Heterologous production of brazzein is complicated by the fact that the protein contains four disulfide bridges and requires a specific N-terminal sequence. Our previous protocol for producing the protein from Escherichia coli involved several steps with low overall yield: expression as a fusion protein, denaturation and renaturation, oxidation of the cysteines, and cleavage by cyanogen bromide at an engineered methionine adjacent to the desired N-terminus. The new protocol described here, which is much faster and leads to a higher yield
of native protein, involves the production of brazzein in E coli as a fusion with SUMO. The isolated protein product contains the brazzein domain folded with CHIR98014 chemical structure correct disulfide bonds formed and is then cleaved
with a specific SUMO protease to liberate native brazzein. This protocol represents an important advancement that will enable more efficient research into the interaction between brazzein and the receptor as well as investigations to test the potential of brazzein as a commercially viable natural low calorie sweetener. (C) 2007 Elsevier Inc. All rights reserved.”
“The process of gene expression has material costs caused by the quantities of carbon, nitrogen, sulfur and phosphorus that are needed to make mRNAs and proteins. When any such chemical element is ecologically limiting, mutations increasing these costs can reduce growth. Here, we ask if such mutations are ‘visible’ to natural selection in the yeast Saccharomyces cerevisiae. We find that mutations Acyl CoA dehydrogenase causing JAK inhibitor small increases in expression and even single amino acid replacements can be subject
to natural selection on the basis of their material costs.”
“This study relates two behaviours, each well documented within its own literature but not previously considered together: closing-in behaviour (CIB) and the effect of visual distractors on reaching. CIB is common in typically developing children, and in adults with dementia, and classically manifests as the tendency to perform graphic copying tasks very close to, or on the top of the model. The effect of visual distractors on reaching has been studied extensively in normal adults. Distractors induce characteristic deviations of the reach, usually away from the distractor, which imply that a competing response towards the distractor is automatically primed, and actively suppressed. It is possible that CIB reflects a failure to inhibit motor distraction, such that the acting hand is attracted automatically to a salient stimulus (the model, during copying tasks). This hypothesis predicts that CIB should be associated with distractor effects during reaching, characterised by veering towards, rather than away from the distractor.