Formation of toxic amyloid structures is believed to be associated with various late-onset neurodegenerative disorders such as Alzheimer's and Parkinson's diseases. The fact that many proteins in addition to those that are associated with clinical conditions have the potential to form amyloid fibrils in vitro provides opportunities for studying the fundamentals of protein aggregation and amyloid formation in model systems. Accordingly, considerable interest and effort has been directed toward developing small molecules to inhibit the formation of fibrillar assemblies and their associated toxicities. In the present study, we investigated the inhibitory effect of crocin and safranal, two principal components of saffron, on fibrillation of apo-alpha-lactalbumin (a-alpha-LA), used as a model protein, under amyloidogenic conditions. In the absence of any ligand, formation of soluble oligomers became evident after 18 h of incubation, followed by subsequent appearance of mature fibrils. Upon incubation with crocin or safranal, while transition phase to monomeric beta structures was not significantly affected, formation of soluble oligomers and following fibrillar assemblies were inhibited. While both safranal and crocin had the ability to bind to hydrophobic patches provided in the intermediate structures, and thereby inhibit protein aggregation, crocin was found more effective, possibly due to its simultaneous hydrophobic and hydrophilic character. Cell viability assay indicated that crocin could diminish toxicity while safranal act in reverse order.

Investigation of non-covalent interaction of hydrophobic surfaces with the protein G (PrG) is necessary due to their frequent utilization in immunosensors and ELISA. It has been confirmed that surfaces, including carbonous-nanostructures (CNS) could orient proteins for a better activation. Herein, PrG interaction with single-walled carbon nanotube (SWCNT) and graphene (Gra) nanostructures was studied by employing experimental and MD simulation techniques. It is confirmed that the PrG could adequately interact with both SWCNT and Gra and therefore fine dispersion for them was achieved in the media. Results indicated that even though SWCNT was loaded with more content of PrG in comparison with the Gra, the adsorption of the PrG on Gra did not induce significant changes in the IgG tendency. Several orientations of the PrG were adopted in the presence of SWCNT or Gra; however, SWCNT could block the PrG-FcR. Moreover, it was confirmed that SWCNT reduced the α-helical structure content in the PrG. Reduction of α-helical structure of the PrG and improper orientation of the PrG-SWCNT could remarkably decrease the PrG tendency to the Fc of the IgG. Importantly, the Gra could appropriately orient the PrG by both exposing the PrG-FcR and also by blocking the fragment of the PrG that had tendency to interact with Fab in IgG.

Today, crude oil is an important source of energy and environmental contamination due to the continued use of petroleum products is a matter or urgent concern. In this work, two technological platforms, namely, the use of a robust desulfurizing bacteria and the use of nanotechnology to decorate the surface of the bacteria with nanoparticles (NP), were combined to enhance biodesulfurization (BDS). BDS is an ecologically friendly method for desulfurizing petroleum products while avoiding damage to the hydrocarbons due to the high temperatures normally associated with physical desulfurization methods. First, a bacterium known to be a good organism for desulfurization (Rhodococcus erythropolis IGTS8) was employed in cell culture to remove a recalcitrant sulfur molecule from a common sulfur‐containing compound found in crude petroleum products (dibenzothiophene). 2‐Hydroxybiphenyl (2‐HBP) produced as a consequence of the BDS of dibenzothiophene was determined using Gibbs’ assay. The synthesized NP were characterized by field emission scanning electron microscope, transmission electron microscopy, Fourier transform infrared spectroscopy, X‐ray diffraction spectroscopy, and vibrating sample magnetometer. The field emission scanning electron microscope and transmission electron microscopy images showed the size of the NP is 7–8 nm. The decorated cells had a long lag phase, but the growth continued until 148 h (at OD600 = 3.408) while the noncoated bacteria grow until 96 h before entering the stationary phase at OD600 = 2.547. Gibbs’ assay results showed that production of 2‐HBP by decorated cells was 0.210 mM at t = 148 h, while 2‐HBP production by nondecorated cells was 0.182 mM at t = 96 h. Finally, the experiments were repeated in a fermenter.

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