Tyrosyltyrosylcysteine-Directed Synthesis of Chiral Cobalt Oxide Nanoparticles and Peptide Conformation Analysis

Abstract

Chiral inorganic nanomaterials have revealed opportunities in various fields owing to their strong light–matter interactions. In particular, chiral metal oxide nanomaterials that can control light and biochemical reactions have been highlighted due to their catalytic activity and biocompatibility. In this study, we present the synthesis of chiral cobalt oxide nanoparticles with a g-factor of 0.01 in the UV–visible region using l- and d-Tyr-Tyr-Cys ligands. The conformation of the Tyr-Tyr-Cys peptide on the nanoparticle surfaces was identified by 2D NMR spectroscopy analysis. In addition, the sequence effect of Tyr-Tyr-Cys developing chiral nanoparticles was analyzed. The revealed peptide structure, along with the experimental results, demonstrate the important role of the thiol group and carboxyl group of the Tyr-Tyr-Cys ligand in chirality evolution. Importantly, due to the magnetic properties of chiral cobalt oxide nanoparticles and their strong absorption in the UV region, the circular dichroism (CD) responses can be dramatically modulated under an external magnetic field.

Chirality at nanoscale for bioscience

“…The detailed bio-inspired chiral geometries of metallic nanostructures have been investigated by Ki Tae Nam's group. 85,86 The chiral geometries of nanostructures are considered the key factors in enhancing their chiroptic responses (Fig. 7E).…”

Chiral Nanostructures: New Twists

“…The most common origin of chiroptical activity in semiconductor NPs is the hybridization of the electronic states of chiral surface ligands and those of the semiconductor . Some of the typical nanostructures producing such effects include CdTe, CdSe, and CdS NPs and nanorods, − but chiral excitons can also be produced by small clusters of noble metals and nanocarbon. , Other organic or inorganic semiconductor materials obtained by enantioselective separation or de novo synthesis include ceramic nanostructures with excitonic states, such as Co 3 O 4 , perovskites, and porphyrin superstructures with π–π stacking …”

“…16 Some of the typical nanostructures producing such effects include CdTe, CdSe, and CdS NPs and nanorods, 17−19 but chiral excitons can also be produced by small clusters of noble metals 20 and nanocarbon. 16,21 Other organic or inorganic semiconductor materials obtained by enantioselective separation 21 or de novo synthesis 16 include ceramic nanostructures with excitonic states, such as Co 3 O 4 , 22 perovskites, 23 and porphyrin superstructures with π−π stacking. 24 Self-Assembled Chiral Nanostructures.…”

Inspirations of Cobalt Oxide Nanoparticle Based Anticancer Therapeutics

“…In short, the cobalt chloride, sodium citrate and Tyr-Tyr-Cys aqueous solution were mixed and stirred at room temperature for 30 min. Then NABH 4 was injected, followed by aging under stirring for 2 h at room temperature to obtain cobalt oxide nanoparticles [43].…”