• BMB Reports
• /
• v.41 no.9
• /
• pp.635-639
• /
• 2008

Acrolein is a highly reactive by product of lipid peroxidation and individuals with neurodegenerative disorders have been shown to contain elevated concentrations of this molecule in the brain. In the present study, we examined the pattern of neurofilament-L (NF-L) modification elicited by acrolein. When NF-L was incubated with acrolein, protein aggregation occurred in a acrolein concentration-dependent manner. Exposure of NF-L to acrolein also led to the generation of protein carbonyl compounds. Through the addition of free radical scavengers we observed a significant decrease in acrolein-mediated NF-L aggregation. These results indicate that free radicals may be involved in the modification of NF-L by acrolein. In addition, dityrosine crosslink formation was observed in acrolein-mediated NF-L aggregates and these aggregates displayed thioflavin T reactivity, reminiscent of amyloid. This study suggests that acrolein-mediated NF-L aggregation might be closely related to oxidative reactions, thus these reactions may play a critical role in neuro-degenerative diseases.

• Bulletin of the Korean Chemical Society
• /
• v.29 no.9
• /
• pp.1732-1736
• /
• 2008

The endogenous dipeptides, carnosine and related compounds, are the naturally occurring dipeptides with multiple neuroprotective properties. We have examined the protective effects of carnosine, homocarnosine and anserine on the aggregation of neurofilament-L (NF-L) induced by neurotoxin, acrolein. When NF-L was incubated with acrolein in the presence of carnosine, homocarnosine or anserine, protein aggregation was inhibited in a concentration-dependent manner. These compounds inhibited the formation of protein carbonyl compounds and dityrosine in acrolein-mediated NF-L aggregates. The aggregates of NF-L displayed thioflavin T reactivity, reminiscent of amyloid. This thioflavin T reactivity was inhibited by carnosine and related compounds. This effect was associated with decreased formation of oxidatively modified proteins. Our results suggested that carnosine and related compounds might have protective effects to brain proteins under pathophysiological conditions leading to degenerative damage such as neurodegenerative disorders.

• Food Science of Animal Resources
• /
• v.43 no.2
• /
• pp.305-318
• /
• 2023

This study investigated the protein digestibility of chicken breast and thigh in an in vitro digestion model to determine the better protein sources for the elderly in terms of bioavailability. For this purpose, the biochemical traits of raw muscles and the structural properties of myofibrillar proteins were monitored. The thigh had higher pH, 10% trichloroacetic acid-soluble α-amino groups, and protein carbonyl content than the breast (p<0.05). In the proximate composition, the thigh had higher crude fat and lower crude protein content than the breast (p<0.05). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of myofibrillar proteins showed noticeable differences in the band intensities of tropomyosin α-chain and myosin light chain-3 between the thigh and breast. The intrinsic tryptophan fluorescence intensity of myosin was lower in the thigh than in the breast (p<0.05). Moreover, circular dichroism spectroscopy of myosin revealed that the thigh had higher α-helical and lower β-sheet structures than the breast (p<0.05). The cooked muscles were then chopped and digested in the elderly digestion model. The thigh had more α-amino groups than the breast after both gastric and gastrointestinal digestion (p<0.05). SDS-PAGE analysis of the gastric digesta showed that more bands remained in the digesta of the breast than that of the thigh. The content of proteins less than 3 kDa in the gastrointestinal digesta was also higher in the thigh than in the breast (p<0.05). These results reveal that chicken thigh with higher in vitro protein digestibility is a more appropriate protein source for the elderly than chicken breast.

