Polylysine

The alpha-linked polylysine variant (poly-L-lysine), a cationic homopolymer of L-lysine linked through alpha-amino and alpha-carboxyl groups. Distinct from the bacterially fermented epsilon-polylysine (catalog id 25999) in linkage geometry and production route.

White to off-white powder. Water-soluble. Functions as both a food preservative and a biomedical cell-culture coating material; commercial grades span a wide molecular weight range to suit different applications.

We supply food-grade and pharmaceutical-grade Polylysine from manufacturers in China holding ISO and other certifications relevant to the product and production.

Common market grades include Low Molecular Weight (1,000 to 30,000 Da, food preservation and antimicrobial coating), Medium Molecular Weight (30,000 to 70,000 Da, cell culture surface coating), and High Molecular Weight (70,000 to 300,000 Da, specialty biomedical applications).

Bulk and reduced-MOQ shipments. Batch-level COA covering polylysine content, molecular weight, loss on drying, heavy metals, and microbiology.

Polylysine in its alpha-linked form (poly-L-lysine) is typically produced by chemical polymerization or solid-phase peptide synthesis. The product is structurally distinct from the bacterially fermented epsilon-polylysine, in which the peptide bonds connect the epsilon-amino group of one lysine residue to the alpha-carboxyl of the next. The alpha-linked form is the conventional protein-style polymer with linear poly-amide backbone.

Both alpha- and epsilon-polylysines are polycationic polymers that interact electrostatically with negatively charged components of microbial cell walls and membranes, compromising structural integrity and causing cell death. Effective use levels for food preservation are typically 10 to 200 ppm.

The alpha-linked form is recognized for cell-culture surface coating applications, where it promotes adhesion of poorly adhesive cells (neurons, certain primary cell lines) by providing positively charged surface chemistry that interacts with negatively charged cell membranes.

In food applications, polylysine preparations are evaluated for preservation of moisture-rich prepared foods, dressings, and beverages. Some commercial preparations labeled simply 'Polylysine' contain or are composed of epsilon-polylysine; specification documentation should be reviewed to confirm linkage type for sensitive applications.

Strategic positioning combines food preservation (the largest volume application), biotechnology and laboratory reagent supply (the highest unit value), and specialty biomedical and pharmaceutical research applications.

• Food preservation: antimicrobial against bacteria, yeasts, and molds
• Cell culture surface coating in biotechnology and tissue culture laboratories
• Pharmaceutical gene-delivery and transfection reagent
• Biomedical coating material for diagnostic and research devices
• Antimicrobial film and food packaging applications
• Agricultural antimicrobial formulations
• Cosmetic and personal-care preservation systems
• Research reagent for microbiology and biochemistry