• Title, Summary, Keyword: protein oxidation

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Free Radicals during the Oxidation and Reduction of Methylglyoxal-Modified Protein

  • Lee, Cheolju;Kang, Sa-Ouk
    • Proceedings of the Korean Biophysical Society Conference
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    • pp.36-36
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    • 1997
  • Protein glycation was studied with bovine serum albumin (BSA) as a model protein and methylglyoxal, a 3-carbon ${\alpha}$-ketoaldehyde. Methylglyoxal reacted with BSA, forming a radical as observed in the reaction of methylglyoxal wtih L-alanine or N-acetyl-L-lysine.(omitted)

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Antioxidant Effect of Korean Red Ginseng Extract on Aqueous Linoleic Acid and LDL (수용성계의 Linoleic Acid와 LDL에 대한 한국산 홍삼의 산화방지효과)

  • Lee, J.W.;Lee, S.K.;Do, J.H.;Sung, H.S.;Lee, H.O.
    • Applied Biological Chemistry
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    • v.40 no.4
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    • pp.283-288
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    • 1997
  • The antioxidant activities of Korean Red Ginseng Extract(RGE) and ${\alpha}-tocopherol$, as reference compound, were tested with HPLC and fluorometry which measure the MDA after reacting an aqueous 1% linoleic acid buffer solution, and LDL(1 mg protein/ml) buffer solution with $H_2O_2{\;}and{\;}FeCl_2$. The generation of conjugated-diene in LDL(0.25 mg protein/ml) was also measured by spectrometry. MDA determination showed the antioxidant effect on linoleic acid oxidation with oxidation inhibition ratio of 71.8% and 76.1%, respectively, by addition of 1000 ppm RGE and 100 ppm ${\alpha}-tocopherol$. LDL(1 mg protein/ml) oxidation was inhibited by 25.2% and 21.2%, respectively, by addition of 200 ppm REG and 100 ppm ${\alpha}-tocopherol$. The generation of conjugated diene in LDL(0.25 mg protein/ml) was also inhibited by 44.2%, by addition of 50 ppm RGE.

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Antioxidant effect of flavonoid, myricetin with GSH, vitamin E, vitamin C on B16F10, murine melanoma cell

  • Yu, Ji-Sun;Kim, An-Keun
    • Proceedings of the PSK Conference
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    • pp.144.2-144
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    • 2003
  • Reactive Oxygen Species (ROS) are produced during normal cellular function. ROS are very transient species due to their high chemical reactivity that leads to lipid peroxidation and oxidation of some enzyme, massive protein oxidation and degradation. Under normal conditions, antioxidant are substances that either directly or indirectly protect cells against adverse effects of ROS. Several biologically important compounds have been reported to have antioxidant functions. These incluce vitamin C, vitamin E, GSH, flavonoids. superoxidee dismutase(SOD), glutathione peroxidase(GPX) and catalase(CAT). (omitted)

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Purification and Characterization of Thiol-Specific Antioxidant Protein from Human Liver: A Mer5-Like Human Isoenzyme

  • Cha, Mee-Kyung;Kim, Il-Han
    • BMB Reports
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    • v.29 no.3
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    • pp.236-240
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    • 1996
  • A 23-kDa molecular mass of antioxidant protein was purified from human liver. This protein exhibited the preventive effect against the inactivation of glutamine synthetase by a metal-catalyzed oxidation system. This antioxidant activity was supported by a thiol-reducing equivalent such as dithiothreitol in a similar manner to that of the 25-kDa thiol-specific antioxidant protein (TSA) from human red blood cells (HR). However, a thioredoxin-linked peroxidase activity of thiol-specific antioxidant protein of human liver (HLTSA) (0.91 ${\mu}mol/min/nmol$ of HLTSA) was much lower than that of thiol-specific antioxidant protein of human red blood cells (HRTSA) (16.4 ${\mu}mol/min/nmol$ of HRTSA). This HLTSA is also immnologically distinct from HRTSA Amino acid sequences of the three tryptic peptides (P1, P2, P3) of HLTSA were found to be completely homologous to segments of the known Mer5-like protein, which belongs to the known TSA family.

