Effect of Betaine and Arginine on Interaction of αB-Crystallin with Glycogen Phosphorylase b

Protein–protein interactions (PPIs) play an important role in many biological processes in a living cell. Among them chaperone–client interactions are the most important. In this work PPIs of αB-crystallin and glycogen phosphorylase b (Phb) in the presence of betaine (Bet) and arginine (Arg) at 48 °C and ionic strength of 0.15 M were studied using methods of dynamic light scattering, differential scanning calorimetry, and analytical ultracentrifugation. It was shown that Bet enhanced, while Arg reduced both the stability of αB-crystallin and its adsorption capacity (AC₀) to the target protein at the stage of aggregate growth. Thus, the anti-aggregation activity of αB-crystallin increased in the presence of Bet and decreased under the influence of Arg, which resulted in inhibition or acceleration of Phb aggregation, respectively. Our data show that chemical chaperones can influence the tertiary and quaternary structure of both the target protein and the protein chaperone. The presence of the substrate protein also affects the quaternary structure of αB-crystallin, causing its disassembly. This is inextricably linked to the anti-aggregation activity of αB-crystallin, which in turn affects its PPI with the target protein. Thus, our studies contribute to understanding the mechanism of interaction between chaperones and proteins.     

Difluoromethylornithine (DFMO), an Inhibitor of Polyamine Biosynthesis,and Antioxidant N-Acetylcysteine Potentiate Immune Response in Mice to the Recombinant Hepatitis C Virus NS5B Protein

Hepatitis C virus (HCV) is one of the main triggers of chronic liver disease. Despite tremendous progress in the HCV field, there is still no vaccine against this virus. Potential vaccines can be based on its recombinant proteins. To increase the humoral and, especially, cellular immune response to them, more effective adjuvants are needed. Here, we evaluated a panel of compounds as potential adjuvants using the HCV NS5B protein as an immunogen. These compounds included inhibitors of polyamine biosynthesis and urea cycle, the mTOR pathway, antioxidants, and cellular receptors. A pronounced stimulation of cell proliferation and interferon-γ (IFN-γ) secretion in response to concanavalin A was shown for antioxidant N-acetylcysteine (NAC), polyamine biosynthesis inhibitor 2-difluoromethylornithine (DFMO), and TLR9 agonist CpG ODN 1826 (CpG). Their usage during the immunization of mice with the recombinant NS5B protein significantly increased antibody titers, enhanced lymphocyte proliferation and IFN-γ production. NAC and CpG decreased relative Treg numbers; CpG increased the number of myeloid-derived suppressor cells (MDSCs), whereas neither NAC nor DFMO affected MDSC counts. NAC and DFMO suppressed NO and interleukin 10 (IL-10) production by splenocytes, while DFMO increased the levels of IL-12. This is the first evidence of immunomodulatory activity of NAC and DFMO during prophylactic immunization against infectious diseases.     

Artificial Light Regulation of an Allosteric Bienzyme Complex by a Photosensitive Ligand

The artificial regulation of proteins by light is an emerging subdiscipline of synthetic biology. Here, we used this concept to photocontrol both catalysis and allostery within the heterodimeric enzyme complex imidazole glycerol phosphate synthase (ImGP‐S). ImGP‐S consists of the cyclase subunit HisF and the glutaminase subunit HisH, which is allosterically stimulated by substrate binding to HisF. We show that a light‐sensitive diarylethene (1,2‐dithienylethene, DTE)‐based competitive inhibitor in its ring‐open state binds with low micromolar affinity to the cyclase subunit and displaces its substrate from the active site. As a consequence, catalysis by HisF and allosteric stimulation of HisH are impaired. Following UV‐light irradiation, the DTE ligand adopts its ring‐closed state and loses affinity for HisF, restoring activity and allostery. Our approach allows for the switching of ImGP‐S activity and allostery during catalysis and appears to be generally applicable for the light regulation of other multienzyme complexes.     

