Aquaporin 0 (AQP0) is an integral membrane protein that facilitates water transport and cellular adhesion in the lens. Its dysfunction has been associated with cataractogenesis. Our earlier studies showed AQP0 undergoes aggregation when subjected to thermal stress and this aggregation seems to have been facilitated by mechanical agitation brought about by gentle stirring. The purpose of this study is to determine the secondary structural changes that precede aggregation and the role that α-crystallin plays in inhibiting those structural changes. Detergent solubilized calf lens AQP0 was subjected to thermal stress at 50°C for varying times. Secondary structural changes were measured by Circular Dichroism (CD) spectropolarimetry. Convex constraint analysis was used to deconvolute the CD spectra into pure component curves representing the secondary structural elements. Our results showed that under thermal stress, the α-helix content of AQP0 decreased from 50% to 7% with a concomitant increase from 0% to 52% in β-sheet content. The time-dependent loss of α-helical structure and gain of β-sheet structure appear to follow first-order kinetics with very similar values (∼30min) suggesting a single transition. In the presence of α-crystallin, this conversion to β-sheet is minimized, suggesting that the protein structure that binds to the molecular chaperone is mostly the α-helical structure of AQP0.
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http://dx.doi.org/10.1016/j.bbrc.2014.07.056 | DOI Listing |
Bot Stud
January 2025
Crop Science Division, Taiwan Agricultural Research Institute, Ministry of Agriculture, Taichung, 413, Taiwan.
Background: Rice is a staple food for the global population. However, extreme weather events threaten the stability of the water supply for agriculture, posing a critical challenge to the stability of the food supply. The use of technology to assess the water status of rice plants enables the precise management of agricultural water resources.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
School of Food Science and Technology, Shihezi University, Shihezi, Xinjiang 832003, China; Key Laboratory of Characteristics Agricultural Product Processing and Quality Control (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Shihezi University, Shihezi, Xinjiang 832000, China; Key Laboratory for Food Nutrition and Safety Control of Xinjiang Production and Construction Corps, Shihezi University, Shihezi, Xinjiang 832000, China. Electronic address:
The limited solubility, rapid metabolism, and poor bioavailability of curcumin restrict its application. In this study, we synthesized chickpea protein isolate (CPI)-citrus pectin (CP) conjugates to prepare an emulsion delivery system that enhances the stability and bioavailability of curcumin. The CPI-CP emulsion achieved a curcumin encapsulation efficiency of 86.
View Article and Find Full Text PDFComp Biochem Physiol A Mol Integr Physiol
January 2025
Biosciences, College of Life & Environmental Sciences, University of Exeter, UK; Centre for Sustainable Aquaculture Futures, University of Exeter, Exeter, UK.
Fish are ectothermic animals with temperature playing a key role in their health, growth and survival. Greater occurrence of heat waves and temperature extremes, as a result of global climate change, has the potential to impact both wild and farmed populations. Within aquaculture, production is threatened by a multitude of stressors, including adverse temperatures.
View Article and Find Full Text PDFPolymers (Basel)
January 2025
Department of Physics, Washington State University, Pullman, WA 99163, USA.
This work aims to determine the mechanism of the photomechanical response of poly(Methyl methacrylate) polymer doped with the photo-isomerizable dye Disperse Red 1 using the non-isomerizable dye Disperse Orange 11 as a control to isolate photoisomerization. Samples are free-standing thin films with thickness that is small compared with the optical skin depth to assure uniform illumination and photomechanical response throughout their volume, which differentiates these studies from most others. Polarization-dependent measurements of the photomechanical stress response are used to deconvolute the contributions of angular hole burning, molecular reorientation and photothermal heating.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
School of Metallurgy, Northeastern University, Shenyang 110819, China.
The constitutive model was commonly used to describe the flow stress of materials under specific strain, strain rate, and temperature conditions. In order to study the thermal-mechanical behavior of DH460 continuous casting steel during the solidification end heavy reduction (HR) process accurately. The high-temperature compression experiment was carried out, and phenomenological constitutive models were established based on the experimental results.
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