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A Simulation Model for the protein Deposition of Pigs According to Amino Acid Composition of Feed Proteins (사료의 아미노산 조성에 따른 돼지의 단백질 축적을 나타내는 수치모델)

  • 이옥희;김강성
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.1
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    • pp.178-190
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    • 1999
  • This study was conducted to develop a simulation model for the growth dynamics of pigs and to describe quantitatively protein deposition depending on the amino acid composition of feed protein. In the model it is assumed that the essential processes that determine the utilization of feed protein in the whole body are protein synthesis, breakdown of protein, and oxidation of amino acid. Besides, it is also assumed that occurrence of protein deposition depends on genetic potential and amino acid composition of feed protein. The genetic potential for the protein deposition is the maximum capacity of protein synthesis, being dependent on the protein mass of the whole body. To describe the effect of amino acid composition of feed on the protein deposition, a factor, which consist of ten amino acid functions and lie between 0 and 1, is introduced. Accordingly a model was developed, which is described with 15 flux equations and 11 differential equations and is composed of two compartments. The model describes non linear structure of the protein utilization system of an organism, which is in non steady state. The objective function for the simulation was protein deposition(g/day) cal culated according to the empirical model, PAF(product of amino acid functions) of Menke. The mean of relative difference between the simulated protein deposition and PAF calculated values, lied in a range of 11.8%. The simulated protein synthesis and breakdown rates(g/day) in the whole body showed a parallel behavior in the course of growth.

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Imidazole Ring-Opened DNA Purines and Their Biological Significance

  • Barbara, Tudek
    • BMB Reports
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    • v.36 no.1
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    • pp.12-19
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    • 2003
  • Fragmentation of purine imidazole ring and production of formamidopyrimidines in deoxynucleosides (Fapy lesions) occurs upon DNA oxidation as well as upon spontaneous or alkali-triggered rearrangement of certain alkylated bases. Many chemotherapeutic agents such as cyclophosphamide or thiotepa produce such lesions in DNA. Unsubstituted FapyA and FapyG, formed upon DNA oxidation cause moderate inhibition of DNA synthesis, which is DNA polymerase and sequence dependent. Fapy-7MeG, a methylated counterpart of FapyG-, a efficiently inhibits DNA replication in vitro and in E.coli, however its mutagenic potency is low. This is probably due to preferential incorporation of cytosine opposite Fapy-7MeG and preferential extension of Fapy-7MeG:C pair. In contrast, FapyA and Fapy-7MeA possess miscoding potential. Both lesions in SOS induced E.coli preferentially mispair with cytosine giving rise to A$\rightarrow$G transitions. Fapy lesions substituted with longer chain alkyl groups also show simult aneous lethal and mutagenic properties. Fapy lesions are actively eliminated from DNA by repair glycosylases specific for oxidized purines and pyrimidines both in bacteria and eukaryotic cells. Bacterial enzymes include E.coli formamidopyrimidine-DNA-glycosylase (Fpg protein), endonuclease III (Nth protein) and endonuclease VIII (Nei protein).

Effect of Maengjong-Juk (Phyllostachys Pubescens) Extract Coated Rice Diet on Antioxidative System of C57BL/6 Mice Fed Atherogenic Diet (맹종죽(Phyllostachys Pubescens)추출물 코팅쌀이 Atherogenic 식이를 섭취한 C57BL/6 마우스의 항산화 시스템에 미치는 영향)

  • 김은영;이민자;송영옥;문갑순
    • Korean Journal of Community Nutrition
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    • v.9 no.4
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    • pp.536-544
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    • 2004
  • To evaluate the antioxidative effect of maengjong-juk (Phyllostachys pubescens) extract coated rice in vivo system, maengjong-juk extract coated rice diets were fed to C57BL/6 mice for 16 weeks. Plasma total antioxidative capacity, hepatic lipid peroxidation, protein oxidation, activities of antioxidative enzymes and total glutathione content were measured. Plasma total antioxidative capacity was elevated significantly in maengjong-juk extract diets supplemented group in a dose dependant manner. Hepatic TBARS contents were significantly decreased in maengjong-juk extract diets supplemented group compared to high cholesterol group. Maengjong-juk extract coated rice diets suppressed the protein oxidation significantly in liver. Activities of hepatic antioxidative enzymes such as total SOD, CuㆍZn-SOD, Mn-SOD, GSH-Px and catalase activities of maengjong-juk extract coated rice diets were significantly higher than those of high cholesterol diet. Total hepatic glutathione content was significantly increased by maengjong-juk extract coated rice diets administration. According to this study, numerous antioxidative materials and phytochemicals containing in maengjong-juk extracts appear to protect antioxidative systems in C57BL/6 mice fed bamboo extract coated rice diet. (Korean J Community Nutrition 9(4): 536∼544, 2004)

