Thermo Scientific Pierce ML(PEG)4, or methyl-PEG4-lipoamide, is a methyl- and bidentate thiol-terminated compound that contains a 4-unit polyethylene glycol (PEG) spacer and is used to modify quantum dots, silver and gold surfaces and magnetic particles.
ML(PEG)4 is a bidentate thiol-terminated and carboxylic acid pegylation reagent. The PEG compound has a defined molecular weight and spacer length and is useful for modifying surfaces such quantum dots, self-assembled monolayers and magnetic particles. Functionalization of solid surfaces with polyethylene glycol spacers such as this one significantly reduces nonspecific protein binding.
- Metal-binding – terminal bidentate thiol reacts spontaneously with silver, gold and other metal surfaces to form strong dative bonds
- Methyl – terminal methyl group is unreactive, the primary function of this compound being to coat quantum dot and other surfaces to reduce nonspecific binding in assays
- Polyethylene glycol – PEG groups are flexible, non-immunogenic, hydrophilic, and significantly reduce nonspecific binding of surfaces for protein methods
- Spacer arm – four-unit PEG spacer makes compound nearly 24 angstroms long
Chemical structure and properties of ML(PEG)4:
- Alternative name: Methyl-PEG4-Lipoamide
- Chemical name: 5-(1,2-dithiolan-3-yl)-N-(2,5,8,11-tetraoxatridecan-13-yl)pentanamide
- Chemical formula: C17H33NO5S2
- Molecular weight: 395.58
- Spacer arm: 23.6 angstroms
- Form: clear to pale yellow liquid
- Solubility: dissolve in DMSO or DMF for use
The use of ML(PEG)4 with CL(PEG)12 in surface modification can form a hydrophilic “lawn” of methyl ether-terminated PEGs with periodic exposed carboxy -containing PEGs. The exposed carboxylic acid groups can be coupled to affinity ligands using the carbodiimide coupling reaction with EDC and sulfo-NHS.
|Modification of metal surfaces with ML(PEG)4 and CL(PEG)12 pegylation reagents.
Typical PEG reagents contain heterogeneous mixtures of different PEG chain lengths; however, our PEG reagents are homogenous compounds of defined molecular weight and spacer length, providing precision in optimizing modification applications.
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- Bentzen, E.L., et al. (2005). Surface modification to reduce non-specific binding of quantum dots in live cell assays. Bioconjugate Chem 16:1488-94.
- Lin, P-C., et al. (2006). Ethylene glycol-protected magnetic nanoparticles for a multiplexed immunoassay in human plasma. Small 2(4):485-9.
- Zheng, M., et al. (2003). Ethylene glycol monolayer protected nanoparticles for eliminating nonspecific binding with biological molecules. J Am Chem Soc 125:7790-1.
- Verma, A. and Rotello, V.M. (2005). Surface recognition of biomacromolecules using nanoparticle receptors. Chem Commun 3:303-12.
- Kidambi, S., et al. (2004). Selective depositions on polyelectrolyte multilayers: self-assembled monolayers of m-dPEG acid as molecular template. J Am Chem Soc 126:4697-03.
Protein PEGylation technical guide (and PEG reagent selection guide)