Tropomyosin micelles are the major white components in the boiled soup of shellfish

Basket clam soup, a popular Asian dish, is prepared by boiling clams in hot water. The soup is generally cloudy and considered more delicious as cloudiness increases. However, the identity of the whitening ingredients and their relationship with taste remain unclear. In this study, we aimed to identify the components that contribute to the white color of the boiled soup. The white component was precipitated with trichloroacetic acid and reacted positively with ninhydrin, indicating the presence of proteins. The proteins were separated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and an intense band was observed at 33 kDa. Peptide mass fingerprinting of this band using matrix-assisted laser desorption/ionisation-time-of-flight tandem mass spectrometry revealed the protein to be tropomyosin. Basket clam tropomyosin expressed and purified from Escherichia coli turned the extracted solution white, confirming that tropomyosin contributed to the white color of clam soup.

Tropomyosin micelles are the major white components in the boiled soup of shellfish

Basket clam soup, a popular Asian dish, is prepared by boiling clams in hot water. The soup is generally cloudy and considered more delicious as cloudiness increases. However, the identity of the whitening ingredients and their relationship with taste remain unclear. In this study, we aimed to identify the components that contribute to the white color of the boiled soup. The white component was precipitated with trichloroacetic acid and reacted positively with ninhydrin, indicating the presence of proteins. The proteins were separated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and an intense band was observed at 33 kDa. Peptide mass fingerprinting of this band using matrix-assisted laser desorption/ionisation-time-of-flight tandem mass spectrometry revealed the protein to be tropomyosin. Basket clam tropomyosin expressed and purified from Escherichia coli turned the extracted solution white, confirming that tropomyosin contributed to the white color of clam soup.

Trichloroacetic Acid/Acetone Precipitation Method to Optimize Canine Synovial Fluid for One and Two-Dimensional Gel Electrophoresis Studies

The challenge associated with the use of synovial fluid for osteoarthritic proteome studies is the optimization step, which involves the depletion of high abundant proteins from the samples. The objective of this study was to develop a cost efficient and effective method to remove albumin from canine synovial fluid for proteome studies. Pooled synovial fluid samples were obtained from clinically healthy dogs (n=5), with no radiographic features of osteoarthritis. The acetone precipitation method and 10% w/v of trichloroacetic acid/acetone were chosen to deplete the albumin from canine synovial fluid and the outcome from the different methods were compared using one dimensional and two-dimensional gel electrophoresis studies. The results showed that the 10% w/v TCA/acetone precipitation method removed highly abundant proteins from synovial fluid for gel electrophoresis studies compared to the acetone precipitation method. The 10% w/v TCA/acetone precipitation method provides an effective method to remove albumin from the synovial fluid using gel electrophoresis, especially two-dimensional gel electrophoresis. The accessibility and cost of TCA and acetone make this method of precipitation a simple and cost-effective technique in preparing a canine synovial fluid for two-dimensional gel electrophoresis analysis.

Molecular mechanisms underlying the effect of diacerein on trichloroacetic acid–induced hepatic pre-neoplastic lesions in rats

Hepatocellular carcinoma (HCC) accounts for more than 5% of all human cancers. Diacerein (DIA), an interleukin (IL)-1β inhibitor, is used for the treatment of osteoarthritis. DIA is a potential anticancer drug acting on several protein targets in the process of apoptosis. The present study aimed to explore the molecular mechanisms underlying the effect of DIA in the treatment of trichloroacetic acid (TCA)–induced pre-neoplastic changes in rats. Rats were allocated into 5 groups and treated for 4 weeks. Group 1: control; received vehicle, Group 2: TCA group; received TCA (1 g/kg, orally for 5 days). Group 3: DIA-treated group; received TCA +DIA (50 mg/kg/day, orally, for 4 weeks). Group 4: positive control group; received TCA (1 g/kg, orally, for 5 days) + 5-fluorouracil (5-FU) (75 mg/kg) intraperitoneally (i.p.), for 4 weeks as a standard anticancer drug. Group 5: received TCA (1 g/kg, orally for 5 days) + DIA (50 mg/kg/day, orally, for 4 weeks) + 5-FU (75 mg/kg, i.p., for 4 weeks). Serum liver enzymes, oxidative stress parameters, inflammatory parameter (IL-1β), and angiogenesis marker vascular endothelial growth factor (VEGF) were assessed along with histopathological evaluation. An apoptotic marker as caspase-3 expression was measured by western blot analysis. Immunoexpression of proliferating cell nuclear antigen (PCNA) and hypoxia-inducible factor-1α (HIF-1α) was evaluated. Results and conclusion: The outcomes proved that at histological level, DIA ameliorated hepatic precancerous lesion via modulation of IL-1β–HIF-1α–VEGF pathway. Conclusion IL-1β mediates angiogenesis indirectly, as it has been shown to induce hypoxia-inducible factor-1α (HIF-1α) which upregulates VEGF.

