Displaying publications 1 - 20 of 46 in total

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  1. Al-Sheraji SH, Ismail A, Manap MY, Mustafa S, Yusof RM
    J Food Sci, 2012 Nov;77(11):M624-30.
    PMID: 23106104 DOI: 10.1111/j.1750-3841.2012.02955.x
    The viability and activity of Bifidobacterium pseudocatenulatum G4, B. longum BB 536 and yoghurt cultures (Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus) were studied in yoghurt containing 0.75% Mangefira pajang fibrous polysaccharides (MPFP) and inulin. Growth of probiotic organisms, their proteolytic activities, the production of short chain fatty acids (lactic, acetic and propionic) and the pH of the yoghurt samples were determined during refrigerated storage at 4 °C for 28 d. B. pseudocatenulatum G4 and B. longum BB 536 showed better growth and activity in the presence of MPFP and inulin, which significantly increased the production of short chain fatty acids as well as the proteolytic activity of these organisms.
    Matched MeSH terms: Proteolysis
  2. Xu Z, Nan W, Zhang X, Sun Y, Yang J, Lu K, et al.
    J Mol Neurosci, 2018 Jun;65(2):222-233.
    PMID: 29845511 DOI: 10.1007/s12031-018-1075-5
    Mesenchymal stem cell (MSC) therapy is a promising prospect for the treatment of Alzheimer's disease (AD); however, the underlying mechanisms by which MSCs mediate positive effects are still unclear. We speculated that MSCs mediate microglial autophagy and enhance the clearance of Aβ. To test this hypothesis, we cultured BV2 microglial cells with umbilical cord mesenchymal stem cells conditioned medium (ucMSCs-CM) in the presence or absence of Aβ25-35 oligomers. We investigated BV2 cell proliferation, cell death, and Aβ25-35 phagocytosis as well as protein expression levels of LC3, Beclin-1, p62, insulin-degrading enzyme (IDE), and neprilysin (Nep) with western blotting. The results showed that ucMSCs-CM inhibited the proliferation and decreased cell death of BV2 cells induced by Aβ25-35. ucMSCs-CM also promoted the phagocytosis of Aβ25-35 by BV2 cells and changed the expression of autophagy-related proteins LC3, Beclin-1, and p62. Treatment also upregulated the expression of Aβ-degrading enzymes IDE and Nep. Furthermore, the culture medium in BV2 cells with Aβ25-35 and ucMSCs-CM prevented neuronal cell SH-SY5Y from cell death compared to control medium without ucMSCs-CM. Altogether, these data suggested that ucMSCs-CM protect microglial and neuronal cells from Aβ25-35-induced cell death and promote Aβ phagocytosis by modulating autophagy and enhancing the expression of Aβ-degrading enzymes in microglia.
    Matched MeSH terms: Proteolysis*
  3. Loganathan R, Selvaduray KR, Nesaretnam K, Radhakrishnan AK
    Cell Prolif, 2013 Apr;46(2):203-13.
    PMID: 23510475 DOI: 10.1111/cpr.12014
    OBJECTIVES: Tocotrienols and tocopherols are members of the vitamin E family, with similar structures; however, only tocotrienols have been reported to achieve potent anti-cancer effects. The study described here has evaluated anti-cancer activity of vitamin E to elucidate mechanisms of cell death, using human breast cancer cells.

    MATERIALS AND METHODS: Anti-cancer activity of a tocotrienol-rich fraction (TRF) and a tocotrienol-enriched fraction (TEF) isolated from palm oil, as well as pure vitamin E analogues (α-tocopherol, α-, δ- and γ-tocotrienols) were studied using highly aggressive triple negative MDA-MB-231 cells and oestrogen-dependent MCF-7 cells, both of human breast cancer cell lines. Cell population growth was evaluated using a Coulter particle counter. Cell death mechanism, poly(ADP-ribose) polymerase cleavage and levels of NF-κB were determined using commercial ELISA kits.