Structural Identification of Modified Amino Acids on the Interface between EPO and Its Receptor from EPO BRP, Human Recombinant Erythropoietin by LC/MS Analysis

  • Song, Kwang-Eun;Byeon, Jaehee;Moon, Dae-Bong;Kim, Hyong-Ha;Choi, Yoo-Joo;Suh, Jung-Keun
    • Molecules and Cells
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    • v.37 no.11
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    • pp.819-826
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    • 2014
  • Protein modifications of recombinant pharmaceuticals have been observed both in vitro and in vivo. These modifications may result in lower efficacy, as well as bioavailability changes and antigenicity among the protein pharmaceuticals. Therefore, the contents of modification should be monitored for the quality and efficacy of protein pharmaceuticals. The interface of EPO and its receptor was visualized, and potential amino acids interacting on the interface were also listed. Two different types of modifications on the interface were identified in the preparation of rHu-EPO BRP. A UPLC/Q-TOF MS method was used to evaluate the modification at those variants. The modification of the oxidized variant was localized on the Met54 and the deamidated variants were localized on the Asn47 and Asn147. The extent of oxidation at Met54 was 3.0% and those of deamidation at Asn47 and Asn147 were 2.9% and 4.8%, respectively.

Application of an Antimicrobial Protein Film in Beef Patties Packaging

  • Lee, Ji-Hyun;Song, Kyung Bin
    • Food Science of Animal Resources
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    • v.35 no.5
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    • pp.611-614
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    • 2015
  • This study was performed to apply a protein film containing a natural antimicrobial compound to meat packaging and determine quality change of meat during storage. Proteins obtained from the by-products of food processing have been utilized as biodegradable film sources. Porcine meat and bone meal (MBM) is obtained during meat processing, and proteins from the MBM can be extracted and used as a film base material. Previously, an antimicrobial MBM film containing coriander oil (CO) was prepared and its physical properties and antimicrobial activity were characterized. In this study, the antimicrobial MBM-CO film was applied to beef patties packaging, and the microbial population and the degree of lipid oxidation were determined during storage at 4℃ for 15 d. The population of inoculated E. coli O157:H7 in the samples wrapped with the MBM-CO film was 6.78 log colony forming unit (CFU)/g after 15 d of storage, whereas the control had 8.05 Log CFU/g, thus reducing the microbial population by 1.29 Log CFU/g. In addition, retardation of lipid oxidation in the patties was observed during storage for the samples packaged by the MBM-CO film, compared with the control samples. These results suggest that the MBM-CO film can be useful for enhancing the quality of beef patties during storage.

Photoprotective Effect of Lotus (Nelumbo nucifera Gaertn.) Seed Tea against UVB Irradiation

  • Kim, Su-Yeon;Moon, Gap-Soon
    • Preventive Nutrition and Food Science
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    • v.20 no.3
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    • pp.162-168
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    • 2015
  • Lotus (Nelumbo nucifera Gaertn.) seed is widely used as a traditional medicine in countries of Asia. Among many functions of the lotus seed, one interesting activity is its skin protection from the sunlight and scar. In this study, we focused on the skin protective property of lotus seed tea against ultraviolet B (UVB) irradiation. Two groups of a hairless mouse model, water as control (water group) and lotus seed tea (LST group), were administrated a fluid drink water for six months. After 6 month of administration, UVB exposure was carried out to both groups for another 3 months. During and after the administration, the skin moisture content and the morphological and histopathological analyses through biopsy were carried out. Prior to UVB irradiation, no significant difference was discovered in the skin moisture content for the water group and LST group (P<0.05). However, drastic changes were observed after the UVB treatment. The LST group showed a clear evidence of skin protection compared to the control group (P<0.05). The moisture content, epidermal and horny layer thickness, and protein carbonyl values all revealed that the intake of the lotus seed tea enhanced protection against UVB exposure. As a result, the long-term intake of the lotus seed tea showed the effect of preventing loss of skin moisture, mitigating the formation of abnormal keratinocytes, and contributing to protein oxidation inhibition.