Comparative study of technologies for extraction of biologically active substances from the raw material of animal origin

Technologies of isolation and concentration of biologically active substances, developed in the middle of the 20th century, need adjustment and adaptation to modern conditions both to increase the activity of substances and for greater economic efficiency. The aim of the research is the comparison of dynamics of biologically active compounds extraction from porcines pancreas in two methods: the saline method based on 0.9% sodium chloride solution, and the acidic method based on 2.4% trichloroacetic acid solution. Also the purpose of research is to assess the possibilities for further optimization of technologies. The total protein concentration based on the biuret reaction in the samples taken during the extraction, as well as the calculation and analysis of the point degrees and rates of extraction are chosen as the controlled parameters. Local maxima of the protein yields into the extractant media at the 60th, 135th and 255th minute were recorded during saline extraction; and at the 75th and 135th minute during acid extraction. Also the proteomic profile of the extracts was studied. Wide range of compounds with molecular weight of less than 52 kDa was found in extracts based on physiological saline solution, and protein substances of whole presented range of molecular weights in trichloroacetic acid based extracts were considered. The predominance of low molecular weight protein fraction of interest was noted also in this method of extraction in comparison with the other methods of extraction. According to the UniProt database, we assume availability of probable compounds with a molecular weight of less than 30 kDa in the purified acidic extract. The presence of some proteins absent in the final saline extract was noted. The acidic erythrograms showed a weak degrading effect of both types of extracts on the membranes of rat erythrocytes, as well as the cytoprotective effect of acidic ultrafiltrates (less than 3 kDa). The obtained results prove a better efficiency of trichloroacetic acid extraction method used for obtaining a mixture of a wide range of compounds, including biologically active substances of low molecular weight.

Pumping Between Phases With a Pulsed-Fuel Molecular Ratchet

The sorption of species from solution into and onto solids, surfaces, crystals, gels and other matrices, underpins the sequestering of waste and pollutants, the recovery of precious metals, heterogeneous catalysis, many forms of chemical and biological analysis and separation science, and numerous other technologies. In such cases the transfer of the substrate between phases tends to proceed spontaneously, in the direction of equilibrium. Molecular ratchet mechanisms, where kinetic gating selectively inhibits or accelerates particular steps in a process, makes it possible to drive dynamic systems out of equilibrium. Here we report on a small-molecule pump immobilised on and near the surface of polymer beads, that uses an energy ratchet mechanism to actively transport substrates from solution onto the beads away from equilibrium. One complete cycle of the pump occurs with each pulse of a chemical fuel, synchronizing the ratchet dynamics so that the immobilised molecular machines all act in unison. Upon addition of the trichloroacetic acid fuel, micrometre-diameter polystyrene beads functionalised with an average of ~8×10exp10 molecular pumps per bead, sequester from solution crown ethers appended with a fluorescent tag. Following consumption of the fuel, the rings are mechanically trapped in a higher energy, out-of-equilibrium, state on the beads and cannot be removed by dilution nor by switching the binding interactions off. This differs from dissipative assembled materials that require a continuous supply of energy to persist. Addition of a second pulse of fuel causes the uptake of more macrocycles, which can be labelled with a different fluorescent tag. This drives the system progressively further away from equilibrium and also confers sequence information on the deposited structure. The polymer-bound substrates (and the stored energy) can subsequently be released back to the bulk on demand, either emptying one compartment at a time or all at once. Non-equilibrium sorption by using immobilised artificial molecular machines to pump substrates from solution onto and into materials, offers potential for the transduction of energy from chemical fuels for the storage and release of energy and information.

Laboratory Practices for Purification of Polysaccharide

The aim of the present work is to purify the mucilage polysaccharide extracted from linseed by deproteinization using Trichloroacetic acid (TCA) and Hydochloric acid (Hcl). 10% w/v TCA deproteinized more than 80% when the pH of the polysaccharide solution was 3. TCA can be considered as an better deproteinizing agent when compared to hydrochloric acid as evidenced by the highest deproteinization efficiency (88.57%)