How a Milk-Derived Peptide Kills Gram-Negative Bacteria by Changing Its Shape | Research

The takeaway

Bovine lactoferricin fights four types of Gram-negative bacteria by transforming its molecular structure through disulfide bond formation.

4 Gram-negative bacteria killed
Bovine lactoferricin with its disulfide-bonded structure was effective against four pathogenic bacterial species

What the researchers found

The intramolecular disulfide bond in bovine lactoferricin transforms its molecular structure, which is essential for its antibacterial activity against four Gram-negative pathogenic bacteria.

Why it matters

Understanding how structural changes enable antimicrobial activity helps scientists design more effective peptide antibiotics, potentially overcoming the growing threat of antibiotic-resistant Gram-negative infections.

The numbers in context

Three variants: native Lfcin, Lfcin with disulfide bond (Lfcin DB), and mutant without disulfide bond (Lfcin C36G). Structural analysis by circular dichroism and AlphaFold3 prediction. Tested against four Gram-negative pathogens.

How the study worked

In vitro study synthesizing bovine lactoferricin variants with and without disulfide bonds, testing antibacterial activity against four Gram-negative pathogens, and characterizing structural changes.

Who was studied

Not applicable (peptide biochemistry)

What this study cannot tell us

In vitro study — antibacterial activity in a test tube may not translate to efficacy in living organisms. Bioavailability and stability in the body remain to be tested.

How to read the evidence

In vitro laboratory study providing mechanistic insight into peptide antimicrobial activity. Clinical relevance depends on future in vivo testing.

When this study was published

Published in 2025, advancing understanding of milk-derived antimicrobial peptide mechanisms.

The bigger picture

Milk-derived peptides represent a natural source of antimicrobials. Understanding the structure-activity relationship of lactoferricin could guide the design of new peptide therapeutics and food preservation agents.

Questions still open

Can lactoferricin structure be engineered for enhanced potency against specific resistant bacteria?
Would oral lactoferricin survive digestion and remain antimicrobially active?

Common questions

What is lactoferricin?

Lactoferricin is a small antimicrobial peptide found within lactoferrin, a protein naturally present in milk. It serves as the antimicrobial "active center" of the larger protein and can kill bacteria by disrupting their cell membranes.

Could lactoferricin replace antibiotics?

It shows promise as a potential alternative for certain infections, particularly against Gram-negative bacteria that are increasingly antibiotic-resistant. However, challenges like stability and delivery need to be solved before clinical use.

Read the original research

Bovine lactoferricin exerts antibacterial activity against four Gram-negative pathogenic bacteria by transforming its molecular structure.

Frontiers in cellular and infection microbiology, 15, 1508895

View on PubMed ↗Publisher’s paper ↗

Citation

Pei, Jie; Xiong, Lin; Wu, Xiaoyun; Chu, Min; Bao, Pengjia; Ge, Qianyun; Guo, Xian. (2025). Bovine lactoferricin exerts antibacterial activity against four Gram-negative pathogenic bacteria by transforming its molecular structure.. Frontiers in cellular and infection microbiology, 15, 1508895. https://doi.org/10.3389/fcimb.2025.1508895