    RESULTS: Tocotrienols exerted potent anti-proliferative effects on both types of cell by inducing apoptosis, the underlying mechanism of cell death being ascertained using respective IC50 concentrations of all test compounds. There was marked induction of apoptosis in both cell lines by tocotrienols compared to treatment with Paclitaxel, which was used as positive control. This activity was found to be associated with cleavage of poly(ADP-ribose) polymerase (a DNA repair protein), demonstrating involvement of the apoptotic cell death signalling pathway. Tocotrienols also inhibited expression of nuclear factor kappa-B (NF-κB), which in turn can increase sensitivity of cancer cells to apoptosis.

    CONCLUSION: Tocotrienols induced anti-proliferative and apoptotic effects in association with DNA fragmentation, poly(ADP-ribose) polymerase cleavage and NF-κB inhibition in the two human breast cancer cell lines.

    Matched MeSH terms: Proteolysis*
  4. Bhowmick S, Chakravarty C, Sellathamby S, Lal SK
    Arch Virol, 2017 Apr;162(4):919-929.
    PMID: 27942972 DOI: 10.1007/s00705-016-3153-8
    The matrix protein 2 (M2) is a spliced product of segment 7 genome of influenza A virus. Previous studies indicate its role in uncoating of the viral ribonucleoprotein complex during viral entry and in membrane scission while budding. Despite its crucial role in the viral life cycle, little is known about its subcellular distribution and dynamics. In this study, we have shown that the M2 protein is translocated from the membrane to the cytoplasm by a retrograde route via endosomes and the Golgi network. It utilizes retromer cargo while moving from the endosome to the trans-Golgi network and prevents endosome fusion with the lysosome. Further, M2 interacts with the endoplasmic-reticulum-resident AAA-ATPase p97 for its release into the cytoplasm. Our study also revealed that the M2 protein in the cellular milieu does not undergo ubiquitin-mediated proteasomal degradation. The migration of M2 through this pathway inside the infected cell suggests possible new roles that the M2 protein may have in the host cytoplasm, apart from its previously described functions.
    Matched MeSH terms: Proteolysis
  5. Bordbar S, Ebrahimpour A, Abdul Hamid A, Abdul Manap MY, Anwar F, Saari N
    Biomed Res Int, 2013;2013:849529.
    PMID: 23586061 DOI: 10.1155/2013/849529
    The stone fish (Actinopyga lecanora) ethanolic and methanolic tissue extracts were investigated for total phenolic contents (TPCs) as well as antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH(•)) radical scavenging activity and ferric reducing antioxidant power (FRAP) assays. Both extracts showed low amount of phenolics (20.33 to 17.03 mg of gallic acid equivalents/100 g dried sample) and moderate antioxidant activity (39% to 34% DPPH(•) radical scavenging activity and 23.95 to 22.30 mmol/100 mL FeSO4 FRAP value). Enzymatic proteolysis was carried out in order to improve the antioxidant activity using six commercially available proteases under their optimum conditions. The results revealed that the highest increase in antioxidant activity up to 85% was obtained for papain-generated proteolysate, followed by alcalase (77%), trypsin (75%), pepsin (68%), bromelain (68%), and flavourzyme (50%) as measured by DPPH(•) radical scavenging activity, whilst for the FRAP value, the highest increase in the antioxidant activity up to 39.2 mmol/100 mL FeSO4 was obtained for alcalase-generated proteolysate, followed by papain (29.5 mmol/100 mL FeSO4), trypsin (23.2 mmol/100 mL FeSO4), flavourzyme (24.7 mmol/100 mL FeSO4), bromelain (22.9 mmol/100 mL FeSO4), and pepsin (20.8 mmol/100 mL FeSO4). It is obvious that proteolysis of stone fish tissue by proteolytic enzymes can considerably enhance its antioxidant activity.
