• 한국식품영양과학회지
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• 제32권7호
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• pp.1046-1052
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• 2003

Viscoelastic behavior of oxidized starch gel, modified with sodium hypochlorite (NaOCl) and the adding effects of protein in oxidized starch gel was studied by dynamic viscoelastic measurement. The storage modulus(G′) of starch gel increased with the increase of starch concentration. They showed higher value when starch suspension was treated to 95$^{\circ}C$ rather than 85$^{\circ}C$. Consistency of starch gel was decreased over 1.0% active Cl/g starch when heated to 95$^{\circ}C$, which means that the swelling of starch granules increased with concentration of NaOCl and showed more sensitive against shear. As the extent of oxidation increased, starch granules were easily destroyed. Therefore, it is hard to separate between compartment of leached-out amylose and that of amylopectin, which means that the ability of gel formation was reduced. When oxidized starches were gelatinized in presence of soy protein and sodium caseinate, it was found that G′ decreased, and frequency dependence of G′ and G" increased with the increased degree of oxidation in starch. The reduce of starch-protein interaction was thought to be through the dissociation of the branched amylopectin, which playa leading role in protein interaction, with the oxidation of starch.

• 한국식품과학회지
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• 제31권1호
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• pp.62-67
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• 1999

과요오드산 산화 가용성전분 및 말토올리고당을 고구마 ${\beta}-amylase$, 밀 ${\beta}-amylase$, aldolase, bovine serum albumin, catalase, carboxypeptidase, ferritin, pronase와 반응시켜서 전기영동하였다. 이들 단백질은 전기영동상의 이동도가 달라지고, 단백질 밴드와 같은 위치에서 PAS 염색 밴드를 나타내어 당이 부가된 것으로 확인되었다. 당의 부가는 과요오드산 산화당의 알데히드기가 단백질 분자 표면 리신의 ${\varepsilon}-NH_2$기와 Schiff 염기를 형성하여 일어난다. 변형효소는 자외흡광곡선에 변화를 나타내지 않았다.

• 한국식품과학회지
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• 제31권2호
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• pp.482-487
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• 1999

과요오드산으로 산화시킨 당을 유리아미노산과 반응시켜서 ${\alpha}-NH_2$기와 펩티딜리신의 ${\varepsilon}-NH_2$기와 반응하여 결합한 것을 확인하였다. 그래서, 제조한 과요드산-산화당은 단백질 분자 표면의 리신의 ${\varepsilon}-NH_2$기와 Schiff 염기 반응으로 공유결합하여 당단백질을 만드는 것으로 볼 수 있다. 과요드산 산화당으로 변형한 고구마 ${\beta}$-아밀라아제는 C, H는 증가, N은 감소하였다. N말단의 ${\alpha}-NH_2$기는 70% (pentamer), 73% (monomer), ${\varepsilon}-NH_2$기는 33% (pentamer), 26% (monomer)가 산화당과 반응하였다. 페놀-황산법에 의한 총당 정량과 DNP 법으로 분석한 결과, $IO_4$-산화말토헥사오스는 고구마 ${\beta}$-아밀라아제 1몰당 6몰이 결합된 것으로 나타났고, 고구마 ${\beta}$-아밀라아제에 결합된 산화가용성 전분은 효소단백질 대비 13.2% (monomer), 13.5% (pentamer), 산화말토헥사오스는 9.7% (pentamer), 9.3% (monomer)로 나타났다.

• Bulletin of the Korean Chemical Society
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• 제25권5호
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• pp.625-628
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• 2004

Ceruloplasmin (CP), the blue oxidase present in all vertebrates, is the major copper-containing protein of plasma. It has been proposed that oxidation of L-3,4-dihydroxyphenylalanine (DOPA) may contribute to the pathogenesis of neurodegenerative disorders. The effect of the oxidized products of DOPA on the modification of human CP was investigated. When CP was incubated with the oxidized L-DOPA, the protein was induced to be aggregated and ferroxidase activity was decreased in a time-dependent manner. Radical scavengers and catalase significantly inhibited the oxidized DOPA-mediated CP aggregation. Copper chelatrors, Diethylenetriaminepenta acetic acid (DTPA) and Diethyldithiocarbamic acid (DDC), also inhibited the oxidative modification of CP. The results suggested that DOPA oxidation led to the formation of free radical and induced the CP aggregation.

