Cellular oxido-reductive proteins of Chlamydomonas reinhardtii control the biosynthesis of silver nanoparticles

Abstract

BackgroundElucidation of molecular mechanism of silver nanoparticles (SNPs) biosynthesis is important to control its size, shape and monodispersity. The evaluation of molecular mechanism of biosynthesis of SNPs is of prime importance for the commercialization and methodology development for controlling the shape and size (uniform distribution) of SNPs. The unicellular algae Chlamydomonas reinhardtii was exploited as a model system to elucidate the role of cellular proteins in SNPs biosynthesis.ResultsThe C. reinhardtii cell free extract (in vitro) and in vivo cells mediated synthesis of silver nanoparticles reveals SNPs of size range 5 ± 1 to 15 ± 2 nm and 5 ± 1 to 35 ± 5 nm respectively. In vivo biosynthesized SNPs were localized in the peripheral cytoplasm and at one side of flagella root, the site of pathway of ATP transport and its synthesis related enzymes. This provides an evidence for the involvement of oxidoreductive proteins in biosynthesis and stabilization of SNPs. Alteration in size distribution and decrease of synthesis rate of SNPs in protein-depleted fractions confirmed the involvement of cellular proteins in SNPs biosynthesis. Spectroscopic and SDS-PAGE analysis indicate the association of various proteins on C. reinhardtii mediated in vivo and in vitro biosynthesized SNPs. We have identified various cellular proteins associated with biosynthesized (in vivo and in vitro) SNPs by using MALDI-MS-MS, like ATP synthase, superoxide dismutase, carbonic anhydrase, ferredoxin-NADP+ reductase, histone etc. However, these proteins were not associated on the incubation of pre-synthesized silver nanoparticles in vitro.ConclusionPresent study provides the indication of involvement of molecular machinery and various cellular proteins in the biosynthesis of silver nanoparticles. In this report, the study is mainly focused towards understanding the role of diverse cellular protein in the synthesis and capping of silver nanoparticles using C. reinhardtii as a model system.

Biosynthesis and characterization of cadmium sulfide nanoparticles – An emphasis of zeta potential behavior due to capping

“…Cellular proteins attached on CdS NPs were removed by heating at 95 C for 5 min in Laemmli buffer. Separation of bare CdS NPs by centrifugation was done at 6000 rpm [35,36].…”

Engineering tailored nanoparticles with microbes: quo vadis?

“…Barwal et al . exploited unicellular algae Chlamydomonas reinhardtii as a model system to elucidate the role of cellular proteins in Ag nanoparticles biosynthesis . Also, Spirulina platensis has been used to synthesize Ag and Au nanoparticles with sizes ranging from 7–16 nm to 6–10 nm, respectively .…”

Experimental probes of silver metal nanoparticle formation kinetics: Comparing indirect versus more direct methods

“…UV-visible spectroscopy has been more commonly used to follow the change in surface plasmon resonance during gold and/or silver nanoparticle formation, and corresponding kinetic curves have been reported in the literature. [15][16][17][18][19][20][21][22][23] However, this method amounts in essence to an "indirect" probe of the chemical kinetics involved; also, surface plasmon resonance properties such as absorbance maximum and extinction coefficient vary with nanoparticle size. [24][25][26][27][28][29][30][31] It is important, therefore, to gather more information to confirm the effectiveness of the plasmon-based method for kinetic analysis 32 and to examine how it compares to more "direct" probes that, instead, follow the concentration of metal ions.…”