We developed an integrated proteomics approach using a chemically functionalized gold nanoparticle (AuNP) as a novel probe for affinity purification to analyze a large protein complex in vivo. We then applied this approach to globally map the transcriptional activation complex of the estrogen response element (ERE). This approach was designated as quantitative nanoproteomics for protein complexes (QNanoPX). In this approach, the positive AuNP-ERE probes were functionalized with polyethylene glycol (PEG), and the consensus sequence of ERE and negative AuNP-PEG probes were functionalized with PEG without the ERE via a thiolated self-assembly monolayer technique. The AuNP-ERE probe had substantially low nonspecific binding and high solubility, which resulted in a 20-fold enrichment of the factor compared with gel beads. In addition, the surface-only binding allows the probe to capture a large protein complex without any restrictions due to pore size. The affinity purification method was combined with MS-based quantitative proteomics and statistical methods to reveal the components of the ERE complex in MCF-7 cells and to identify those components within the complex that were altered by the presence of 17␤-estradiol (E2).

Kinetic resolution of nitroallylic amines was established using chiral α,α-l-diphenylprolinol silyl ether auxiliary through isolation of the dihydrooxazine N-oxide intermediates. Further hydrolyzing the resting states provided tetrahydropyridines in high chemical yields and high to excellent stereoselectivities (up to >20:1 dr and 98% ee). A detailed mechanistic explanation for stereoselective protonation in the dihydrooxazine was probed computationally. In addition, the probable intermediates in α-halogenation of aldehydes (masked with enamines) were isolated to provide crystallographic evidence.