• Bulletin of the Korean Chemical Society
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• 제26권8호
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• pp.1255-1259
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• 2005

Lewy bodies (LBs) are neuronal inclusions that are closely related to Parkinson's disease (PD). The filamentous component of LB from patients with PD contains biochemically altered $\alpha$-synuclein. We have investigated the effect of the oxidized products of catecholamines on the modification of $\alpha$-synuclein. When $\alpha$-synuclein was incubated with the oxidized 3,4-dihydroxyphenylalanine (L-DOPA) or dopamine, the protein was induced to be aggregated. The oxidized catecholamine-mediated $\alpha$-synuclein aggregation was enhanced by copper ion. Radical scavengers, azide and N-acetyl cysteine significantly prevented the oxidized catecholamine-mediated $\alpha$-synuclein aggregation. The results suggest that free radical may play a role in $\alpha$-synuclein aggregation. Exposure of $\alpha$-synuclein to the oxidized products of catecholamines led to the formation of dityrosine. Antioxidant dipeptides carnosine, homocarnosine and anserine significantly protected $\alpha$-synuclein from the aggregation induced by the oxidized products of catecholamines.

• Animal Bioscience
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• 제34권4호
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• pp.724-733
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• 2021

Objective: The objectives of this study were to investigate the direct antioxidative effect of 90 Kda heat shock protein (Hsp90) obtained from duck muscle. Methods: The interaction of Hsp90 with phospholipids and oxidized phospholipids was studied with surface plasmon resonance (SPR), and their further oxidation in the presence of Hsp90 was evaluated with thiobarbituric acid reactive substances (TBARS) assay. The scavenging effect on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis (3-ethylbenzthiazoline-6-sulfonic acid (ABTS) was measured, and the electron paramagnetic resonance (EPR) spectroscopy in combination with 5-tert-Butoxycarbonyl-5-methyl-1-pyrroline-N-oxide and 2-phenyl-4,4,5,5,-tetramethylimidazoline-1-oxyl-3-oxide (PTIO) was utilized to determine the abilities of Hsp90 in scavenging hydroxyl and PTIO radicals. Results: SPR showed Hsp90 could bind with both phospholipids and oxidized phospholipids, and prevent their further oxidation by the TBARS assay. The DPPH and ABTS scavenging activity increased with Hsp90 concentration, and could reach 27% and 20% respectively at the protein concentration of 50 μM. The EPR spectra demonstrated Hsp90 could directly scavenge ·OH and PTIO· radicals. Conclusion: This suggests that Hsp90, a natural antioxidant in meat, may play an important role in cellular defense against oxidative stress, and may have potential use in meat products.

• Mass Spectrometry Letters
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• 제3권1호
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• pp.10-14
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• 2012

Artificially oxidized cysteine residues in peroxiredoxin 6 (Prx6) were detected by electrospray interface capillary liquid chromatography-linear ion trap mass spectrometry after the preparation of two-dimensional gel electrophoresis (2D-GE). We used Prx6 as a model protein because it possesses only two cysteine residues at the 47th and 91st positions. The spot of Prx6 on 2D-GE undergoes a basic (isoelectric point, pI 6.6) to acidic (pI 6.2) shift by exposure to peroxide due to selective overoxidation of the active-site cysteine Cys-47 but not of Cys-91. However, we detected a tryptic peptide containing cysteine sulfonic acid at the 47th position from the basic spot and a peptide containing both oxidized Cys-47 and oxidized Cys-91 from the acidic spot of Prx6 after the separation by 2D-GE. We prepared two types of oxidized Prx6s: carrying oxidized Cys-47 (single oxidized Prx6), and other carrying both oxidized Cys-47 and Cys-91 (double oxidized Prx6). Using these oxidized Prx6s, the single oxidized Prx6 and double oxidized Prx6 migrated to pIs at 6.2 and 5.9, respectively. These results suggest that oxidized Cys-47 from the basic spot and oxidized Cys-91 from the acidic spot are generated by artificial oxidation during sample handling processes after isoelectric focusing of 2D-GE. Therefore, it is important to make sure of the origin of cysteine oxidation, if it is physiological or artificial, when an oxidized cysteine residue(s) is identified.