Increased use of district heating in industrial processes – Impacts on heat load duration

Current knowledge of the potential for an increased use of industrial district heating (DH) due to conversions of industrial processes to DH is limited. In this paper, a Method for Heat Load Analysis (MeHLA) for exploring industrial DH conversions has been developed. This method can be a helpful tool for analyzing the impact different industrial processes have on the local DH system, when processes that utilize electricity and other fuels, convert to utilizing DH. Heat loads for different types of industries and processes are analyzed according to characteristics such as temperature levels and time-dependency. MeHLA has been used to analyze 34 Swedish industries and the method demonstrates how conversion of industrial processes to DH can result in heat load duration curves that are less outdoor temperature-dependent and more evenly distributed over the year. An evenly distributed heat load curve can result in increased annual operating time for base load DH plants such as cogeneration plants, leading to increased electricity generation. In addition to the positive effects for the DH load duration curve, the conversions to DH can also lead to an 11% reduction in the use of electricity, a 40% reduction in the use of fossil fuels and a total energy end-use saving of 6% in the studied industries. Converting the industrial processes to DH will also lead to a potential reduction of the global carbon dioxide emissions by 112,000 tonnes per year.     

To what does perceived criticism refer? Constructive, destructive, and general criticism.

General spousal perceived criticism (PC) robustly predicts psychological symptoms and is associated with marital discord (e.g., Hooley & Teasdale, 1989); however, it is unclear what types of criticism PC encompasses (Renshaw, 2008). One hundred eighteen couples rated general PC and both constructive and destructive criticism from their own videotaped spousal discussions. Independent judges also coded criticism from the discussions. Results suggest that destructive rather than constructive criticism is related to PC. That PC primarily reflects destructive criticism may explain its utility in predicting relapse. Future studies will benefit from separate application of constructive and destructive criticism measures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

SenToy in FantasyA: Designing an Affective Sympathetic Interface to a Computer Game

We describe the design process of an affective control toy, named SenToy, used to control a synthetic character in a computer game. SenToy allows players to influence the emotions of a synthetic character placed in FantasyA, a 3D virtual game. By expressing gestures associated with anger, fear, surprise, sadness and joy through SenToy, players influence the emotions of the character they control in the game. When designing SenToy we hypothesized that players would manipulate the toy to express emotions using a particular set of gestures. Those gestures were drawn from literature on how we express emotions through bodily movements and from emotion theories. To evaluate our idea we performed a Wizard Of Oz study [1]. The results of the study show that there are behaviours that players easily pick up for expressing emotions through the gestures with the toy, though not necessarily the ones extracted from literature. The study also provided some indication on what type of toy we should build, in particular, its ‘look and feel’. Correspondence to: Ms A. Paiva, IST & Instituto de Engenharia de Sistemas e Computadores, Rua Alves Redol 9, 1000 Lisboa, Portugal. Email: Ana.Paiva@inesc.pt     

Automated Verification of Completeness and Consistency of Abstract State Machine Specifications using a SAT Solver

In the requirements engineering community, consistency and completeness have been identified as important properties of system specifications. Custom algorithms to verify these properties automatically have been devised for a number of specification languages, including SCR, RSML, and Statecharts. In this paper, we provide means to automatically verify completeness and consistency of Abstract State Machine (ASM) specifications. The verification is performed using a widely available tool, a SAT solver. The use of a SAT solver removes the need for designing and fine tuning language specific verification algorithms. Furthermore, the use of a SAT solver automates the verification procedure and produces a counterexample automatically when a specification is incomplete or inconsistent. We provide an algorithm to translate ASM specifications to a SAT problem instance. The translation is illustrated using the TASM toolset in conjunction with the “production cell system” case study.     

Variability between domestic buildings: the impact on energy use

Variations in operational use (in the time domain) and in design and use (between buildings) are critical for district systems. The effects on energy use of behavioural (stochastic profiles of occupancy and end uses) and physical variations (size, orientation, insulation and air tightness) amongst many buildings is examined. Rather than investigating just the variability of these factors, the aim is to identify subsequent impacts on building energy use. To achieve this, dynamic building energy simulations in EnergyPlus are performed. Results include total demands and their distributions, and temporal and probabilistic profiles. Very large variations in total heating demand are noted. Temporal profiles show changes in peak loads, load durations and periods of zero load. Probabilistic profiles and cumulative distributions show that a few buildings are responsible for the majority of total loads. Full detailed simulations are identified as critical when assessing temporal effects such as peak loads and storage sizing.