Disambiguation
Which DGK-17?
Searching for DGK-17 returns two entirely unrelated subjects: a synthetic antimicrobial peptide and a bacterium found in kimchi. Neither is a variant of the other. They are separated here so that a search for the name resolves to the right thing.
Side by side
Two entities, one designation
Entity 1 · a molecule
D-GK17
A synthetic peptide: seventeen D-amino acids corresponding to residues 14–30 of human cathelicidin LL-37.
Designed for protease resistance; studied for antimicrobial and antibiofilm activity and for immunomodulation.
Described in Cell Biomaterials, April 2026.
Entity 2 · an organism
L. plantarum DGK-17
A living bacterium: a lactic acid bacterium strain isolated from kimchi.
Used to ferment soybean seed powder; the resulting extract was studied in colon cancer cells.
Described in J Food Sci, June 2017 — PMID 28488794.
The relationship between them is none. Not a derivative, not a producer, not a source. A peptide and a bacterium that happen to carry the same string.
Entity 1
D-GK17, the peptide
The designation encodes its chemistry. D for the all-D chirality; GK from the sequence; 17 for the residue count. It is derived from the central region of LL-37, the mature antimicrobial peptide released from the human precursor hCAP18 — a lineage set out in full on hcap18.com.
MechanismBuilding it entirely from D-amino acids makes it a mirror image of a natural peptide, which the body's proteases cannot seat in their active sites. The reported consequence is a peptide that keeps antimicrobial activity in serum and wound environments where an L-peptide would be degraded.
The full account, with the qualifier on which findings were read at source and which were not, is on the main resource. The chirality strategy itself is on the D-amino acid peptides page.
Entity 2
Lactiplantibacillus plantarum DGK-17, the strain
Primary sourceLactobacillus plantarum DGK-17 — the genus was reclassified as Lactiplantibacillus in 2020, so both names appear in the literature for the same organism — is documented as previously isolated from kimchi. In work from the Department of Biotechnology at Daegu University, soybean seed powder was fermented with the strain and the resulting extract examined in human colon cancer cells.1
The reported findings concern the fermented extract rather than the organism in isolation: morphological change and reduced colony formation in HCT-116 cells, apoptotic cell death with an IC50 reported at 111 µg, and involvement of ROS and JNK signalling.
It has no described relationship to cathelicidin, to LL-37, to antimicrobial peptides or to biofilm. As of this page's literature review date it is the only PubMed-indexed record naming the strain.
- Apoptotic activity of Lactobacillus plantarum DGK-17-fermented soybean seed extract in human colon cancer cells via ROS-JNK signaling pathwayPMID 28488794
Why it happens
Two naming conventions that never had to agree
Peptide names are often built from the molecule: a chirality marker, a couple of residue letters, a length. Strain designations are isolate labels — a laboratory prefix and a number, assigned when the organism is deposited, carrying no chemical meaning at all.
Neither convention consults the other, and neither is wrong. The collision is coincidental, and the only cost of it falls on the reader — which is what this page exists to remove.
MechanismA practical test if you are unsure which one a source means: look for a sequence and a residue count, or for a culture collection and a growth medium. Sources describing the peptide give the first; sources describing the strain give the second. No paper gives both, because no work involves both.
Questions
Frequently asked
Is DGK-17 a peptide or a bacterium?
Both names exist, and they are unrelated. D-GK17 is a synthetic all-D peptide from residues 14–30 of human cathelicidin LL-37. Lactiplantibacillus plantarum DGK-17 is a lactic acid bacterium isolated from kimchi.
What is Lactiplantibacillus plantarum DGK-17 studied for?
Fermentation. The published work ferments soybean seed powder with the strain and examines the resulting extract in HCT-116 human colon cancer cells, reporting apoptosis via ROS-JNK signalling with an IC50 of 111 µg. The findings concern the fermented extract rather than the organism alone.
Why is the genus written two different ways?
The genus Lactobacillus was split in 2020 and this species became Lactiplantibacillus plantarum. Papers published before the reclassification use the older name, so both appear in the literature for the same organism. That is a rename, not a second entity — unlike the peptide, which genuinely is one.
Does the bacterium produce the peptide?
No. Nothing in the literature connects them. The peptide is chemically synthesised from D-amino acids and derived from a human gene product; the strain is a food-fermentation organism. Attributing either one's properties to the other would be an error.
How do I tell which one a source is discussing?
Look for a sequence and a residue count, which identifies the peptide, or for a culture collection and a growth medium, which identifies the strain. No single source describes both.
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