• 한국식품과학회지
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• 제30권1호
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• pp.42-48
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• 1998

찰옥수수 전분을 차아염소산 나트륨$(0{\sim}60{\;}mg/s{\;}starch)$과 반응시켜 제조한 찰옥수수 산화전분의 이화학적 특성 및 유화 안정성에 미치는 영향에 대하여 연구하였다. 찰옥수수 산화전분의 일반성분 중 조지방질 및 조단백질 함량은 차아염소산 나트륨 처리량의 증가에 따라 감소하여 조단백질 함량과 백색도와 부의 상관관계$(R^2=0.9847)$를 나타내었고 조회분 함량은 증가하여 염소 함량과정의 상관관계$(R^2=0.9693)$를 나타내었다. 산화전분의 카르복시기 함량은 활성염소 첨가 농도에 비례하여 증가하였다. 호화액의 점도는 차아염소산 나트륨 처리량에 따라 현저히 감소하였고, 용해도와 팽윤력은 산화도가 높을 수록 증가하었으며, 광투과도는 치환도가 증가할 수록 낮은 온도에서 높은 투과도를 나타내어 화화개시온도가 약 $15^{\circ}C$낮아졌고, 호화액의 투명도 또한 개선되었다. 물결합능력은 치환도가 증가할 수록 생성된 카르복시기로 인하여 감소하였다. 찰옥수수 전분의 입자는 다각형과 원형의 혼합물로 크기는 $3.7{\sim}20\;{\mu}m$였으며, 차아염소산 나트륨 처리량이 증가할 수록 전분 표면이 거칠어졌다. 찰옥수수 산화전분과 옥배유를 균질화하여 저장하는 동안 유화액은 산화전분의 치환도가 높을 수록 전분의 농도가 증가할 수록 유화 안정성이 증가하였다.

• BMB Reports
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• 제37권3호
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• pp.325-329
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• 2004

Oxidation of catecholamines may contribute to the pathogenesis of Parkinson's disease (PD). The effect of the oxidized products of catecholamines on the modification of Cu,Zn-superoxide dismutase (SOD) was investigated. When Cu,Zn-SOD was incubated with the oxidized 3,4-dihydroxyphenylalanine (DOPA) or dopamine, the protein was induced to be aggregated. The deoxyribose assay showed that hydroxyl radicals were generated during the oxidation of catecholamines in the presence of copper ion. Radical scavengers, azide, N-acetylcysteine, and catalase inhibited the oxidized catecholamine-mediated Cu,Zn-SOD aggregation. Therefore, the results indicate that free radicals may play a role in the aggregation of Cu,Zn-SOD. When Cu,Zn-SOD that had been exposed to catecholamines was subsequently analyzed by an amino acid analysis, the glycine and histidine residues were particularly sensitive. These results suggest that the modification of Cu,Zn-SOD by oxidized catecholamines might induce the perturbation of cellular antioxidant systems and led to a deleterious cell condition.

• Molecules and Cells
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• 제25권3호
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• pp.452-456
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• 2008

The interactions between monocytes and extracellular matrix proteins have been implicated in atherosclerosis pathophysiology. In the present study we evaluated monocyte attachment and migration through oxidized and non-oxidized collagen IV. Monocyte attachment was tested on microwells coated with either native or oxidized collagen IV. Monocyte migration through collagen IV was examined on transwells. Monocytes derived from patients with diabetes mellitus showed an increased ability to attach and migrate through collagen IV as compared to those derived from healthy volunteers. Moreover, control monocytes attached to oxidized collagen at a higher degree, while they migrated through oxidized collagen at a lower degree, as compared to the native protein. Our results also showed the involvement of the alpha2 integrin subunit in the above phenomena suggesting a modified interaction between monocytes and collagen IV in diabetes mellitus.