• The Korean Journal of Pharmacology
• /
• v.29 no.2
• /
• pp.195-202
• /
• 1993

Oxidative modification of cellular proteins and lipids may play a role in the development of diabetic complications. Diabetic cardiomyopathy has been suggested to be caused by the intracellular $Ca^{2+}$ overload in the myocardium, which is partly due to the defect of calcium transport of the cardiac sarcoplasmic reticulum (SR). In the present study, the possible mechanism of the functional defect of cardiac SR in diabetic rats was studied. Both of the maximal $Ca^{2+}$ uptake and the affinity for $Ca^{2+}$ were decreased in the diabetic rat SR in comparison with the control. To investigate whether the functional defect of the cardiac SR in streptozotocin-induced diabetic rat is associated with the oxidative changes of cardiac SR proteins, the carbonyl group content and glycohemoglobin levels were determined. The increase in carbonyl group content of cardiac SR (2.30 nmols/mg protein, DM; 1.78, control) and in glycohemoglobin level $(13{\sim}17%,\;DM;\;3{\sim}5%,\;control)$ were observed in the diabetics. The extent of increase in calcium transport by phospholamban phosphorylation was greater in the diabetic cardiac SR membranes than that in the control. The phosphorylation levels of phospholamban, as determined by SDS-PAGE and autoradiography with $[{\gamma}^{32}P]ATP$, were increased in diabetic cardiac SR. These results suggest that the impaired cardiac SR function in diabetic rat could be a consequence of the less-phosphorylation of phospholamban in the basal state, which is partly due to the depleted norepinephrine stores in the heart. Furthermore, the oxidative damages in cardiac SR membranes might be one of the additional factors leading to the diabetic cardiomyopathy.

• Korean Journal of Community Nutrition
• /
• v.9 no.4
• /
• pp.536-544
• /
• 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)

• Preventive Nutrition and Food Science
• /
• v.20 no.3
• /
• pp.162-168
• /
• 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.

• Journal of the Korean Society of Tobacco Science
• /
• v.31 no.2
• /
• pp.75-84
• /
• 2009

The objective of this study was to investigate the effect of nitrogen compounds such as protein on the chemical composition and toxicity of cigarette mainstream smoke. BSA protein was treated into the tobacco leaf of original 2R4F cigarette at 1~4 % level. The studies were performed which included a bacterial mutagenicity assay and a mammalian cell cytotoxicity assay for total particulate matter(TPM), and glutathione(GSH) consumption assay for gas/vapor phase(GVP) and determination of smoke chemical constitute. Cigarettes treated with protein were observed dose-dependent increase in yield of volatiles, semi-volatiles and aromatic amines compared with control cigarette. However, carbonyl compounds such as acrolein was lower than that of control cigarette when calculated on an equal TPM basis. The cytotoxicity of TPM obtained from the protein-added cigarettes was not different from that of control cigarette. However, the mutagenicity of the TPM from protein-treated cigarettes(1~4 %) was up to 10-27 % higher than that of control. On the other hand, toxicity of GVP from protein-treated cigarette(4 %) was significantly decreased compared with control cigarette. An overall assessment of our data suggests that nitrogen compounds such as protein should be important for the chemical composition and biological activity of cigarette mainstream smoke.

• Food Science of Animal Resources
• /
• v.39 no.5
• /
• pp.768-779
• /
• 2019

This study was performed to assess the comparison of the effects amongst butylated hydroxytoluene (BHT), clove extract (CE), and ascorbic acid (AA) as antioxidants on the oxidative stability and color values in fresh beef patties. The adding of BHT, AA, and CE to patties significantly restrained lipid oxidation, lowered hue angle as color value, and expanded redness and chroma values of fresh beef patties in comparison to the control (p<0.05). BHT and AA significantly led to impede the protein oxidation of patties by lowering carbonyl content (p<0.05). CE had no negative effect on protein oxidation. The antioxidant effects of BHT, AA, and CE were obviously manifested. Nonetheless, BHT, AA, and CE appeared to have insignificant difference of each other for lowering the protein oxidation at the end of storage. BHT and CE represented lowered lipid oxidation in comparison to AA. The antioxidant effects of BHT, AA, and CE on lipid oxidation were more marked than the effects on protein oxidation. Furthermore, CE as a natural antioxidant evinced the efficiency in oxidative stability and color stability in fresh beef patties. The study implied that CE could substitute the use of BHT and AA when making beef patties during storage.

