Tunable Inhibition and Denaturation of α-Chymotrypsin with Amino Acid-Functionalized Gold Nanoparticles
摘要:
Water-soluble gold nanoparticles bearing diverse L-amino acid terminals have been fabricated to probe the effect of receptor surface on protein surface binding. The interaction of these nanoparticles with a-chymotrypsin (ChT) was investigated by activity assay, gel electrophoresis, zeta-potential, circular dichroism, and fluorescence spectroscopy. The results show that both electrostatic and hydrophobic interactions between the hydrophobic patches of receptors and the protein contribute to the stability of the complex. The microscopic binding constants for these receptor-protein systems are 10(6)-10(7) M-1, with the capacity of the nanoparticle receptors to bind proteins determined by both their surface area and their surface charge density. Furthermore, it is found that the hydrophilic side chains destabilize the ChT structure through either competitive hydrogen bonding or breakage of salt bridges, whereas denaturation was much slower with hydrophobic amino acid side chains. Significantly, correlation between the hydrophobicity index of amino acid side chains and the binding affinity and denaturation rates was observed.
Arrays for the Combinatorial Exploration of Cell Adhesion
摘要:
A new method for the fabrication of arrays of self-assembled monolayers (SAMs) of alkane thiols (ATs) on gold to combinatorially assay surfaces for cell adhesion is reported. A fluorous SAM, which is both cytophobic and solvophobic, was used as the background between the array features. The resulting solvophobic background permits the application of an assembly after conjugation strategy for fabrication. SAMs containing mixtures of ATs and peptide-terminated ATs were generated. Multiple cell types demonstrated differential and specific binding to these surfaces. Additionally, pluripotent human embryonic stem cells proliferated on surfaces generated by this method.
Isomeric Control of Protein Recognition with Amino Acid- and Dipeptide-Functionalized Gold Nanoparticles
作者:Chang-Cheng You、Sarit S. Agasti、Vincent M. Rotello
DOI:10.1002/chem.200701234
日期:2008.1
Amino acid and dipeptide-functionalizedgoldnanoparticles (NPs) possessing L/D-leucine and/or L/D-phenylalanine residues have been constructed in order to target the surfaces of alpha-chymotrypsin (ChT) and cytochrome c (CytC). Isothermal titration calorimetry (ITC) was conducted to evaluate the binding thermodynamics and selectivity of these NP-protein interactions. The chirality of the NP end-groups
Direct photopatterning of light-activated gold nanoparticles
作者:Chandramouleeswaran Subramani、Xi Yu、Sarit. S. Agasti、Bradley Duncan、Serkan Eymur、Murat Tonga、Vincent M. Rotello
DOI:10.1039/c1jm11035g
日期:——
Photoactivatable gold NPs were patterned viaphotolithography. In this approach, charge reversal of the ligands on NPs upon UV irradiation induces crosslinking to generate stable NP patterns.
Acylsulfonamide-Functionalized Zwitterionic Gold Nanoparticles for Enhanced Cellular Uptake at Tumor pH
作者:Tsukasa Mizuhara、Krishnendu Saha、Daniel F. Moyano、Chang Soo Kim、Bo Yan、Young-Kwan Kim、Vincent M. Rotello
DOI:10.1002/anie.201411615
日期:2015.5.26
A nanoparticle design featuring pH‐responsive alkoxyphenyl acylsulfonamide ligands is reported herein. As a result of ligand structure, this nanoparticle is neutral at pH 7.4, becoming positively charged at tumorpH (<6.5). The particle uptake and cytotoxicity increase over this pH range. This pH‐controlled uptake and toxicity makes this particle a promising tool for tumor selective therapy.
Regulation of α-chymotrypsin activity on the surface of substrate-functionalized gold nanoparticles
作者:Chang-Cheng You、Rochelle R. Arvizo、Vincent M. Rotello
DOI:10.1039/b605508g
日期:——
A gold nanoparticle functionalized with substrates for α-chymotrypsin was fabricated to afford an enzyme modulator that exhibited enzyme-specific activation coupled with general inhibition of other proteases.