    Matched MeSH terms: Proteolysis*
  6. Shori AB, Ming KS, Baba AS
    Biotechnol Appl Biochem, 2021 Apr;68(2):221-229.
    PMID: 32249982 DOI: 10.1002/bab.1914
    Plain and Lycium barbarum yogurt were made in the presence and absence of fish collagen. Yogurt samples were analyzed for acidification, milk protein proteolysis, angiotensin I-converting enzyme (ACE) inhibitory activity, and sensory evaluation during refrigerated storage for up to 21 days. The o-phthaldialdehyde peptides amount of L. barbarum yogurt both in the presence and absence of fish collagen were significantly increased during 14 days of storage. SDS-PAGE showed improvement in whey proteins degradation of L. barbarum yogurt with/without fish collagen after 3 weeks of storage. L. barbarum yogurt in absence of fish collagen was acting as a great ACE inhibitor reached up to 85% on day 7 of storage. The incorporation of L. barbarum and/or fish collagen affected to a small extent the overall sensory characteristics of yogurt. Yogurt supplemented with L. barbarum and/or fish collagen may lead to the improvement in the production and formulation of yogurt differing in their anti-ACE activity.
    Matched MeSH terms: Proteolysis*
  7. Siddiqui R, Saleem S, Khan NA
    Exp Parasitol, 2016 Jun 18;168:16-24.
    PMID: 27327524 DOI: 10.1016/j.exppara.2016.06.006
    The treatment of Acanthamoeba infections remains problematic, suggesting that new targets and/or chemotherapeutic agents are needed. Bioassay-guided screening of drugs that are clinically-approved for non-communicable diseases against opportunistic eukaryotic pathogens is a viable strategy. With known targets and mode of action, such drugs can advance to clinical trials at a faster pace. Recently Bortezomib (proteasome inhibitor) has been approved by FDA in the treatment of multiple myeloma. As proteasomal pathways are well known regulators of a variety of eukaryotic cellular functions, the overall aim of the present study was to study the effects of peptidic and non-peptidic proteasome inhibitors on the biology and pathogenesis of Acanthamoeba castellanii of the T4 genotype, in vitro. Zymographic assays revealed that inhibition of proteasome had detrimental effects on the extracellular proteolytic activities of A. castellanii. Proteasome inhibition affected A. castellanii growth (using amoebistatic assays), but not viability of A. castellanii. Importantly, proteasome inhibitors affected encystation as determined by trophozoite transformation into the cyst form, as well as excystation, as determined by cyst transformation into the trophozoite form. The ability of proteasome inhibitor to block Acanthamoeba differentiation is significant, as it presents a major challenge in the successful treatment of Acanthamoeba infection. As these drugs are used clinically against non-communicable diseases, the findings reported here have the potential to be tested in a clinical setting against amoebic infections.
    Matched MeSH terms: Proteolysis
  8. Yeo EH, Goh WL, Chow SC
    Toxicol. Mech. Methods, 2018 Mar;28(3):157-166.
    PMID: 28849708 DOI: 10.1080/15376516.2017.1373882
    The leucine aminopeptidase inhibitor, benzyloxycarbonyl-leucine-chloromethylketone (z-L-CMK), was found to be toxic and readily induce cell death in Jurkat T cells. Dose-response studies show that lower concentration of z-L-CMK induced apoptosis in Jurkat T cells whereas higher concentration causes necrosis. In z-L-CMK-induced apoptosis, both the initiator caspases (-8 and -9) and effector caspases (-3 and -6) were processed to their respective subunits. However, the caspases remained intact in z-L-CMK-induced necrosis. The caspase inhibitor, z-VAD-FMK inhibited z-L-CMK-mediated apoptosis and caspase processing but has no effect on z-L-CMK-induced necrosis in Jurkat T cells. The high mobility group protein B1 (HMGB1) protein was found to be released into the culture medium by the necrotic cells and not the apoptotic cells. These results indicate that the necrotic cell death mediated by z-L-CMK at high concentrations is via classical necrosis rather than secondary necrosis. We also demonstrated that cell death mediated by z-L-CMK was associated with oxidative stress via the depletion of intracellular glutathione (GSH) and increase in reactive oxygen species (ROS), which was blocked by N-acetyl cysteine. Taken together, the results demonstrated that z-L-CMK is toxic to Jurkat T cells and induces apoptosis at low concentrations, while at higher concentrations the cells die of necrosis. The toxic side effects in Jurkat T cells mediated by z-L-CMK are associated with oxidative stress via the depletion of GSH and accumulation of ROS.
