Affinity and selectivity of plant proteins for red wine components relevant to color and aroma traits

The effects of fining with various plant proteins were assessed on Aglianico red wine, using both the young wine and wine aged for twelve and twenty-four months, and including wine unfined or fined with gelatin as controls. Color traits and fining efficiency were considered, along with the content of various types of phenolics and of aroma-related compounds of either varietal or fermentative origin. All agents had comparable fining efficiency, although with distinct kinetics, and had similar effects on wine color. Individual plant proteins and enzymatic hydrolyzates differed in their ability to interact with some anthocyanins, with specific proanthocyanidins complexes, and with some aroma components of fermentative origin. Changes in varietal aroma components upon fining were very limited or absent. Effects of all the fining agents tested in this study on the anthocyanidin components were most noticeable in young red wine, and decreased markedly with increasing wine ageing

TrustShadow: Secure Execution of Unmodified Applications with ARM TrustZone

The rapid evolution of Internet-of-Things (IoT) technologies has led to an emerging need to make it smarter. A variety of applications now run simultaneously on an ARM-based processor. For example, devices on the edge of the Internet are provided with higher horsepower to be entrusted with storing, processing and analyzing data collected from IoT devices. This significantly improves efficiency and reduces the amount of data that needs to be transported to the cloud for data processing, analysis and storage. However, commodity OSes are prone to compromise. Once they are exploited, attackers can access the data on these devices. Since the data stored and processed on the devices can be sensitive, left untackled, this is particularly disconcerting. In this paper, we propose a new system, TrustShadow that shields legacy applications from untrusted OSes. TrustShadow takes advantage of ARM TrustZone technology and partitions resources into the secure and normal worlds. In the secure world, TrustShadow constructs a trusted execution environment for security-critical applications. This trusted environment is maintained by a lightweight runtime system that coordinates the communication between applications and the ordinary OS running in the normal world. The runtime system does not provide system services itself. Rather, it forwards requests for system services to the ordinary OS, and verifies the correctness of the responses. To demonstrate the efficiency of this design, we prototyped TrustShadow on a real chip board with ARM TrustZone support, and evaluated its performance using both microbenchmarks and real-world applications. We showed TrustShadow introduces only negligible overhead to real-world applications.Comment: MobiSys 201

Studies on the mechanism of catalysis of iron-sulfur cluster transfer from IscU[2Fe2S] by HscA/HscB chaperones

The HscA/HscB chaperone/cochaperone system accelerates transfer of iron-sulfur clusters from the FeS-scaffold protein IscU (IscU(2)[2Fe2S], holo-IscU) to acceptor proteins in an ATP-dependent manner. We have employed visible region circular dichroism (CD) measurements to monitor chaperone-catalyzed cluster transfer from holo-IscU to apoferredoxin and to investigate chaperone-induced changes in properties of the IscU(2)[2Fe2S] cluster. HscA-mediated acceleration of [2Fe2S] cluster transfer exhibited an absolute requirement for both HscB and ATP. A mutant form of HscA lacking ATPase activity, HscA(T212V), was unable to accelerate cluster transfer, suggesting that ATP hydrolysis and conformational changes accompanying the ATP (T-state) to ADP (R-state) transition in the HscA chaperone are required for catalysis. Addition of HscA and HscB to IscU(2)[2Fe2S] did not affect the properties of the [2Fe2S] cluster, but subsequent addition of ATP was found to cause a transient change of the visible region CD spectrum, indicating distortion of the IscU-bound cluster. The dependence of the rate of decay of the observed CD change on ATP concentration and the lack of an effect of the HscA(T212V) mutant were consistent with conformational changes in the cluster coupled to ATP hydrolysis by HscA. Experiments carried out under conditions with limiting concentrations of HscA, HscB, and ATP further showed that formation of a 1:1:1 HscA-HscB-IscU(2)[2Fe2S] complex and a single ATP hydrolysis step are sufficient to elicit the full effect of the chaperones on the [2Fe2S] cluster. These results suggest that acceleration of iron-sulfur cluster transfer involves a structural change in the IscU(2)[2Fe2S] complex during the T --> R transition of HscA accompanying ATP hydrolysis

Structural modification of gluten proteins in strong and weak wheat dough as affected by mixing temperature

The effects of temperature ( 6525\ub0C) on dough rheological properties and gluten functionality have been investigated for decades, but no study has addressed the effect of low temperature (<30\ub0C) on gluten network attributes in flours with strong and weak dough characteristics. This study monitored changes in protein extractability in the presence and absence of reducing agents, the contents of readily accessible and SDS-accessible thiols, and the secondary structural features of proteins in doughs from commercial hard wheat flour (HWF) and soft wheat flour (SWF) mixed at 4, 15, and 30\ub0C. SWF mixed at 4 and 15\ub0C showed similar mixing properties as HWF mixed at 30\ub0C (which is the standard temperature). The effect of mixing temperature is different at the molecular level between the two flours studied. Protein features of HWF did not change as mixing temperature decreased, with the only exception being an increase in SDS-accessible thiols. Decreasing mixing temperature for SWF caused an increase in SDS protein solubility and SDS-accessible thiols as well as an increase in \u3b2-turn structures at the expense of \u3b2-sheet structures. Thus, noncovalent interactions appear to drive protein network at low temperatures (4 and 15\ub0C), whereas covalent interactions dominate at standard mixing temperature (30\ub0C) in doughs from both flours