Description

Hydroxy-dPEG®12-TFP ester, product number QBD-11345, is a medium-length (40 atoms, 46.2 Å), hydroxy-terminated, single molecular weight, discrete polyethylene glycol (dPEG®) compound functionalized with a 2,3,5,6-tetrafluorophenyl (TFP) ester for conjugation to primary and secondary amines. This product can be used for modification of amine-functionalized surfaces (e.g., silica, glass), modification of proteins and peptides at accessible amine sites on the molecules, the construction of discrete PEG dendrimers, and many other applications. The free hydroxy end of the dPEG® spacer can be functionalized for further reactions or left unmodified to increase hydrophilicity or modify the charge of conjugate molecules and surfaces.

Specifications

Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 2nd Edition, Elsevier Inc., Burlington, MA 01803, April, 2008 (ISBN-13: 978-0-12-370501-3; ISBN-10: 0-12-370501-0). Specifically see pp. 726-729 in his Chapter 18 on discrete PEG compounds for pegylation applications.

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See chapter 18, Discrete PEG Reagents, pp.787-821, for a full overview of the dPEG® products.

Description

S-acetyl-dPEG®12-OH, product number QBD-10939, contains an acetyl-protected thiol on a medium-length (36 atoms, 43.1 Å) hydroxy-terminated, discrete polyethylene glycol (dPEG®) linker. This product can be used to thiolate biomolecules.

Bioconjugation frequently employs thiolation because the reactions to install thiol groups on molecules or to react with molecules containing sulfhydryl groups are relatively simple and often chemoselective. The thioacetyl group is intended to install an acetyl-protected thiol onto biomolecules. While installing a protected thiol through a reaction between a carboxylic acid and a primary amine is widely popular in bioconjugation technology, it is not always possible or feasible. S-acetyl-dPEG®12-OH permits the installation of a protected thiol through a short, hydroxy-terminated discrete PEG® linker. Hydroxylamine hydrochloride (CAS number 5470-11-1) easily removes the S-acetyl group that protects the thiol, thus exposing the sulfhydryl for subsequent reaction. One application for S-acetyl-dPEG®12-OH is the modification of nucleic acids using phosphoramidite chemistry.

Specifications

Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.

Description

Thiol-dPEG®12-acid, product number QBD-10850, is a single molecular weight, discrete-length polyethylene glycol (dPEG®) PEGylation reagent. One end of the medium-length (39 atoms, 46.8 Å) dPEG® linker terminates in a sulfhydryl (thiol) group, while a propionic acid moiety terminates the opposite end. The thiol end of the molecule forms dative bonds with gold, thioether bonds with maleimide and bromoacetate groups, and disulfide bonds with other sulfhydryl groups. The propionic acid group reacts with amines to form amide bonds. Alternatively, if it is left unreacted, the propionic acid group provides a negative charge to the conjugated molecule or modified surface.

Numerous scientific publications attest to the benefits of Thiol-dPEG®12-acid, including the following applications:
Assaying protease by using fluorescence quenching with gold nanoparticles;
Enhancing transfection efficiency;
Modulating glucose transport with gold nanoparticles;
Developing multiplexed bioassays on semiconductor gold nanocrystals;
Developing spectroscopy applications; and,
Detecting cancer through a FRET-based, NIR-activated system that uses gold nanoparticles.

Specifications

Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.

Gold nanoparticle-based fluorescence quenching via metal coordination for assaying protease activity. Se Yeon Park, So Min Lee, Gae Baik, Kim and Young-Pil Kim. Gold Bull. 2012, 45 pp 213–219. October 25, 2012. DOI 10.1007/s13404-012-0070-9.

Systemically probing the bottom-up synthesis of AuPAMAM conjugates for enhanced transfection efficiency. Elizabeth R. Figueroa, Stephen Yan, Nicolette K. Chamberlain-Simon, Adam Y. Lin, Aaron E. Foster, and Rebekah A. Drezek. Journal of Nanobiotechnology. 2016, 14 (24). March 31, 2016. DOI: 10.1186/s12951-016-0178-9.

Modulating the Glucose Transport by Engineering Gold Nanoparticles. Sanjib Bhattacharyya, Krishna Kattel, and Franklin Kim. Journal of Nanomedicine and Biotherapeutic Discovery. 2016, 6 (1) pp 1-5. April 30, 2016. DOI: 10.4172/2155-983X.1000141.