    Matched MeSH terms: Proteolysis/drug effects
  9. Kar R, Jha SK, Ojha S, Sharma A, Dholpuria S, Raju VSR, et al.
    Cancer Rep (Hoboken), 2021 08;4(4):e1369.
    PMID: 33822486 DOI: 10.1002/cnr2.1369
    BACKGROUND: Ubiquitin ligases or E3 ligases are well programmed to regulate molecular interactions that operate at a post-translational level. Skp, Cullin, F-box containing complex (or SCF complex) is a multidomain E3 ligase known to mediate the degradation of a wide range of proteins through the proteasomal pathway. The three-dimensional domain architecture of SCF family proteins suggests that it operates through a novel and adaptable "super-enzymatic" process that might respond to targeted therapeutic modalities in cancer.

    RECENT FINDINGS: Several F-box containing proteins have been characterized either as tumor suppressors (FBXW8, FBXL3, FBXW8, FBXL3, FBXO1, FBXO4, and FBXO18) or as oncogenes (FBXO5, FBXO9, and SKP2). Besides, F-box members like βTrcP1 and βTrcP2, the ones with context-dependent functionality, have also been studied and reported. FBXW7 is a well-studied F-box protein and is a tumor suppressor. FBXW7 regulates the activity of a range of substrates, such as c-Myc, cyclin E, mTOR, c-Jun, NOTCH, myeloid cell leukemia sequence-1 (MCL1), AURKA, NOTCH through the well-known ubiquitin-proteasome system (UPS)-mediated degradation pathway. NOTCH signaling is a primitive pathway that plays a crucial role in maintaining normal tissue homeostasis. FBXW7 regulates NOTCH protein activity by controlling its half-life, thereby maintaining optimum protein levels in tissue. However, aberrations in the FBXW7 or NOTCH expression levels can lead to poor prognosis and detrimental outcomes in patients. Therefore, the FBXW7-NOTCH axis has been a subject of intense study and research over the years, especially around the interactome's role in driving cancer development and progression. Several studies have reported the effect of FBXW7 and NOTCH mutations on normal tissue behavior. The current review attempts to critically analyze these mutations prognostic value in a wide range of tumors. Furthermore, the review summarizes the recent findings pertaining to the FBXW7 and NOTCH interactome and its involvement in phosphorylation-related events, cell cycle, proliferation, apoptosis, and metastasis.

    CONCLUSION: The review concludes by positioning FBXW7 as an effective diagnostic marker in tumors and by listing out recent advancements made in cancer therapeutics in identifying protocols targeting the FBXW7-NOTCH aberrations in tumors.

    Matched MeSH terms: Proteolysis
  10. Zhou C, Wu X, Pan D, Xia Q, Sun Y, Geng F, et al.
    Food Chem, 2024 Mar 15;436:137711.
