Glycosylated peptides isolated from cheese whey have antifreezing activity.

The glycomacropeptide (GMP) present in the cheese whey byproduct can be an excellent antifreezing agent due to its unique molecular structure. The objective of this study was to concentrate this peptide and investigate its ice recrystallization inhibition (IRI) ability. Heat denaturation of the non-GMP proteins and preparative liquid chromatography were used to create fraction 1 (F1) and fraction 2 (F2) and these were tested using the splat assay and a modified sucrose sandwich assay to investigate their IRI activity.

Ice Recrystallization Inhibition Activity of Soy Protein Hydrolysates.

Identifying and developing ice recrystallization inhibitors from sustainable food proteins such as soy protein isolate (SPI) can lead to practical applications in both pharmaceutical and food industries. The objective of this study was to investigate the ice recrystallization inhibition (IRI) activity of SPI hydrolysates, and this was achieved by using an IRI activity-guided fractionation approach and relating IRI activity to interfacial molecular activity measured by vibrational sum frequency generation (VSFG). In addition, the impact of molecular weight (MW) and enzyme specificity was analyzed using three different proteases (Alcalase, trypsin, and pancreatin) and varying hydrolysis times.

Succinylation of zein and gelatin hydrolysates improved their ice recrystallization inhibition activity.

The goal of this research was to enhance the ice recrystallization inhibition (IRI) activity of zein and gelatin hydrolysates (ZH and GH, respectively) by succinylation modification. ZH was prepared by Alcalase treatment for 3 h and then modified by succinic anhydride (SA); whereas GH was made by Alcalase hydrolysis for 0.25 h and succinylated by n-octylsuccinic anhydride (OSA).

A novel automated protocol for ice crystal segmentation analysis using Cellpose and Fiji.

Accurate measurement of ice crystal size is an essential step in quantitative ice recrystallization inhibition (IRI) analysis using the sucrose sandwiching assay (SSA) and splat assay (SA). Here, we introduce a novel method of measuring ice crystal size and shape using Fiji and Cellpose, an anatomical segmentation algorithm, to address the time-consuming and limited number of ice particle determination associated with the mean largest grain size measurement. This new automated approach, displaying rapid segmentation of ∼70 s per image, measures every ice crystal in an image field of view, consequently reducing bias introduced by subjectively selecting the largest crystals in an image.

Deuterated polyunsaturated fatty acids inhibit photoirradiation-induced lipid peroxidation in lipid bilayers.

Lipid peroxidation (LPO) plays a key role in many age-related neurodegenerative conditions and other disorders. Light irradiation can initiate LPO through various mechanisms and is of importance in retinal and dermatological pathologies. The introduction of deuterated polyunsaturated fatty acids (D-PUFA) into membrane lipids is a promising approach for protection against LPO.

Threshold protective effect of deuterated polyunsaturated fatty acids on peroxidation of lipid bilayers.

Autoxidation of polyunsaturated fatty acids (PUFAs) damages lipid membranes and generates numerous toxic by-products implicated in neurodegeneration, aging, and other pathologies. Abstraction of bis-allylic hydrogen atoms is the rate-limiting step of PUFA autoxidation, which is inhibited by replacing bis-allylic hydrogens with deuterium atoms (D-PUFAs). In cells, the presence of a relatively small fraction of D-PUFAs among natural PUFAs is sufficient to effectively inhibit lipid peroxidation (LPO).

Deuterated Arachidonic Acids Library for Regulation of Inflammation and Controlled Synthesis of Eicosanoids: An In Vitro Study.

The synthesis of signal lipids, including eicosanoids, is not fully understood, although it is key to the modulation of various inflammatory states. Recently, isotopologues of essential polyunsaturated fatty acids (PUFAs) deuterated at bis-allylic positions (D-PUFAs) have been proposed as inhibitors of non-enzymatic lipid peroxidation (LPO) in various disease models. Arachidonic acid (AA, 20:4 n-6) is the main precursor to several classes of eicosanoids, which are produced by cyclooxygenases (COX) and lipoxygenases (LOX).

FINO initiates ferroptosis through GPX4 inactivation and iron oxidation.

Ferroptosis is a non-apoptotic form of regulated cell death caused by the failure of the glutathione-dependent lipid-peroxide-scavenging network. FINO is an endoperoxide-containing 1,2-dioxolane that can initiate ferroptosis selectively in engineered cancer cells. We investigated the mechanism and structural features necessary for ferroptosis initiation by FINO.

Isotope-reinforced polyunsaturated fatty acids protect mitochondria from oxidative stress.

Polyunsaturated fatty acid (PUFA) peroxidation is initiated by hydrogen atom abstraction at bis-allylic sites and sets in motion a chain reaction that generates multiple toxic products associated with numerous disorders. Replacement of bis-allylic hydrogens of PUFAs with deuterium atoms (D-PUFAs), termed site-specific isotope reinforcement, inhibits PUFA peroxidation and confers cell protection against oxidative stress. We demonstrate that structurally diverse deuterated PUFAs similarly protect against oxidative stress-induced injury in both yeast and mammalian (myoblast H9C2) cells.

Azide phosphoramidite in direct synthesis of azide-modified oligonucleotides.

Azide and phosphoramidite functions were found to be compatible within one molecule and stable for months in solution kept frozen at -20 °C. An azide-carrying phosphoramidite was used for direct introduction of multiple azide modifications into synthetic oligonucleotides. A series of azide-containing oligonucleotides were modified further using click reactions with alkynes.