Use of semiconductor nanocrystals to encode microbeads for multiplexed analysis of biological samples. Mikhail A Berestovoy, Regina S Bilan, Victor Krivenkov, Igor Nabiev, and Alyona Sukhanova. IOP Science. 2017, 784 (1) pp 1742-6596. March 15, 2017. DOI: 10.1088/1742-6596/784/1/012012.

Spectroscopy Based Approaches for Detection of Ions, Alpha-L-Fucosidase, and Singlet Oxygen. Eric Waidely. University of Miami Scholarly Repository. 2017, pp 1-113. May 3, 2017. http://scholarlyrepository.miami.edu/oa_dissertations/1842.

Near-Infrared-Activated Fluorescence Resonance Energy Transfer-Based Nanocomposite to Sense MMP2-Overexpressing Oral Cancer Cells. Yung-Chieh Chan, Ming-Hsien Chan, Chieh-Wei Chen, Ru-Shi Liu, Michael Hsiao, and Din Ping Tsai. ACS Omega. 2018,3 (2) pp. 1627-1634. February 8, 2018. DOI: 10.1021/acsomega.7b01494.

Signal enhancement of optical immunosensing by gold nanoparticles. Yuan Xintong. Nanyang Technological University, School of Material Science and Engineering Thesis for the degree of Master of Engineering. 2015, pp 1-74.

Biofunctionalized Polyelectrolyte Microcapsules Encoded with Fluorescent Semiconductor Nanocrystals for Highly Specific Targeting and Imaging of Cancer Cells. Galina Nifontova, Daria Kalenichenko, Maria Baryshnikova, Fernanda Ramos Gomes, Frauke Alves, Alexander Karaulov, Igor Nabiev, and Alyona Sukhanova. Advances on Applications of Optics and Photonics – Selected Papers from the 4th International Conference on Applications of Optics and Photonics, AOP2019. November 8, 2019. DOI: 10.3390/photonics6040117

NEW FRONTIERS FOR TRIPLE NEGATIVE BREAST CANCER DETECTION AND TREATMENT: FROM MECHANICAL BIOMARKERS TO SPECIFIC NANOPARTICLE ENTRY FOR ROBOTICALLY CONTROLLED LASER-INDUCED HYPERTHERMIA. Vanessa Uzonwanne. Worchester Polytechnic Institute. 2022. May 22, 2022.

SCORe: SARS-CoV-2 Omicron Variant RBD-Binding DNA Aptamer for Multiplexed Rapid Detection and Pseudovirus Neutralization. Lucy F. Yang, Nataly Kacherovsky, Joey Liang, Stephen J. Salipante, and Suzie H. Pun. Anal. Chem. 2022, 94, 37, 12683–12690. https://doi.org/10.1021/acs.analchem.2c01993

Description

Methoxytrityl-S-dPEG®12-acid, product number QBD-10846, permits the introduction of a protected thiol-dPEG® spacer/linker onto a molecule by reaction with a free amine. The dPEG®12 linker is functionalized with a methoxytrityl (Mmt)-protected thiol group one end and an amine-reactive propionic acid moiety on the other. The Mmt protecting group is easily removed under relatively mild conditions using dilute trifluoroacetic acid (TFA) with a scavenger.

QBD-10846 permits our customers to insert a medium-length (39 atoms, 46.8 Å) dPEG® into a peptide chain using familiar solid phase or solution phase chemistry. The dPEG® can be inserted at the N-terminus of a peptide chain or on any amino acid side chain with an exposed free amine. In addition, the dPEG® spacer can be used simply to provide additional distance in a synthetic construct where steric hindrance is a problem. The amphiphilic nature of dPEG® means that the construct will gain some degree of water solubility while remaining soluble in organic solvent. The Mmt protecting group removes relatively easily with a dilute solution of TFA that also contains a scavenger such as triethylsilane (TES) or triisopropylsilane (TIPS). Once the thiol group is deprotected, it can be reacted with another thiol to form a disulfide bond or with any thiol-reactive group such as maleimide, bromoacetamide, alkene (thiol-ene reaction) or alkyne (thiol-yne reaction).

Upon activation, Methoxytrityl-S-dPEG®12-acid reacts with any free amine, whether on a peptide, surface, or other molecule. This allows for a broad range of applications where this product can be employed to convert an amine to a thiol.

