Biogenic synthesis of gold nanoparticles using Sargassum tenerrimum and its evaluation of antibacterial activity against Escherichia coli and Salmonella typhi

1291-1297An important aspect of nanotechnology is the development of a reliable and ecofriendly method for the synthesis of nanomaterials. In the present study, Sargassum tenerrimum extract was used to synthesize gold nanoparticles (AuNPs) by the reduction of AuCl4− ions to Au0. The formation and morphology of the synthesized AuNPs were investigated using \UV–visible spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, X-ray diffraction, and field emission scanning electron microscopy with energy dispersive X-ray analysis. The nanoparticles synthesized at 60 °C were spherical in shape while few were also hexagonal in shape with the size ranging between 10 and 40 nm. The antibacterial activity of AuNPs was tested against Escherichia coli (ATCC 25922) and Salmonella typhi (ATCC 6539). On examination under an epifluorescence microscope, it was found to cause a significant amount of deterioration to the bacterial cells

In-Silico Computing of the Most Deleterious nsSNPs in HBA1 Gene.

BACKGROUND:α-Thalassemia (α-thal) is a genetic disorder caused by the substitution of single amino acid or large deletions in the HBA1 and/or HBA2 genes. METHOD:Using modern bioinformatics tools as a systematic in-silico approach to predict the deleterious SNPs in the HBA1 gene and its significant pathogenic impact on the functions and structure of HBA1 protein was predicted. RESULTS AND DISCUSSION:A total of 389 SNPs in HBA1 were retrieved from dbSNP database, which includes: 201 non-coding synonymous (nsSNPs), 43 human active SNPs, 16 intronic SNPs, 11 mRNA 3' UTR SNPs, 9 coding synonymous SNPs, 9 5' UTR SNPs and other types. Structural homology-based method (PolyPhen) and sequence homology-based tool (SIFT), SNPs&Go, PROVEAN and PANTHER revealed that 2.4% of the nsSNPs are pathogenic. CONCLUSIONS:A total of 5 nsSNPs (G60V, K17M, K17T, L92F and W15R) were predicted to be responsible for the structural and functional modifications of HBA1 protein. It is evident from the deep comprehensive in-silico analysis that, two nsSNPs such as G60V and W15R in HBA1 are highly deleterious. These "2 pathogenic nsSNPs" can be considered for wet-lab confirmatory analysis

Graphic illustration of bioinformatic tools used for the precise identification of the most deleterious nsSNPs of <i>HBA1</i> gene.

<p>Graphic illustration of bioinformatic tools used for the precise identification of the most deleterious nsSNPs of <i>HBA1</i> gene.</p

Cumulative prediction of possible deleterious nsSNPs.

<p>Cumulative prediction of possible deleterious nsSNPs.</p

Total energy and RMSD of deleterious nsSNPs.

<p>Total energy and RMSD of deleterious nsSNPs.</p

Molecular dynamic simulation of native and mutant HBA1.

<p>Molecular dynamic simulation of native and mutant HBA1.</p

Super imposed 3D structures of the native and highly deleterious mutated HBA1 proteins.

<p>Super imposed 3D structures of the native and highly deleterious mutated HBA1 proteins.</p

Prediction matching to the highly pathogenic nsSNPs of <i>HBA1</i> gene.

<p>The 2 highly pathogenic nsSNPs are having the scores: Polyphen >0.9; Panther >0.55; SNPs&Go >0.8; SIFT = 0; PROVEAN < -8; mCSM < -0.1; SNAP2 >65.</p

Comparing the helix, protein binding, Disordered region and exposed/buried residues.

<p>Comparing the helix, protein binding, Disordered region and exposed/buried residues.</p