Microfluidic integrated capacitive biosensor for C-Reactive Protein label-free and real-time detection

Microfluidic chip has been integrated with capacitive biosensor based on mass-producible three-dimensional (3D) interdigital electrode arrays. To achieve the monitoring of biosensor preparation and the cardiac and periodontitis-related biomarkers, all...

Local dynamics of the photo-switchable protein PYP in ground and signalling state probed by 2D-IR spectroscopy of –SCN labels

We employ 2D-IR spectroscopy of the protein label –SCN to describe the local dynamics in the photo-switchable protein PYP in its dark state (pG) and after photoactivation, concomitant with vast structural rearrangements, in its signalling state (pB).

A new perspective on membrane-embedded Bax oligomers using DEER and bioresistant orthogonal spin labels

Bax is a Bcl-2 protein crucial for apoptosis initiation and execution, whose active conformation is only partially understood. Dipolar EPR spectroscopy has proven to be a valuable tool to determine coarse-grained models of membrane-embedded Bcl-2 proteins. Here we show how the combination of spectroscopically distinguishable nitroxide and gadolinium spin labels and Double Electron-Electron Resonance can help to gain new insights into the quaternary structure of active, membrane-embedded Bax oligomers. We show that attaching labels bulkier than the conventional MTSL may affect Bax fold and activity, depending on the protein/label combination. However, we identified a suitable pair of spectroscopically distinguishable labels, which allows to study complex distance networks in the oligomers that could not be disentangled before. Additionally, we compared the stability of the different spin-labeled protein variants in E. coli and HeLa cell extracts. We found that the gem-diethyl nitroxide-labeled Bax variants were reasonably stable in HeLa cell extracts. However, when transferred into human cells, Bax was found to be mislocalized, thus preventing its characterization in a physiological environment. The successful use of spectroscopically distinguishable labels on membrane-embedded Bax-oligomers opens an exciting new path towards structure determination of membrane-embedded homo- or hetero-oligomeric Bcl-2 proteins via EPR.

Characterization and Comparative Analysis of Foods with Front-of-Package Protein Claims (P04-149-19)

Objectives The objective of this study is to characterize food products that make front-of-package protein claims. The study will also determine how these protein-labeled products compare nutritionally to similar products without protein claims. Methods Products with front-of-package protein claims were analyzed using Label Insight, an online product database of label information and product images for over 330,000 foods. Product categories with the greatest proportion of products with protein claims were determined. An assessment of which type of protein claim (e.g., “Good Source of Protein,” “5 g of protein per serving”) is present most frequently was performed. Logistic regression was used to predict the types of claims that are made based on the type of product (e.g., yogurt, cereal). Additionally, within those product categories that contain a high proportion of protein-labeled products, a cross-sectional comparison of the calorie, protein, fat, sugar, and sodium content of food products with and without front-of-package protein labels was completed. Results Preliminary data reveal that the three food categories with the greatest proportion of protein claims relative to all products in that category are: Dairy, Frozen Food, and Cereal & Breakfast Foods. These categories are comprised of 15.33%, 14.32%, and 13.83% of products with protein claims, respectively. Preliminary results for the nutritional comparisons of cereal using Mann-Whitney U tests revealed that median protein per 100 g and median total fat per 100 g were both statistically significantly higher in the cereals with protein labels than in the cereal without protein labels, (U = 79, 616.5, P < .001 and U = 31,186.5, P < .001, respectively). Conclusions Our preliminary findings indicate that foods making protein claims are common in multiple product categories and that some nutrients may be higher in those that have a protein label. Ongoing quantitative analyses are further evaluating the extent of these nutritional differences. Funding Sources N/A.

Analysis of Ultrafast Transient Absorption Spectroscopy Data using Integrative Data Analysis Platform: 1. Data Processing, Fitting, and Model Selection

ABSTRACTThis manuscript describes a workflow for analysis of transient absorption (TA) spectroscopy data using Integrative Data Analysis Platforms (IDAP) software package. Time-dependent spectral series are analyzed through evaluation of the isosbestic point and kinetics of excited state and ground-state bleach decays. Model fitting and selection based on Akaike’s Information Criterion is discussed. As a practical example, we analyze excitation decays of a common protein label, Alexa Fluor 647.