Lipoamido-dPEG®₄-TFP ester




Lipoamido-dPEG®4-TFP ester, product number 10641, is a monodispersed PEG crosslinker. From the disulfide bond in the lipoic acid ring to the carbonyl carbon adjacent to the 2,3,5,6-tetrafluorophenol (TFP) ester, the distance is 24 atoms (28.0 Å). The TFP ester forms amide bonds with free amines, while the lipoic acid group forms coordinate covalent (i.e., dative) bonds with metals, especially gold and silver. Applications for this product include creating self-assembled monolayers (SAMs) on metal surfaces and crosslinking and immobilizing peptides and proteins to the surfaces of metal nanoparticles.

Discrete PEG Products

Traditional PEG products are dispersed polymers that contain complex mixtures of different PEG chain lengths and molecular weights in a Poisson distribution. Analysis of conjugates made with these products can be time consuming and expensive.

Quanta BioDesign, Ltd. manufactures and sells monodispersed PEG products under the dPEG® tradename. From our founding, we have pioneered the synthesis of highly pure, monodispersed PEG.

Our dPEG® products are different from traditional PEGylation products. First, all of our products are monodispersed. Each product contains a single PEG product with a discrete chain length and molecular weight. Second, instead of purifying our dPEG® products from a polymer mixture, we synthesize them from highly pure starting materials, building them stepwise until we achieve the desired dPEG® spacer or linker. Our processes are scalable from milligrams to multiple kilograms.

Learn more!

What is dPEG®?

Frequently Asked Questions (about dPEG® products)

Lipoic Acid-containing dPEG® Products

Lipoic acid, also known as alpha-lipoic acid, α-lipoic acid, and thioctic acid, consists of a five-membered ring containing a disulfide attached to a pentanoic acid group. As a naturally occurring antioxidant, lipoic acid functions as a cofactor in several enzyme systems.

Lipoic acid is a bidentate thiol ligand that forms two stable dative bonds per lipoic acid group with gold, silver, and other metals. These dative bonds form with oxidized lipoic acid or reduced dihydrolipoic acid (DHLA). Because it forms two dative bonds on metal surfaces, lipoic acid is more stable than PEGylation reagents containing a single thiol. This increased stability prevents lipoic-acid-functionalized dPEG® products from being oxidized off the metal surface.

Using Lipoamido-dPEG®4-TFP ester

TFP esters react more readily with amines and possess better hydrolytic stability than N-hydroxysuccinimide (NHS). The superiority of PEG-TFP esters over NHS esters is documented in the scientific literature and by Quanta BioDesign’s in-house research.

When using this product, it is typical to conjugate the carboxyl end of the dPEG® to an amine to form an amide bond before forming a dative bond between a metal surface and the lipoic acid moiety of Lipoamido-dPEG®4-TFP ester. The TFP ester reacts optimally at pH 7.5 – 8.0, but it will also react with amines at pH values above and below this range.

Lipoamido-dPEG®4-TFP ester has limited solubility in water or aqueous buffer. We recommend using dry (over 3 Å molecular sieves) water-miscible solvents such as N, N-dimethylacetamide (DMAC) or acetonitrile to form a stock solution that can be added to aqueous buffer to carry out the reaction.

The lipoic acid group forms dative bonds with metals with or without reduction to DHLA. If reduction to DHLA is preferred, Tris(2-carboxyethyl)phosphine (TCEP) will reduce lipoic acid to DHLA rapidly.

Bulk Quantities Are Available

If you need a larger quantity of Lipoamido-dPEG®4-TFP ester than our standard package sizes, please contact us for a quote. Our commercial capabilities permit us to manufacture this product at any scale that you need.

Buy It Now!

Our dPEG® products are different from conventional PEGylation reagents. To discover the dPEG® difference, please click the “Add to Cart” button now.





Additional information

Weight .5 oz
Dimensions .75 × .75 × 2 in