    PMID: 37839122 DOI: 10.1016/j.foodchem.2023.137711
    To understand the mechanism of co-inoculation of Staphylococcus xylosus and Staphylococcus vitulinus (SX & SV) on structural protein degradation and taste enhancement of dry-cured bacon, protease activities, protein degradation, surface morphology of proteins and taste parameters of dry-cured bacon with Staphylococcus inoculation were investigated. The dry-cured bacon with co-inoculation of Staphylococcus xylosus and Staphylococcus vitulinus showed the best taste attributes. High residual activities in cathepsin B + L (more than 1.6-fold) and alanyl aminopeptidase (more than 1.4-fold) accelerated structural protein degradation in SX & SV. 32 down-regulated proteins were identified in SX & SV by TMT-labeled quantitative proteomic compared with control group; myosin and actin showed the most intense response to the accumulation of sweet and umami amino acids, and atomic force microscopy confirmed structural proteins breakdown by morphological changes. The accumulation of glutamic acid, alanine and lysine was mainly responsible for taste improvement of dry-cured bacon with Staphylococcus co-inoculation.
    Matched MeSH terms: Proteolysis
  11. Acquah C, Chan YW, Pan S, Agyei D, Udenigwe CC
    J Food Biochem, 2019 01;43(1):e12765.
    PMID: 31353493 DOI: 10.1111/jfbc.12765
    The application of proteomic and peptidomic technologies for food-derived bioactive peptides is an emerging field in food sciences. These technologies include the use of separation tools coupled to a high-resolution spectrometric and bioinformatic tools for prediction, identification, sequencing, and characterization of peptides. To a large extent, one-dimensional separation technologies have been extensively used as a continuous tool under different optimized conditions for the identification and analysis of food peptides. However, most one-dimensional separation technologies are fraught with significant bottlenecks such as insufficient sensitivity and specificity limits for complex samples. To address this limitation, separation systems based on orthogonal, multidimensional principles, which allow for the coupling of more than one analytical separation tool with different operational principles, provide a higher separation power than one-dimensional separation tools. This review describes the structure-informed separation and purification of protein hydrolyzates to obtain peptides with desirable bioactivities. PRACTICAL APPLICATIONS: Application of bioactive peptides in the formulation of functional foods, nutraceuticals, and therapeutic agents have increasingly gained scholarly and industrial attention. The bioactive peptides exist originally in protein sources and are only active after hydrolysis of the parent protein. Currently, several tools can be configured in one-dimensional or multidimensional systems for the separation and purification of protein hydrolyzates. The separations are informed by the structural properties such as the molecular weight, charge, hydrophobicity or hydrophilicity, and the solubility of peptides. This review provides a concise discussion on the commonly used analytical tools, their configurations, advantages and challenges in peptide separation. Emphasis is placed on how the structural properties of peptides assist in the separation and purification processes and the concomitant effect of the separation on peptide bioactivity.
    Matched MeSH terms: Proteolysis
  12. Saadi S, Saari N, Abdulkarim MS, Ghazali HM, Anwar F
    J Control Release, 2018 03 28;274:93-101.
    PMID: 29031897 DOI: 10.1016/j.jconrel.2017.10.011
    Cell impurities are an emerging nucleating molecular barriers having the capability in disordering the metabolic chain reactions of proteolysis, glycolysis and lipolysis. Their massive effects induced by copolymer crystal growth in compaction with metal and mineral transients are extended as well as in damaging DNA and mRNA structure motif and other molecular assembly e.g. histones structure unites. Their polycrystalline packing modes, polydispersity and their tendency to surface and interface adhesion prompted us in structuring scaffold biomaterials enriched with biopeptides, layered by phospho-glycerides ester-forms. The interface tension of the formed map is flexible and dependent to the surface exposure and its collapse modes to the surrounding molecular ligands. Thus, the attempts in increasing surface exposure e.g. the viscoelastic of structured lipopeptides and types of formed network structures interplays an extra- conjugating biomolecules having a least cytotoxicity effects to cells constituents. Disulfides molecules are selected to be the key regulatory element in rejoining both lipidic and proteic moieties by disordering atoms status via chemical ionization using organic catalyst. The insertion of methionine based peptidic chain at the lateral surfaces of scaffold biomaterials enhances the electron-meta-static motions by raising a molecular disordering status at distinct regions of the map e.g. epimerization into a nonpolar side that helps the chemical conjunction of disulfide groups with the esterified phosphoglycerides mono-layers. These effects in turn are accomplished by the formation of meso-sphere nonpolar- vesicles. The oxidation of disulfide group would alter the ordering of initial molecules by raising a newly molecular disorders to the map with high polarity to surface regions. In the same time indicates a continuation in the crystallization growth factor via a low chemical lesions between the impurities and a supersaturation in the intra-atomic distances with maximum cross linking to the deformed ligand with scaffold biomaterials.
