ATP synthesis in the energy metabolism pathway: a new perspective for manipulating CdSe quantum dots biosynthesized in <em>Saccharomyces cerevisiae</em>

Abstract

Due to a growing trend in their biomedical application, biosynthesized nanomaterials are of great interest to researchers nowadays with their biocompatible, low-energy consumption, economic, and tunable characteristics. It is important to understand the mechanism of biosynthesis in order to achieve more efficient applications. Since there are only rare studies on the influences of cellular energy levels on biosynthesis, the influence of energy is often overlooked. Through determination of the intracellular ATP concentrations during the biosynthesis process, significant changes were observed. In addition, ATP synthesis deficiency caused great decreases in quantum dots (QDs) biosynthesis in the Δ atp1 , Δ atp2 , Δ atp14 , and Δ atp17 strains. With inductively coupled plasma-atomic emission spectrometry and atomic absorption spectroscopy analyses, it was found that ATP affected the accumulation of the seleno-precursor and helped with the uptake of Cd and the formation of QDs. We successfully enhanced the fluorescence intensity 1.5 or 2 times through genetic modification to increase ATP or SeAM (the seleno analog of S -adenosylmethionine, the product that would accumulate when ATP is accrued). This work explains the mechanism for the correlation of the cellular energy level and QDs biosynthesis in living cells, demonstrates control of the biosynthesis using this mechanism, and thus provides a new manipulation strategy for the biosynthesis of other nanomaterials to widen their applications.

Artificially regulated synthesis of nanocrystals in live cells

“…The downstream metabolites of hydrogen selenide are multiple organoselenium compounds, including selenocysteine (SeCys), L-selenocystine [(Cys-Se) 2 ] and selenomethionine (SeMet) (Fig. 2 ); this has been confirmed in Saccharomyces cerevisiae cells by high-performance liquid chromatography coupled with inductively coupled plasma mass spectrometry analysis and the use of selective selenol probes [ 5 , 8 , 9 ]. The consumption of GSH induces the upregulation of the expression of cysteine-synthesis-related genes, which can promote the conversion of SeMet to SeCys [ 10 ].…”

“…Unlike the conventional chemical synthesis, which mostly occurs at ∼200–300°C, ARLCS proceeds in ambient physiological conditions. Thus, it is of significance to investigate the underlying energy driving the reactions [ 8 , 14 ]. ATP is the commonest direct energy resource in live cells.…”

“…ATP is the commonest direct energy resource in live cells. By introducing several ATP-synthesis-deficient strains of yeast cells, ATP is proved to be a pivotal energy resource in ARLCS; it participates in the accumulation of Se-containing precursors, the uptake of Cd and the formation of QDs [ 8 ]. The yield of live-cell-synthesized QDs can be enhanced 2-fold in genetically modified cells in which the ATP level is elevated [ 8 ].…”

“…The ‘space–time coupling ARLCS strategy’ was first proposed to account for the synthesis of CdSe QDs in S. cerevisiae in 2009 [ 5 , 8 , 26 , 28 , 39 , 40 ], and it has been expanded to the synthesis of various nanocrystals, such as CdTe, ZnSe, CuSe and Te nanorods, in other cell types including Staphylococcus aureus [ 41 – 43 ], Fusarium oxysporum [ 44 ], E. coli [ 45 ], S. oneidensis [ 11 , 15 , 46 ], Bacillus licheniformis [ 47 ], B acillus amyloliquefaciens [ 48 ], Rhodotorula mucilaginosa [ 49 ], Candida utilis [ 50 ], mammalian cells [ 51 ], Tetrahymena pyriformis [ 52 , 53 ], Caenorhabditis elegans [ 54 ] and earthworms [ 38 , 55 ], by easily altering the raw chemicals fed to the cells (Fig. 1 ).…”

Microbial Nanotechnology: Challenges and Prospects for Green Biocatalytic Synthesis of Nanoscale Materials for Sensoristic and Biomedical Applications

“…The availability of microorganism genome sequences could considerably increase the range of possibilities in genetic manipulation of microorganism to implement the nanoparticles biosynthesis and the in vivo tuning of nanoparticle characteristics. A recent example has come from the study of Zhang et al (2017), which showed how CdSe quantum dots biosynthesis can be improved through genetic modification of the ATP metabolism pathway in yeast S. cerevisiae [107]. Biotechnological approaches based on genetic engineering and recombinant technologies could allow the identification of sequences of gene involved in nanoparticle synthesis and a possible heterologous expression (i.e., controlled expression of one or more gene sequences in a host organism) to enhance nanomaterial production efficiency [91].…”