Shellfish Tropomyosin IgE Cross-Reactivity Differs Among Edible Insect Species.

Scope: Insects are a potentially environmentally friendly alternative dietary protein source to supplement mammalian and fish sources, but potential allergenic risks are a concern. Consumption of insects may result in anaphylaxis and has been implicated in cross-reactivity with shellfish. Many allergenic proteins may be involved in cross-reactivity, including tropomyosin (TM).

Effects of high-pressure processing and enzymatic dephosphorylation on phosvitin properties.

Background: Egg phosvitin could be a good source of functional peptides. Enzymatic dephosphorylation and high-pressure processing combined with thermal treatment applied before proteolysis could produce phosvitin hydrolysates with different properties compared to its native form.

Results: Phosvitin structure was maintained overall during high-pressure treatment of 600 MPa applied at an initial temperature of 65 °C regardless of the pH and duration of treatment, confirming the high structural stability of this phosphoprotein.

P39, a novel soybean protein allergen, belongs to a plant-specific protein family and is present in protein storage vacuoles.

Soybean lecithins are seeing increasing use in industry as an emulsifier and food additive. They are also a growing source of human food allergies, which arise principally from the proteins fractionating with the lecithin fraction during manufacture. A previous study (Gu, X.

Microarray profiling of skeletal muscle sarcoplasmic reticulum proteins.

Microarrays were developed to profile the level of proteins associated with calcium regulation in sarcoplasmic reticulum (SR) isolated from porcine Longissimus muscle. The microarrays consisted of SR preparations printed onto to glass slides and probed with monoclonal antibodies to 7 target proteins. Proteins investigated included: ryanodine receptor, (RyR), dihydropyridine receptor, (DHPR), triadin (TRI), calsequestrin (CSQ), 90 kDa junctional protein (JSR90), and fast-twitch and slow-twitch SR calcium ATPases (SERCA1 and SERCA2).

C-Terminal 23 kDa polypeptide of soybean Gly m Bd 28 K is a potential allergen.

Gly m Bd 28 K is a major soybean (Glycine max Merr.) glycoprotein allergen. It was originally identified as a 28 kDa polypeptide in soybean seed flour.

Stability of the allergenic soybean Kunitz trypsin inhibitor.

The soybean Kunitz trypsin inhibitor (SKTI) is a 21.5 kDa allergenic protein that belongs to the family of all antiparallel beta-sheet proteins that are highly resistant to thermal and chemical denaturation. Spectroscopic and biochemical techniques such as circular dichroism (CD), ANS fluorescence and proteolysis were used to study its molecular structure under denaturing conditions such as acid and heat to which these allergens are commonly exposed during food processing.

Reversible denaturation of the soybean Kunitz trypsin inhibitor.

The soybean Kunitz trypsin inhibitor (SKTI) is a beta-sheet protein with unusual stability to chemical and thermal denaturation. Different spectroscopic criteria were used to follow the thermal denaturation and renaturation of SKTI. Upon heating to 70 degrees C, changes in UV difference spectra showed increased absorbance at 292 and 297 nm, attributable to perturbation of aromatic residues.

Identification and analysis of a conserved immunoglobulin E-binding epitope in soybean G1a and G2a and peanut Ara h 3 glycinins.

To identify conserved immunoglobulin E (IgE)-binding epitopes among legume glycinins, we utilized recombinant soybean G2a and G2a-derived polypeptide fragments. All of these fusion polypeptides bound IgE, and the C-terminal 94-residue fragment appeared to bind more IgE. Using synthetic peptides we identified S219-N233 (S(219)GFAPEFLKEAFGVN(233)) as the dominant IgE-binding epitope.

Identification of IgE-binding proteins in soy lecithin.

Background: Soy lecithin is widely used as an emulsifier in processed foods, pharmaceuticals and cosmetics. Soy lecithin is composed principally of phospholipids; however, it has also been shown to contain IgE-binding proteins, albeit at a low level. A few clinical cases involving allergic reactions to soy lecithin have been reported.

Capillary electrophoretic analysis of mu- and m-calpain using fluorescently labeled casein substrates.

Calpains are unique calcium-dependent thiol proteases that have been proposed to participate in a number of physiological processes including signal transduction and protein turnover in skeletal muscle. Calpains exist in two major forms. Interestingly, the two forms of protease show no significant difference in their action on various substrates.

Direct Analysis of Resveratrol in Wine by Micellar Electrokinetic Capillary Electrophoresis.

Resveratrol is an antioxidant found in grapes and other plants. It has been reported to have health benefits including anticarcinogenic activity and protection against coronary heart disease. Previous methods for its quantification in wines have relied on HPLC and GC.

Soybean glycinin G1 acidic chain shares IgE epitopes with peanut allergen Ara h 3.