Specifications

Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.

Gold Nanoparticles Functionalized with Peptides for Specific Affinity Aggregation Assays of Estrogen Receptors and Their Agonists. Yoshiyuki Takatsuji, Shinya Ikeno and Tetsuya Haruyama. Sensors. 2012, 12 (4), pp 4952-4961. April 18, 2012. DOI: 10.3390/s120404952.

Description

m-dPEG®12-Lipoamide, product number QBD-10801, is a medium-length (46 atoms), amphiphilic, methyl-terminated, monodisperse PEG product functionalized with lipoic acid and designed to modify metal surfaces such as gold or silver. The primary application of this product is the stable passivation of metal surfaces through the use of lipoic acid, which forms two dative bonds with gold or silver, conjugated to a short, monodispersed PEG spacer. Because the terminal dithiolane unit forms two dative bonds with metals, it is consequently more stable on the metal surface than comparable compounds containing a single sulfhydryl group that can create a dative bond. The amphiphilic, non-antigenic, monodispersed PEG spacer imparts water solubility to and increases the hydrodynamic volume of conjugated molecules and surfaces.

m-dPEG®12-lipoamide was designed for stable passivation of gold or silver surfaces. For useful surface coating, it may prove helpful to create a mixed layer consisting of m-dPEG®12-lipoamide and another, longer dPEG® product with a lipoamido group on one end and reactive, affinity, or other functional groups on the opposite end. Thus, the shorter m-dPEG®12-lipoamide will form a uniform coating of methyl-terminated PEG above the metal surface, and the longer dPEG® product will rise above the dPEG® coating intermittently throughout the surface layer.

Specifications

Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 2nd Edition, Elsevier Inc., Burlington, MA 01803, April, 2008 (ISBN-13: 978-0-12-370501-3; ISBN-10: 0-12-370501-0), pp. 188-190, 458-497, 924-935.

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.

Self-Assembled Quantum Dot-Sensitized Multivalent DNA Photonic Wires. Kelly Boeneman, Duane E. Prasuhn, Juan B. Blanco-Canosa, Philip E. Dawson, Joseph S. Melinger, Mario Ancona, Michael H. Stewart, Kimihiro Susumu, Alan Huston, and Igor L. Medintz. J. Am. Chem. Soc., 2010, 132 (51), pp 18177–18190 December 8, 2010. DOI: 10.1021/ja106465x.

PEGylated Luminescent Gold Nanoclusters: Synthesis, Characterization, Bioconjugation, and Application to Oneand Two-Photon Cellular Imaging. Eunkeu Oh, Fredrik Fatemi, Marc Currie, James B. Delehanty, Thomas Pons, Alexandra Fragola, Sandrine L´evˆeque-Fort, Ramasis Goswami, Kimihiro Susumu, Alan L. Huston, and Igor L. Medintz. Particle & Particle Systems Characterization 2013, (30), pp 1-13. February 5, 2013. DOI: 10.1002/ppsc.201200140.

Gastrointestinal Bioavailability of 2.0 nm Diameter Gold Nanoparticles. Candice A. Smith, Carrie A. Simpson, Ganghyeok Kim, Carly J. Carter, and Daniel L. Feldheim. ACS Nano. 2013, 7 (5) pp 3991–3996. April 21, 2013. DOI: 10.1021/nn305930e.

Description

m-dPEG®12-thiol, product number QBD-10794, is a medium-length (38 atoms) monodisperse PEGylation reagent designed to modify gold and silver surfaces or biomolecules that contain free, surface-accessible thiols. One end of the spacer terminates with a methyl group, while the other end terminates with a sulfhydryl. The sulfhydryl group forms dative bonds with gold or silver, disulfides with free thiols, and thioether bonds with maleimide and bromoacetate groups.

This product is useful for the passivation of gold or silver surfaces. The hydrophilic, non-immunogenic dPEG® spacer eliminates non-specific interactions with the metal surfaces.

If reacted with free thiols on biomolecules, m-dPEG®12-thiol forms disulfide bonds. Moreover, the resulting conjugates display improved water solubility and increased hydrodynamic volume. Furthermore, conjugation of this product with biomolecules potentially reduces or eliminates non-specific interactions and immunogenicity.

Specifications

Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.

