LL-37 pentamide is a 37-amino-acid synthetic analog developed from the human host defense peptide LL-37. The designation pentamide refers to modification of five acidic positions in the peptide design rather than to peptide length.

The published construct was developed to investigate how neutralization of acidic side chains changes the overall cationic character and antimicrobial behavior of LL-37. It therefore provides a useful research system for studying peptide charge, membrane interaction, bacterial susceptibility, and antimicrobial peptide engineering.

Product Information

Why the Pentamide Variant Was Designed

Native human LL-37 contains several acidic residues that partially offset its positively charged Lys and Arg residues.

In the original pentamide design, acidic Asp and Glu positions were replaced with their corresponding neutral amide-bearing residues, Asn and Gln. The resulting construct increased the net positive charge relative to the LL-37 peptide examined in that study.

This makes AS2700 particularly informative for experiments testing whether electrostatic charge rather than peptide length alone alters interaction with negatively charged bacterial surfaces.

Antimicrobial Activity and Charge

The original LL-37 pentamide study compared the modified peptide with LL-37 under controlled antimicrobial assay conditions.

The pentamide construct showed substantially greater activity against several staphylococcal strains under physiologically relevant salt conditions. Enhanced activity was also reported in selected bacterial models, although the magnitude of the difference varied by organism.

These results illustrate an important principle in antimicrobial peptide research: increasing cationicity can alter microbial interaction, but the effect remains organism- and assay-dependent.

AS2700 should therefore be treated as a defined experimental analog rather than as a universally more active form of LL-37.

Comparing Pentamide with Native LL-37

The most informative use of this peptide is often a direct comparison with LL-37, Antimicrobial Peptide, Human (AS2699).

A matched experiment can evaluate how changes in charge distribution affect bacterial membrane interaction, antimicrobial activity, ionic-strength sensitivity, or other physicochemical properties while maintaining a closely related LL-37-derived scaffold.

Researchers developing additional charge variants, alanine substitutions, truncated sequences, or modified host defense peptides can use our Custom Peptide Synthesis capabilities for project-specific analog production.

Laboratory Considerations

Because the biological rationale for LL-37 pentamide is strongly related to electrostatics, assay buffer deserves particular attention.

Salt concentration, pH, microbial surface properties, peptide concentration, and medium composition can influence apparent potency. Comparative experiments are therefore most informative when native LL-37 and the pentamide analog are tested under identical conditions.

For cell-associated assays, counterion and endotoxin requirements can also be considered according to the downstream workflow.

Analytical Quality

The 37-residue sequence should be evaluated using molecular identity and chromatographic purity data appropriate to the selected specification.

Our Peptide Quality Control resource provides additional information on analytical HPLC, mass spectrometry, and batch documentation.

Storage and Handling

Store the lyophilized material under the conditions specified for the supplied batch. After reconstitution, use consistent solvent, concentration, temperature, and aliquoting procedures when comparing AS2700 with native LL-37 or other analogs.

Research Use Only

LL-37 pentamide is supplied for research use only. It is not intended for therapeutic, or human use.