Thermo Scientific Pierce MA(PEG)n Compounds are methyl- and amine-terminated polyethylene glycol reagents, where n equals 4 to 24 PEG units, that are useful for a variety of surface-modification and molecule-pegylation applications.
MA(PEG)n is the abbreviation for a set of compounds having polyethylene glycol (PEG) spacers and terminal methyl (-CH3) and amino (-NH2) groups. The unbranched, hydrophilic, discrete-length molecules have the form Methyl-PEGn-Amine, where the subscript "n" denotes 4, 8, 12, or 24 ethylene glycol units. The terminal primary amine of each compound provides a specific target for crosslinking and other conjugation methods, making these compounds useful as PEGylation reagents.
- Fully characterized PEGylation reagents with defined PEG chain lengths; molecules of discrete molecular weights for consistency of performance in protein-modification applications
- Provided as a series of 4, 8, 12 and 24 ethylene glycol units, enabling modification procedures to be optimized for a specific application while retaining all the benefits associated with protein PEGylation
- PEG spacer provides unique advantages, including increased stability, reduced tendency toward aggregation and reduced immunogenicity
- Allows site-specific labeling of primary amines or carboxyl groups on proteins or surfaces
- Easy-to-follow instructions increase the likelihood of a successful outcome
Methods of Covalent Attachment:
- Conjugate to carboxyl groups using EDC
- Crosslink to primary amines using DSS, BS(PEG)n or other NHS ester reagent
- Crosslink to sulfhydryl groups using Sulfo-SMCC or SM(PEG)n reagent
- Attach to oxidized carbohydrate groups (aldehydes) by reductive amination
- Amino-PEG 600
- Amine-modified PEG
Applications of PEGylation:
- PEGylate carboxylate or amine surfaces
- Add inert mass to proteins, immunogens, drug compounds and probes
- Improve solubility (decrease aggregation) of proteins or peptides without affecting function
- Protect proteins from proteolysis
Why PEGylate a protein or peptide?
Methyl-capped PEG-containing reagents have been used to modify proteins to provide specific advantages. Protein PEGylation can improve the stability of the modified protein, protect it from proteolytic digestion, increase its half life in a biological application, mask it from causing an immunogenic response, decrease its antigenicity or potential toxicity, improve its solubility, diminish the potential for aggregation, and minimize interference for both in vitro and in vivo applications. Polyethylene glycol, also called polyethylene oxide (PEO), has these effects because it is nontoxic, nonimmunogenic, hydrophilic, water soluble and highly flexible.
Advantages of Discrete-length Polyethylene Glycol Compounds:
These reagents are specially synthesized, resulting in homogeneous compounds of defined molecular weight, characterized by discrete chain lengths, providing a greater ability to optimize and characterize surface protein modifications. Typical preparations of PEG compounds are a heterogeneous mixtures composed of a distribution of chain lengths with a specified average molecular weight or approximate number of PEG subunits.
- Hermanson, G.T. (2008). Bioconjugate Techniques, Academic Press (Part No. 20036)
- Harris, J. M. and Zalipsky, S. Eds (1997). Poly(ethylene glycol), Chemistry and Biological Applications, ACS Symposium Series, 680.
- Harris, J. M. and Kozlowski, A. (2001). Improvements in protein PEGylation: pegylated interferons for treatment of hepatitis C. J. Control Release 72, 217-224.
- Veronese, F. and Harris, J.M. Eds. (2002). Peptide and protein PEGylation. Advanced Drug Delivery Review 54(4), 453-609.
Carboxyl-PEG-Amine Compounds, CA(PEG)n
Other Kinds of PEGylation Reagents