    Matched MeSH terms: Proteolysis
  13. M. J. Khatun, T.C. Loh, H.L. Foo, M.K.I. Khan
    MyJurnal
    Amino acids are known as anabolic factors that are essential for formation of muscle by stimulating protein synthesis while inhibiting proteolysis, and they are significant component for the synthesis of various nitrogenous compounds. There are 20 amino acids are essential to require in cell for formation of body protein of which about 10 amino acids, which cannot be synthesized by the birds are termed essential. Among the essential amino acid arginine one of the essential amino acids for chickens because, like other birds, they are unable to obtain Arginine from endogenous sources due to the absence of most of the enzymes involved in the urea cycle. This amino acid involved in synthesis of proline, hydroxyl proline and polyamines which are essential for connective tissue synthesis as well as increased growth of chicken. Moreover, L-arginine (L-Arg) is effective for reducing fat deposition in broiler. Moreover, it decrease heat stress increase meat quality and increase immune response of broiler. This re-view presents the recent advances in the relevance of the inclusion of excess L-Arginine in broiler ration to growth, fat deposition and immune response in broiler.
    Matched MeSH terms: Proteolysis
  14. Selvaraj BA, Mariatulqabtiah AR, Ho KL, Ng CL, Yong CY, Tan WS
    Int J Mol Sci, 2021 Aug 13;22(16).
    PMID: 34445426 DOI: 10.3390/ijms22168725
    The causative agent of white tail disease (WTD) in the giant freshwater prawn is Macrobrachium rosenbergii nodavirus (MrNV). The recombinant capsid protein (CP) of MrNV was previously expressed in Escherichia coli, and it self-assembled into icosahedral virus-like particles (VLPs) with a diameter of approximately 30 nm. Extensive studies on the MrNV CP VLPs have attracted widespread attention in their potential applications as biological nano-containers for targeted drug delivery and antigen display scaffolds for vaccine developments. Despite their advantageous features, the recombinant MrNV CP VLPs produced in E. coli are seriously affected by protease degradations, which significantly affect the yield and stability of the VLPs. Therefore, the aim of this study is to enhance the stability of MrNV CP by modulating the protease degradation activity. Edman degradation amino acid sequencing revealed that the proteolytic cleavage occurred at arginine 26 of the MrNV CP. The potential proteases responsible for the degradation were predicted in silico using the Peptidecutter, Expasy. To circumvent proteolysis, specific protease inhibitors (PMSF, AEBSF and E-64) were tested to reduce the degradation rates. Modulation of proteolytic activity demonstrated that a cysteine protease was responsible for the MrNV CP degradation. The addition of E-64, a cysteine protease inhibitor, remarkably improved the yield of MrNV CP by 2.3-fold compared to the control. This innovative approach generates an economical method to improve the scalability of MrNV CP VLPs using individual protease inhibitors, enabling the protein to retain their structural integrity and stability for prominent downstream applications including drug delivery and vaccine development.
    Matched MeSH terms: Proteolysis/drug effects
  15. Saadi S, Saari N, Anwar F, Abdul Hamid A, Ghazali HM
    Biotechnol Adv, 2014 12 12;33(1):80-116.
