Comparative Proteomics Provides Insights into Metabolic Responses in Rat Liver to Isolated Soy and Meat Proteins.

It has been reported that isolated dietary soy and meat proteins have distinct effects on physiology and liver gene expression, but the impact on protein expression responses are unknown. Because these may differ from gene expression responses, we investigated dietary protein-induced changes in liver proteome. Rats were fed for 1 week semisynthetic diets that differed only regarding protein source; casein (reference) was fully replaced by isolated soy, chicken, fish, or pork protein. Changes in liver proteome were measured by iTRAQ labeling and LC-ESI-MS/MS. A robust set totaling 1437 unique proteins was identified and subjected to differential protein analysis and biological interpretation. Compared with casein, all other protein sources reduced the abundance of proteins involved in fatty acid metabolism and Pparα signaling pathway. All dietary proteins, except chicken, increased oxidoreductive transformation reactions but reduced energy and essential amino acid metabolic pathways. Only soy protein increased the metabolism of sulfur-containing and nonessential amino acids. Soy and fish proteins increased translation and mRNA processing, whereas only chicken protein increased TCA cycle but reduced immune responses. These findings were partially in line with previously reported transcriptome results. This study further shows the distinct effects of soy and meat proteins on liver metabolism in rats.

Delivery of hyperoside by using a soybean protein isolated-soy soluble polysaccharide nanocomplex: Fabrication, characterization, and in vitro release properties.

Nanoparticles made from natural proteins and polysaccharides are green, biodegradable, and sustainable. In this study, soybean protein isolate (SPI) and soybean soluble polysaccharide (SSPS) were employed as delivery vehicles for hyperoside (HYP) to explore the mechanism of the formation of complexes and evaluate the performance of this mechanism at different pH values. The structures of SPI-SSPS-HYP complexes were studied by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and atomic force microscopy (AFM), and the stability was evaluated based on free radical scavenging ability, loading rate, and simulated release. The results showed that nanoparticles were subjected to non-covalent electrostatic complexation, which was affected mainly by electrostatic, hydrogen bond, and hydrophobic interactions, and the optimal encapsulation efficiency was 85.56% at pH 3.5. Encapsulated HYP retained its high antioxidant capacity. This study provides a new strategy for developing a biodegradable nanocarrier with superior encapsulation properties, enhancing the application range of HYP.

Effects of irradiation treatment on protein structure and digestion characteristics of seed-watermelon (Citrullus lanatus var.) kernel protein.

This study examined the effects of different doses of irradiation treatments on protein structure and digestion characteristic of seed-watermelon seed kernel protein. The results showed that, the molecular structure of seed-watermelon kernel protein was unfolded after the irradiation treatment, the content of ß-sheet structure in the secondary structure was decreased, while the content of random coil structure increased. The average particle size of the protein increased, and the hydrophobic group buried in the ß-sheet structure was exposed hence the surface hydrophobicity increased. Besides, the surface morphology of seed-watermelon protein changed from smooth and flat to coarse and concave, the specific surface area in contact with the aqueous medium increased and its solubility increased, the distribution of peptides in the digesta became wider, and the small molecular weight peptides gradually increased.

Molecular changes of phenolic-protein interactions in isolated proteins from flaxseed and soybean using Native-PAGE, SDS-PAGE, RP-HPLC, and ESI-MS analysis.

The effects of protein-phenolic interactions on the molecular characteristics of soybean and flaxseed proteins were investigated. Proteins were isolated from soybean and flaxseed using isoelectric precipitation, followed by extraction of free and bound phenolics. The effects of elimination of the phenolic compounds on molecular characteristics of the protein isolates were studied using reversed phase-high performance liquid chromatography (RP-HPLC), Native and sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis (PAGE) and electron spray ionization-mass spectrometry (ESI-MS). The Native-PAGE fractions from isolated proteins from full-fat flaxseed and soybean revealed that protein migration was affected by removal of bound phenolics. SDS-PAGE from full-fat and defatted protein isolates of flaxseed and soybean revealed that the removal of bound phenolics affected the molecular characteristics of protein subunits. Soybean protein isolates had protein-phenolic interactions through acidic and basic subunits. RP-HPLC and ESI-MS showed that the removal of bound and free phenolics had only minor effects on the molecular characteristics of isolated proteins from defatted and full-fat soybean. With respect to isolated proteins from flaxseed, the removal of bound phenolics showed little effect on the electrophoretic behavior of the proteins or the protein subunits. PRACTICAL APPLICATIONS: Phenolic-protein and phenolic-lipid-protein interactions may affect the nutritional, physicochemical, and functional properties of isolated proteins from food in flaxseed and soybean.

COMPARATIVE STUDIES ON THE SUB-UNIT COMPOSITION OF THE ALBUMINS, VICILINS AND LEGUMINS OF ISOLATED PROTEIN BODIES FROM COTYLEDONS OF DRY SEEDS OF TWO MEMBERS OF THE LEGUMINOSAE: CYTISUS SCOPARIUS (L.) LINK AND C. SCOPARIUS SSP. MARITIMUS (ROUY) HEYWOOD.

The isolated protein bodies of Cytisus scoparius (L.) Link and Cytisus scoparius ssp. maritimus (Rouy) Heywood were observed by scanning electron microscopy; they showed comparable shapes and sizes. The protein content and the sub-unit composition of the fractionated albumins, vicilins and legumins, however, showed significant electrophoretic differences between the two plants, both at the qualitative and quantitative levels.

Isolated protein S deficiency presenting as catastrophic systemic arterial and subsequently venous thrombosis.

Isolated protein S deficiency is an inherited condition having proven association with venous thromboembolism. There is controversy regarding clear association between protein S deficiency and arterial thrombosis. It is therefore necessary to bring focus to this uncommon clinical condition and highlight the probable association with arterial thrombosis facilitating timely diagnosis of this condition. We describe a 48-year-old male with stroke and pulmonary thromboembolism with chronic deep vein thrombosis secondary to isolated protein S deficiency, managed with thrombolysis and long-term anticoagulation.