Description

t-boc-N-amido-dPEG®12-acid, product number QBD-10760, is composed of a boc-protected primary amine and a propionic acid group on opposite ends of a medium-length (40 atoms), single molecular weight, discrete PEG (dPEG®) linker. Designed for use in Boc-based peptide chemical synthesis, t-boc-N-amido-dPEG®12-acid can be used to insert a discrete PEG linker/spacer at the N-terminus of a peptide chain or to add a dPEG® onto the side chain of an amino acid such as lysine or ornithine. Insertion of t-boc-N-amido-dPEG®12-acid at the N-terminus of a peptide allows the creation of a flexible, hydrophilic bridge to the C-terminus of another peptide. The Boc protecting group cleaves easily under acidic conditions with, for example, TFA. This compound can also be used to modify amine-functionalized surfaces to passivate them with a hydrophilic spacer. Removal of the boc group with acid allows for functionalization of the surface with peptides, proteins, or small molecules.

Specifications

Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.

Description

m-dPEG®12-DBCO, product number QBD-10596, is a methoxy-terminated, discrete polyethylene glycol (dPEG®) click chemistry reagent designed for chemical modification of surfaces through strain-promoted azide-alkyne cycloaddition (SPAAC). From the terminal methyl group to the reactive site on the dibenzylcyclooctyne (DBCO) group, the dPEG® spacer is 39 atoms long.

DBCO was designed for bio-orthogonal click chemistry applications using SPAAC, also known as copper-free click chemistry, which was developed by Carolyn Bertozzi and colleagues to avoid the potential toxicity of Cu(I) that is used in Copper(I)-Promoted Azide Alkyne Cycloaddition (CuAAC) discovered by K. Barry Sharpless and colleagues. The dPEG® spacer differs from traditional PEG spacers and linkers in that it consists of a single molecular weight and chain length of PEG (i.e., it is monodispersed), which simplifies analysis of conjugates made with this compound.

Potential uses for this product include modifying alkyne-functionalized surfaces and peptides and proteins containing alkyne-functionalized amino acid side chains.

Specifications

Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 2nd Edition, Elsevier Inc., Burlington, MA 01803, April, 2008 (ISBN-13: 978-0-12-370501-3; ISBN-10: 0-12-370501-0). Specifically see pp. 726-729 in his Chapter 18 on discrete PEG compounds for pegylation applications.

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See chapter 18, Discrete PEG Reagents, pp.787-821, for a full overview of the dPEG® products.

Description

m-dPEG®12-azide, product number QBD-10536, also known as azido-m-dPEG®12, is a monodispersed PEG product used in click chemistry applications. A non-reactive, charge-neutral methyl group and an alkyne-reactive azido group, respectively, terminate the two ends of the medium-length (38 atoms), single molecular weight, discrete PEG (dPEG®) spacer. Both metal-catalyzed (Cu(I), Ru) azide-alkyne cycloaddition (CuAAC, RuAAC) and strain-promoted azide-alkyne cycloaddition (SPAAC) work with this product. Possible click chemistry-based applications for this product include the construction of dendrimers and hydrogels and the modification of alkyne-functionalized surfaces or biomolecules containing alkyne groups.

Specifications

Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.

Description

Azido-dPEG®12-acid, product number QBD-10513, is a click chemistry crosslinking reagent functionalized with an azide group and a propionic acid group on opposite ends of a linear spacer. A water-soluble, medium-length (40 atoms), single molecular weight, discrete polyethylene glycol (dPEG®) spacer separates the two groups. The azide moiety reacts in copper(I)-catalyzed, ruthenium-catalyzed, and strain promoted azide-alkyne cycloadditions (CuAAC, RuAAC, and SPAAC, respectively). Alternatively, the azide functions as a masked amine. In this role, the carboxylic acid end of the molecule must couple with an amine to form an amide bond. The azide group is then reduced to a primary amine to permit crosslinking with a carboxylic acid group. The propionic acid moiety can be coupled to a primary or secondary amine by an acylation reaction.

The carboxylic acid group of Azido-dPEG®12-acid can be coupled directly to a free amine using EDC or some other carbodiimide. Also, forming the active ester of the acid using N-hydroxysuccinimide (NHS) or 2,3,5,6-tetrafluorophenol (TFP) before reacting with free amines is a useful course of action.

Specifications

Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.