Carbohydrate‐Encapsulated Gold Nanoparticles for Rapid Target‐Protein Identification and Binding‐Epitope Mapping

Abstract

Carbohydrate–lectin recognition plays important roles in cell–cell communication, proliferation, and differentiation. We report here a new approach of using a carbohydrate‐encapsulated gold nanoparticle (shown in purple) as an affinity probe for the efficient separation and enrichment of target proteins, and then protein identification and epitope mapping by MALDI‐TOF MS.

Globotriose‐Functionalized Gold Nanoparticles as Multivalent Probes for Shiga‐like Toxin

“…Compounds 1 and 2 [35] are P k antigens that contain a linker of two different lengths, and 1 and 2 were synthesized as we previously described, [38] with modifications, as shown in Scheme 1. Previously, we used lactoside 4 and galactosyl phosphite donor 5 to construct the P k trisaccharide derivative 6.…”

“…Notably, after capturing the target protein on the AuNP surface, the normally tedious desalting procedure before mass analysis can be simplified by washing the AuNP complex with water. [35] The P k -AuNP-captured B-Slt was resistant proteolysis by trypsin (data not shown). All of these results clearly demonstrated that P k -AuNP is a target-specific and effective nano-affinity probe.…”

“…[34] These experiments demonstrated that the binding of Con A to m-AuNP is enhanced dramatically (by~100-fold) compared with binding to free mannose. Also, we have explored the identification of a target protein from a protein mixture by using galactose and P k -coated AuNPs in combination with MALDI-TOF MS. [35] By using this nanoprobe-based mass spectrometry approach, the target lectin PA-IL was identified at femtomole concentrations, and its discontinuous binding epitopes were revealed…”

Introduction to Chemical Proteomics for Drug Discovery and Development

“…In particular, biomolecule-conjugated gold nanoparticles (AuNPs) are the most popular probes because of their advantages such as the readily assembling with thiolated molecules, the large area/volume ratio for investigating 3D interactions, and the ease of separation by centrifugation [14,15]. Recently, a new approach of using carbohydrate-encapsulated AuNP has been introduced [11]. This allows rapid mapping of carbohydrate-recognition peptide sequences in the target proteins.…”

Nanotechniques in proteomics: Current status, promises and challenges

“…Inset shows structure of multifunctional nanoparticle probe based on QDs where coordinating ligand, TOPO (tri-n-octylphosphate oxide) and amphiphilic polymer coating protect the core-shell CdSe-ZnS QDs. (e) Application of carbohydrate-encapsulated gold nanoparticle (c-Au NP) for targeting of protein analytes using nanoprobe-based affinity mass spectrometry (NBAMS); subsequent protein identification and epitope mapping performed using MALDI-TOF-TOF MS (modified from Chen et al, 2005). (f) Ultrasensitive protein detection by nanoparticle based bio-bar codes (modified from Nam et al, 2003) where gold nanoparticle (NP) probes and magnetic microparticle (MMP) probes sandwich the target protein to generate a complex with large ratio of bar code DNA to target protein.…”