• Proceedings of the Korean Society for Applied Microbiology Conference
• /
• 2002.10a
• /
• pp.18-25
• /
• 2002

The pikromycin biosynthetic system in Streptomyces venezuleae is unique for its ability to produce two groups of antibiotics that include the 12-membered ring macrolides methymycin and neomethymycin, and the 14-membered ring macrolides narbomycin and pikromycin. The metabolic pathway also contains two post polyketide-modification enzymes, a glycosyltransferase and P450 hydroxylase that have unusually broad substrate specificities. In order to explore further the substrate flexibility of these enzymes a series of hybrid polyketide synthases were constructed and their metabolic products characterized. The plasmid-based replacement of the multifunctional protein subunits of the pikromycin PKS in S. venezuelae by the corresponding subunits from heterologous modular PKSs resulted in recombinant strains that produce both 12- and 14-membered ring macrolactones with predicted structural alterations. In all cases, novel macrolactones were produced and further modified by the DesVII glycosyltransferase and PikC hydroxylase leading to biologically active macrolide structures. These results demonstrate that hybrid PKSs in S. venezuelae can produce a multiplicity of new macrolactones that are modified further by the highly flexible DesVII glycosyltransferase and PikC hydroxylase tailoring enzymes. This work demonstrates the unique capacity of the S. venezuelae pikromycin pathway to expand the toolbox of combinatorial biosynthesis and to accelerate the creation of novel biologically active natural products. The polyketide backbone of rifamycin B is assembled through successive condensation and ${\beta}$-carbonyl processing of the extender units by the modular rifamycin PKS. The eighth module, in the RifD protein, contains nonfunctional DH domain and functional KR domain, which specify the reduction of the ${\beta}$-carbonyl group resulting in the C-21 bydroxyl of rifamycin B. A four amino acid substitution and one amino acid deletion were introduced in the putative NADPH binding motif in the proposed KR domain encoded by rifD. This strategy of mutation was based on the amino acid sequences of the corresponding motif of the KR domain of module 3 in the RifA protein, which is believed dysfunctional, so as to introduce a minimum alteration and retain the reading frame intact, yet ensure loss of function. The resulting strain produces linear polyketides, from tetraketide to octaketide, which are also produced by a rifD disrupted mutant as a consequence of premature termination of polyketide assembly. Much of the structural diversity within the polyketide superfamily of natural products is due to the ability of PKSs to vary the reduction level of every other alternate carbon atom in the backbone. Thus, the ability to introduce heterologous reductive segments such as ketoreductase (KR), dehydratase (DH), and enoylreductase (ER) into modules that naturally lack these activities would increase the power of the combinatorial biosynthetic toolbox. The dehydratase domain of module 7 of the rifamycin PKS, which is predicted to be nonfunctional in view of the sequence of the apparent active site, was replaced with its functional homolog from module 7 of rapamycin-producing polyketide synthase. The resulting mutant strain behaved like a rifC disrupted mutant, i.e., it accumulated the heptaketide intermediate and its precursors. This result points out a major difficulty we have encountered with all the Amycolatopsis mediterranei strain containing hybrid polyketide synthases: all the engineered strains prepared so far accumulate a plethora of products derived from the polyketide chain assembly intermediates as major products instead of just analogs of rifamycin B or its ansamycin precursors.

• Korean Journal of Veterinary Research
• /
• v.34 no.2
• /
• pp.249-258
• /
• 1994

This study was carried out to investigate the inhibitory effects of vitamin E on the oxidative damage of cellular lipids and proteins in free radical reaction induced by $FeCl_3$, and ascorbic acid. In this experiment, a vitamin E treated rat group was administered with 100mg/kg body weight of $dl-{\alpha}-tocophery$ 1 acetate and an untreated rat group was administered with the same volume of corn oil. And then assays of malondialdehyde and carbonyl group in total homogenate, mitochondrial and microsomal fraction of rat liver were carried out at the scheduled time. The results obtained from this study were summarized as follows; 1. Lipid peroxidation levels in vitamin E administered rat liver cells were significantly (p<0.05) decreased at the intervals between 1 hour and 4 hours in liver homogenate, at all times except for 1 hour point in mitochondrial fraction, and also at the intervals between 0.5 hour and 3 hours in microsomal fraction compared with those of the control rat liver cell. 2. Protein oxidation levels in vitamin E administered rat liver cell were also significantly (p<0.05) decreased at the intervals between 1.5 hours and 4 hours in liver homogenate, at over 4 hours in liver mitochondrial fraction, and at the intervals between 0.5 hour and 3 hours in liver microsomal fraction compared with those of the control rat liver cells.