Polar group exchange receptor-ligand engineering of protein kinase B's pleckstrin homology domain

A diverse range of cellular functions are influenced by the activity of protein kinase B (PKB, also known as Akt). PKB is involved in a number of physiological pathways, perturbation of which can lead to pathological conditions. PKB activation has been shown to involve binding of its pleckstrin homology (PH) domain to PtdIns(3,4)P2 and PtdIns(3,4,5)P3 generated on the inner face of the plasma membrane upon receipt of an external hormonal signal. To study PKB independently of other inositol-phospholipid binding proteins which recognise the same lipid signals, their mutual dependence on the same ligand must be broken. It is proposed that this can be achieved by mutating PKB‟s PtdInsPn binding PH domain to accept an unnatural ligand. By altering the inositol-phospholipid head-group to include an additional carboxylic acid substituent, its binding to the wild-type PH domains should be inhibited through steric compression. Disruption of a salt-bridge in the wall of the binding pocket by point mutation of glutamate 17 to alanine, E17A, introduces an additional positively charged pocket into the PH domain of PKB, which should bind with the tailored lipid, resulting in a polar group exchange receptor-ligand pair. To this end, a novel 2-O-acetic acid functionalised analogue of Ins(1,3,4,5)P4 was synthesised. The key steps were the protection/deprotection of myo-inositol‟s hydroxyls, enabling selective functionalisation of the 2-hydroxyl, and phosphorylation of the 1,3,4,5-O positions. Using an allyl ether as a masked form of acetic acid allowed a divergent synthetic strategy to be employed to access additional 2-O analogues. Both the wild-type and the E17A mutant of the PH domain were expressed in order to assess ligand binding, and determine whether an ion pair exchange receptor-ligand interaction occurred. Intrinsic tryptophan fluorescence spectrometry was initially used, but was unsuccessful due to denaturing problems arising from isolating the protein. Isothermal titration calorimetry suggested binding, but protein concentration could not be increased high enough for the binding energy to become significantly greater than the energy of mixing. The analogues were also tested as potential inositol poly-phosphate phosphatase catalytic (IPPc) domain inhibitors

Product longevity and shared ownership: Sustainable routes to satisfying the world’s growing demand for goods 

It has been estimated that by 2030 the number of people who are wealthy enough to be significant consumers will have tripled. This will have a dramatic impact on the demands for primary materials and energy. It has been estimated that with improvements in design and manufacturing it is possible to maintain the current level of production using 70% of the current primary material consumed. Even with these improvements on the production side, there will still be a doubling of primary material requirements by the end of the century, with accompanying rises in industrial energy demand, if the rise in demand for goods and services is to be met. It is therefore clear that the consumption of products must also be explored. Product longevity and using goods more intensively are two strategies which could reduce the demand for new goods. If products last longer, then manufacturing output can concentrate on emerging markets rather than the market for replacement goods. There are many goods which are infrequently used, these seldom wear out. The total demand for such could be drastically reduced if they we re shared with other people. Sharing of goods has traditionally been conducted between friends or by hiring equipment, but modern communication systems and social media could increase the opportunities to share goods. Sharing goods also increases access to a range of goods for those on low incomes. From a series of workshops it has been found that the principal challenges are sociological rather than technological. This paper contains a discussion of these challenges and explores possible futures where these two strategies have been adopted. In addition, the barriers and opportunities that these strategies offer for 548 AIMS Energy Volume 3, Issue 4, 547-561. consumers and businesses are identified, and areas where government policy could be instigated to bring about change are highlighted

Prenatal development is linked to bronchial reactivity: epidemiological and animal model evidence

Chronic cardiorespiratory disease is associated with low birthweight suggesting the importance of the developmental environment. Prenatal factors affecting fetal growth are believed important, but the underlying mechanisms are unknown. The influence of developmental programming on bronchial hyperreactivity is investigated in an animal model and evidence for comparable associations is sought in humans. Pregnant Wistar rats were fed either control or protein-restricted diets throughout pregnancy. Bronchoconstrictor responses were recorded from offspring bronchial segments. Morphometric analysis of paraffin-embedded lung sections was conducted. In a human mother-child cohort ultrasound measurements of fetal growth were related to bronchial hyperreactivity, measured at age six years using methacholine. Protein-restricted rats' offspring demonstrated greater bronchoconstriction than controls. Airway structure was not altered. Children with lesser abdominal circumference growth during 11-19 weeks' gestation had greater bronchial hyperreactivity than those with more rapid abdominal growth. Imbalanced maternal nutrition during pregnancy results in offspring bronchial hyperreactivity. Prenatal environmental influences might play a comparable role in humans

Games based learning for Exploring Cultural Conflict

In this paper we discuss the early stage design of MIXER, a technology enhance educational application focused at supporting children in learning about cultural conflict, achieved through the use of a game with an effective embodied AI agent. MIXER is being developed re-using existing technology applied to a different context and purpose with the aim of creating an educational and enjoyable experience for 9-11 year olds. This paper outlines MIXER’s underpinning technology and theory. It presents early stage design and development, highlighting current research directions

Impact on energy requirements and emissions of heat pumps and micro-cogenerators participating in demand side management

Belgium Herbarium image of Meise Botanic Garden