Novel insights into construct toxicity, strain optimization, and primary sequence design for producing recombinant silk fibroin and elastin-like peptide in .

Spider silk proteins (spidroins) are a remarkable class of biomaterials that exhibit a unique combination of high-value attributes and can be processed into numerous morphologies for targeted applications in diverse fields. Recombinant production of spidroins represents the most promising route towards establishing the industrial production of the material, however, recombinant spider silk production suffers from fundamental difficulties that includes low titers, plasmid instability, and translational inefficiencies. In this work, we sought to gain a deeper understanding of upstream bottlenecks that exist in the field through the production of a panel of systematically varied spidroin sequences in multiple strains.

Genome-Wide Analysis of Translation in Replicatively Aged Yeast.

Protein synthesis is an essential process that affects major cellular functions including growth, energy production, cell signaling, and enzymatic reactions. However, how it is impacted by aging and how the translation of specific proteins is changed during the aging process remain understudied. Although yeast is a widely used model for studying eukaryotic aging, analysis of age-related translational changes using ribosome profiling in this organism has been challenging due to the need for isolating large quantities of old cells.

Inkjet-printed paper-based colorimetric sensor coupled with smartphone for determination of mercury (Hg).

We report an inkjet-printed paper based colorimetric sensor with silver nanoparticles (AgNPs) using smartphone and color detector App for on-site determination of mercuric ion (Hg) from environmental water samples. The AgNPs printed on Whatman filter paper (No. 1) is employed for detection of Hg which is reliant on the color change of NPs from yellow to discoloration depending on the concentration of target analyte in sample solution.

Distinct metabolic states of a cell guide alternate fates of mutational buffering through altered proteostasis.

Metabolic changes alter the cellular milieu; can this also change intracellular protein folding? Since proteostasis can modulate mutational buffering, if change in metabolism has the ability to change protein folding, arguably, it should also alter mutational buffering. Here we find that altered cellular metabolic states in E. coli buffer distinct mutations on model proteins.

Differential strengths of molecular determinants guide environment specific mutational fates.

Organisms maintain competitive fitness in the face of environmental challenges through molecular evolution. However, it remains largely unknown how different biophysical factors constrain molecular evolution in a given environment. Here, using deep mutational scanning, we quantified empirical fitness of >2000 single site mutants of the Gentamicin-resistant gene (GmR) in Escherichia coli, in a representative set of physical (non-native temperatures) and chemical (small molecule supplements) environments.

A G-quadruplex motif at the 3' end of sgRNAs improves CRISPR-Cas9 based genome editing efficiency.

Originating as a component of prokaryotic adaptive immunity, the type II CRISPR/Cas9 system has been repurposed for targeted genome editing in various organisms. Although Cas9 can bind and cleave DNA efficiently under in vitro conditions, its activity inside a cell can vary dramatically between targets owing to the differences between genomic loci and the availability of enough Cas9/sgRNA (single guide RNA) complex molecules for cleavage. Most methods have so far relied on Cas9 protein engineering or base modifications in the sgRNA sequence to improve CRISPR/Cas9 activity.

Selective inhibition of miR-21 by phage display screened peptide.

miRNAs are nodal regulators of gene expression and deregulation of miRNAs is causally associated with different diseases, including cancer. Modulation of miRNA expression is thus of therapeutic importance. Small molecules are currently being explored for their potential to downregulate miRNAs.

A simple and sensitive analytical method for the determination of antimony in environmental and biological samples.

The results of a study and application of leucocrystal violet for the determination of antimony in parts per million levels is described here. The proposed method is based on the reaction of antimony(III) with acidified potassium iodate to liberate iodine. The liberated iodine selectively oxidizes leucocrystal violet to crystal violet dye.