    PMID: 25499177 DOI: 10.1016/j.biotechadv.2014.12.003
    The growing momentum of several common life-style diseases such as myocardial infarction, cardiovascular disorders, stroke, hypertension, diabetes, and atherosclerosis has become a serious global concern. Recent developments in the field of proteomics offering promising solutions to solving such health problems stimulates the uses of biopeptides as one of the therapeutic agents to alleviate disease-related risk factors. Functional peptides are typically produced from protein via enzymatic hydrolysis under in vitro or in vivo conditions using different kinds of proteolytic enzymes. An array of biological activities, including antioxidative, antihypertensive, antidiabetic and immunomodulating has been ascribed to different types of biopeptides derived from various food sources. In fact, biopeptides are nutritionally and functionally important for regulating some physiological functions in the body; however, these are yet to be extensively addressed with regard to their production through advance strategies, mechanisms of action and multiple biological functionalities. This review mainly focuses on recent biotechnological advances that are being made in the field of production in addition to covering the mode of action and biological activities, medicinal health functions and therapeutic applications of biopeptides. State-of-the-art strategies that can ameliorate the efficacy, bioavailability, and functionality of biopeptides along with their future prospects are likewise discussed.
    Matched MeSH terms: Proteolysis
  16. Chai, L.C., Fatimah, C.A., Norhisyam, M.S., Rozila, A., Nadzirah, A.S., Natasha, L.H.Y.
    MyJurnal
    The objective of the present study was to develop a rapid, reliable and yet inexpensive protocol for genomic DNA extraction from frozen and ethanol-preserved Asian green-lipped mussels for random amplified microsatelite (RAM) analysis. The procedure comprised of three major steps: (1) Tissue degradation by boiling in 6% Chelex 100 resin in TE buffer; (2) Protein digestion by Proteinase K; and (3) DNA precipitation by adding 2 volumes of cold absolute ethanol. The entire procedure can be completed within two hours. The resulting RAM profiles were clear and reproducible. Our results demonstrate that the combined protocol of Chelex 100-Proteinase K-ethanol precipitation is a powerful yet economical DNA isolation method for population genetic studies involving a large sample size.
    Matched MeSH terms: Proteolysis
  17. Dahlan HM, Karsani SA, Rahman MA, Hamid NA, Top AG, Ngah WZ
    J Nutr Biochem, 2012 Jul;23(7):741-51.
    PMID: 21840697 DOI: 10.1016/j.jnutbio.2011.03.018
    Vitamin E has been suggested to modulate age-associated changes by altering the redox balance resulting in altered gene and/or protein expression. Here we have utilized proteomics to determine whether such regulation in protein expression occurs in human lymphocytes from two different age groups stressed with H₂O₂ and then treated with vitamin E in the form of tocotrienol-rich fraction (TRF). In this study, lymphocytes obtained from young (30-49 years old) and old (>50 years old) volunteers were first challenged with 1 mM H₂O₂. They were then treated by exposure to 50, 100 and 200 μg/ml TRF. Two-dimensional gel electrophoresis followed by MALDI-TOF/TOF (matrix-assisted laser desorption/ionization time-of-flight/time-of-flight) tandem mass spectrometry was then performed on whole-cell protein extracts to identify proteins that have changed in expression. A total of 24 proteins were found to be affected by H₂O₂ and/or TRF treatment. These included proteins that were related to metabolism, antioxidants, structural proteins, protein degradation and signal transduction. Of particular interest was the regulation of a number of proteins involved in stress response--peroxiredoxin-2, peroxiredoxin-3 and peroxiredoxin-6-all of which were shown to be down-regulated with H₂O₂ exposure. The effect was reversed following TRF treatment. The expression of peroxiredoxin-2 and peroxiredoxin-6 was confirmed by quantitative reverse transcriptase polymerase chain reaction. These results suggested that TRF directly influenced the expression dynamics of the peroxiredoxin-2, thus improving the cells ability to resist damage caused by oxidative stress.
