Pentapeptide-3 (KTTKS) – CAS 135679-88-8
Pentapeptide-3 is the water-soluble five-amino-acid sequence Lys-Thr-Thr-Lys-Ser (KTTKS), a fragment of type I procollagen that serves as one of the foundational collagen-signalling peptides in cosmetic science. With a molecular weight of approximately 550 Da and CAS number 135679-88-8, this peptide represents the precursor concept behind Matrixyl (Palmitoyl Pentapeptide-4), but without the palmitoyl lipid chain. The absence of the fatty acid tail gives Pentapeptide-3 full water solubility, opening formulation possibilities that lipopeptide variants cannot address.
Mechanism of Action
The KTTKS sequence was originally identified as a cleavage fragment released during the processing of type I procollagen into mature collagen fibrils. When this fragment is present in the extracellular space, fibroblasts interpret it as a signal that matrix turnover is occurring and respond by upregulating synthesis of collagens I and III, fibronectin, and elastin. This positive feedback mechanism makes KTTKS a classical matrikine: a peptide fragment of structural proteins that drives its own replacement. Pentapeptide-3 delivers this signal without lipid modification, relying on aqueous diffusion rather than membrane partitioning for dermal delivery.
Pentapeptide-3 vs. Palmitoyl Pentapeptide-4
The palmitoylated version (Matrixyl) adds a C16 fatty acid to the N-terminus of KTTKS, improving skin penetration through lipid bilayer interaction. Pentapeptide-3 lacks this modification and is therefore fully water-soluble, making it the preferred choice for aqueous-only systems such as toners, mists, hydrogel masks, and water-gel serums where incorporating a lipopeptide would compromise product clarity or texture. In emulsion systems, formulators often combine both forms: the palmitoylated version in the oil phase and Pentapeptide-3 in the aqueous phase for dual-route delivery.
Formulation Guidelines
Incorporate Pentapeptide-3 at 50-200 ppm in the aqueous phase. The peptide dissolves readily in water and glycol-water blends. Optimal pH range is 5.0-7.0. Stable at processing temperatures up to 40 degrees C. Compatible with hyaluronic acid, niacinamide, panthenol, and most non-ionic and amphoteric surfactants. Avoid combining with strong proteolytic enzymes (papain, bromelain) in leave-on products, as these may cleave the peptide bond during shelf life. For enhanced penetration in aqueous formulations, consider pairing with penetration enhancers like pentylene glycol or low-molecular-weight hyaluronic acid.
Applications
- Water-gel serums and clear aqueous treatments requiring no oil phase
- Hydrogel sheet masks and bio-cellulose masks for intensive firming
- Facial mists and toners delivering collagen-signal peptides throughout the day
- Dual-peptide emulsions combining Pentapeptide-3 (aqueous) with Matrixyl (oil phase)
- Body smoothing sprays targeting crepey skin on arms and legs
Quality and Supply from TCS NEXUS S.L.
TCS NEXUS S.L. supplies Pentapeptide-3 from Valencia, Spain with HPLC purity of 98% minimum. Each lot includes a certificate of analysis covering mass spectrometry identity, HPLC purity, peptide content, amino acid composition, and microbial limits. We maintain inventory for fast European dispatch and support orders from research-scale milligrams to production-scale kilograms. Regulatory documentation for EU Cosmetics Regulation (EC) No 1223/2009 compliance is available on request.
Frequently Asked Questions
Is Pentapeptide-3 the same as Matrixyl?
No. Matrixyl is Palmitoyl Pentapeptide-4, which adds a C16 fatty acid chain to the KTTKS sequence. Pentapeptide-3 is the unmodified, water-soluble version of the same collagen fragment without lipid conjugation.
What concentration of Pentapeptide-3 is recommended?
Use 50-200 ppm in the finished product. Most commercial formulations target 100 ppm for measurable collagen-signalling activity balanced against raw material cost.
Can Pentapeptide-3 be used in clear aqueous formulations?
Yes. Its full water solubility makes it ideal for toners, mists, hydrogel masks, and water-gel serums where lipopeptide variants would cause turbidity or phase separation.
Technical Support and Samples
Request COA documents, sample availability, or support for custom synthesis.