membrane to metabolic disruption.

Excerpted from Wikipedia’s “defensin” article, available under the CC BY-SA 4.0 licence.