Background: The identification of IgE epitopes for proteins is the first step in understanding the interaction of allergens with the immune system. Proteins from the legume family have shown in vitro cross-reactivity in IgE-binding assays, but this cross-reactivity is rarely clinically significant. Resolution of this discrepancy requires IgE epitope mapping of legume family protein allergens.

Analysis of resveratrol in wine by capillary electrophoresis.

Capillary electrophoresis (CE) is a new analytical technique that has recently been reported as a method for analysis of resveratrol in wine. Several different separation approaches have been taken in these reports. In comparison with high-performance liquid chromatography (HPLC), CE methods have similar sensitivity and can discriminate between trans- and cis-isomers of resveratrol.

Capillary electrophoretic determination of resveratrol in wines.

A rapid and sensitive capillary electrophoretic method for analysis of resveratrol in wine was established. The protocol consists of sample preparation using a C-18 solid-phase extraction cartridge. Baseline separation of trans- and cis-resveratrol from other compounds in wine was achieved in approximately 8 min using a micellar mode.

Capillary electrophoretic determination of cathepsin D activity using Oregon Green-labeled hemoglobin.

Cathepsin D is an aspartyl protease of lysosomal origin and functions in a variety of roles including protein turnover, catabolism of peptide hormones, antigen processing and presentation, and neoplastic disease. In breast cancer, the level of cathepsin D has been linked to metastasis and prognosis for survivability. Many of these studies concerning the role of cathepsin D in cancer have used immunological detection methods to determine the level of enzyme.

Quantitative separation of 4-hydroxyproline from skeletal muscle collagen by micellar electrokinetic capillary electrophoresis.

The phenylthiohydantoin (PTH) derivatives of 3- and 4-hydroxyproline (Hyp) were separated using micellar electrokinetic capillary electrophoresis (MEKC). The separation protocol was also used to determine Hyp content of bovine skeletal perimysial collagen preparations and whole muscle samples. Amino acids from hydrolyzed tissues were labeled using a two step procedure that involved initial reaction with o-phthalaldehyde (OPA) to modify primary amines followed by their precipitation under acidic conditions.

Capillary electrophoretic analysis of cathepsin D action on hemoglobin.

The action of purified cathepsin D on hemoglobin was examined using micellar electrokinetic chromatographic separation of peptide products. Purified cathepsin D was incubated with hemoglobin in 40 mM Na-formate pH 3.1 at 37 degrees C for varying lengths of time.

Conditions for the culture of bovine embryonic myogenic cells.

The objective of this experiment was to determine the growth characteristics of bovine embryonic muscle cells and to optimize the growth conditions for these cells using commercially-prepared media and sera. In the first study, the growth of muscle cells isolated from the hindlimb was determined by measuring DNA content. The DNA concentration was lowest (P < 0.

Determination of 3-methylhistidine by capillary electrophoresis.

The post-translational methylation of histidine to form 3-methylhistidine (3MH) is a modification principally found in contractile proteins, and thus, the level of free 3MH has been used to monitor muscle protein turnover. This work describes procedures for the capillary electrophoretic separation and determination of the phenylthiohydantoin (PTH) derivative of 3MH using uncoated fused-silica capillaries. The procedure described here utilized UV detection and resulted in a linear standard curve in the range of 2-15 pmole, which is more sensitive than previously reported HPLC methods using fluorescent detection.

Analysis of endoproteinase Arg C action on adrenocorticotrophic hormone by capillary electrophoresis and reversed-phase high-performance liquid chromatography.

The specificity and rate of cleavage of adrenocorticotrophic hormone (ACTH) peptide bonds by endoproteinase Arg C were analyzed using capillary electrophoresis (CE) and reversed-phase (C18) high-performance liquid chromatography (HPLC). Acidic cleavage products were readily resolved by CE in uncoated capillaries using low ionic strength electrolytes. However, products predicted to have a net positive charge greater than 2 or more than 4 positively charged groups per peptide did not migrate out from the capillary at low ionic strength.

Determination of native folates in milk and other dairy products by high-performance liquid chromatography.

Folates were measured in dairy products by high-performance liquid chromatography without prior sample clean-up. Detection limits for individual folates range from 0.3 to 7.

Interaction of alpha-actinin, filamin and tropomyosin with F-actin.

The abilities of alpha-actinin, filamin and tropomyosin to bind F-actin were examined by cosedimentation experiments. Results indicated that smooth muscle alpha-actinin and filamin can bind to actin filaments simultaneously with little evidence of competition. In contrast, tropomyosin exhibits marked competition with either filamin or alpha-actinin for sites on actin filaments.

A Ca2+-activated protease possibly involved in myofibrillar protein turnover. Purification from porcine muscle.

Ca2+-activated Z-disk-removing activity in the P0-40 crude muscle extracts described by Busch et al. (Busch, W. A.