    Matched MeSH terms: Proteolysis/drug effects
  18. Shori AB, Hong YC, Baba AS
    Food Res Int, 2021 05;143:110238.
    PMID: 33992351 DOI: 10.1016/j.foodres.2021.110238
    Four types of cheeses were prepared included plain- cheese (control), Codonopsis pilosula (CP)- cheese, plain- cheese with fish collagen (FC; control) and CP- cheese with FC. The effects of cheese samples on acidification, proteolysis of milk proteins using three methods (cadmium-ninhydrin method, O-phthaldialdehyde (OPA) assay, and electrophoresis assay), and angiotensin-converting enzyme (ACE)-inhibitory activity were investigated during 0, 2, & 4 weeks of ripening. In addition, the sensory evaluation was also investigated during 0, 2, 4, & 8 weeks of ripening. The presence of FC in CP- cheese increased the numbers of free amino acids (FAA) at 0 and 2 weeks. The addition of CP both in the presence and absence of FC affected positively (p 
    Matched MeSH terms: Proteolysis
  19. Handayani N, Achmad S, Miletic N, Loos K, Wahyuningrum D
    In spite of their excellent catalytic properties, enzymes should be improved before their implementation both in industrial and laboratorium scales. Immobilization of enzyme is one of the ways to improve their properties. Candida antarctica lipase B (Cal-B) has been reported in numerous publications to be a particularly useful enzyme catalizing in many type of reaction including regio- and enantio- synthesis. For this case, cross-linking of immobilized Cal-B with 1,2,7,8 diepoxy octane is one of methods that proved significantly more stable from denaturation by heat, organic solvents, and proteolysis than lyophilized powder or soluble enzymes. More over, the aim of this procedure is to improve the activity and reusability of lipase. Enzyme kinetics test was carried out by transesterification reaction between 4-nitrophenyl acetate (pNPA) and methanol by varying substrate concentrations, and the result is immobilized enzymes follows the Michaelis-Menten models and their activity is match with previous experiment. Based on the Vmax values, the immobilized enzymes showed higher activity than the free enzyme. Cross-linking of immobilized lipase indicate that cross-linking by lower concentration of cross-linker, FIC (immobilized lipase that was incubated for 24 h) gave the highest activity and cross-linking by higher concentration of cross-linker, PIC (immobilized lipase that was incubated for 2 h) gives the highest activity. However, pore size and saturation level influenced their activity.
    Matched MeSH terms: Proteolysis
  20. Zarei M, Ebrahimpour A, Abdul-Hamid A, Anwar F, Saari N
    Int J Mol Sci, 2012;13(7):8097-111.
    PMID: 22942692 DOI: 10.3390/ijms13078097
    The aim of this study was to produce a valuable protein hydrolysate from palm kernel cake (PKC) for the development of natural antioxidants. Extracted PKC protein was hydrolyzed using different proteases (alcalase, chymotrypsin, papain, pepsin, trypsin, flavourzyme, and bromelain). Subsequently, antioxidant activity and degree of hydrolysis (DH) of each hydrolysate were evaluated using DPPH• radical scavenging activity and O-phthaldialdehyde spectrophotometric assay, respectively. The results revealed a strong correlation between DH and radical scavenging activity of the hydrolysates, where among these, protein hydrolysates produced by papain after 38 h hydrolysis exhibited the highest DH (91 ± 0.1%) and DPPH• radical scavenging activity (73.5 ± 0.25%) compared to the other hydrolysates. In addition, fractionation of the most effective (potent) hydrolysate by reverse phase high performance liquid chromatography indicated a direct association between hydrophobicity and radical scavenging activity of the hydrolysates. Isoelectric focusing tests also revealed that protein hydrolysates with basic and neutral isoelectric point (pI) have the highest radical scavenging activity, although few fractions in the acidic range also exhibited good antioxidant potential.
    Matched MeSH terms: Proteolysis
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