• Journal of Oral Medicine and Pain
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• v.33 no.1
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• pp.1-8
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• 2008

It is well known that many antimicrobial proteins in saliva interact with each other. The purpose of the present study was to investigate the interactions of lysozyme with peroxidase in the aspects of enzymatic activity in vitro. The interactions of lysozyme with peroxidase were examined by incubating hen egg-white lysozyme(HEWL) with bovine lactoperoxidase(bLP). The influence of peroxidase system on lysozyme was examined by subsequent addition of potassium thiocyanate and hydrogen peroxide. Lysozyme activity was determined by turbidity measurement of a Micrococcus lysodeikticus substrate suspension. Peroxidase activity was determined with an NbsSCN assay. The Wilcoxon signed rank test was used to analyze the changes of enzymatic activities compared with their controls. bLP at physiological concentrations enhanced the enzymatic activity of HEWL(P < 0.05) and its effect was dependent on the concentration of peroxidase. However, HEWL did not affect the enzymatic activity of bLP. Thiocyanate did not affect the enzymatic activity of HEWL, either. The addition of potassium thiocyanate and hydrogen peroxide did not lead to additional enhancement of the enzymatic activity of HEWL. The changes of hydrogen peroxide concentration in the peroxidase system did not affect the enzymatic activity of HEWL. Collectively, despite an in vitro nature of our study, the results of the present study provide valuable information on the interactions of lysozyme and peroxidase in the aspects of enzymatic activity in oral health care products and possibly in the oral cavity.

• Fisheries and Aquatic Sciences
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• v.11 no.2
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• pp.71-75
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• 2008

The shell of Reeve's turtle has been used as a traditional folk medicine in Korea. We produced a hot water extract from Reeve's turtle shell according to the traditional medical practice. To release bioactive peptides, the hot water extract was enzymatically hydrolyzed with various proteases, and the free radical scavenging activity of the hydrolysate was investigated against 1,1-diphenyl-2-picryl-hydrazyl (DPPH), hydroxyl and peroxyl radicals. The free radical scavenging activity of the enzymatic hydrolysates varied from 1 to 79% depending on the enzymes, free radical species, and concentration. The $EC_{50}$ values demonstrated that the enzymatic hydrolysates of hot water extract from the shell of Reeve's turtle are potential antioxidants.

• ALGAE
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• v.18 no.1
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• pp.71-81
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• 2003

• Journal of Korean Medicine for Obesity Research
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• v.21 no.1
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• pp.1-9
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• 2021

Objectives: The enzymatic hydrolysis is one of the processing methods that improve its effectiveness on medicinal herbs. In this research, changes in ingredients and activity by enzymatic hydrolysis were studied. Methods: For this study, a carbohydrate hydrolase such as viscozyme, which converts glycosides to aglycone, was applied to induce constituent changes in Sophora japonica Linne, Houttuynia cordata Thunberg and Leonurus japonicus Houttuyn. Changes in antioxidant activity were measured using the 1,1-diphenyl-2-picrylhydrazl (DPPH) method, and changes in ingredients were analyzed by high performance liquid chromatography. Results: As a result of enzymatic hydrolysis, the content of quercetin was increased from 1.26 mg/g to 29.66 mg/g in Sophora japonica Linne, from 0 mg/g to 0.66 mg/g in Houttuynia cordata Thunberg and from 0.43 mg/g to 0.71 mg/g in Leonurus japonicus Houttuyn. As a result of the antioxidant experimentation, the IC₅₀ of Sophora japonica Linne decreased from 5 ug/ml (MeOH extract) and 9.1 ug/ml (EtOAc fraction) to 3.0 ug/ml, Houttuynia cordata Thunberg decreased from 15.6 ug/ml (MeOH extract) and 13.6 ug/ml (EtOAc fraction) to 11.2 ug/ml, and Leonurus japonicus Houttuyn decreased from 14.4 ug/ml (MeOH extract) and 12.6 ug/ml (EtOAc fraction) to 10.2 ug/ml. Conclusion: In conclusion, it was confirmed that glycoside rutin contained in the three medicinal herbs was changed to quercetin which is the aglycone, by the enzymatic hydrolysis using viscozyme. In terms of antioxidant activity, Sophora japonica Linne showed a significant antioxidant activity value that closes to the control group butylated hydroxyanisole. Houttuynia cordata Thunberg and Leonurus japonicus Houttuyn showed a minor increase in antioxidant activity.

• Preventive Nutrition and Food Science
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• v.13 no.3
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• pp.166-175
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• 2008

In this study, we focused on natural water-soluble antioxidants from the Jeju benthic diatoms, Achnanthes longipes, Navicula sp. and Amphora coffeaeformis. They were prepared by enzymatic digestion using five carbohydrases (Viscozyme, Celluclast, AMG, Termamyl and Ultraflo) and five proteases (Protamex, Kojizyme, Neutrase, Flavourzyme and Alcalase) and their potential antioxidant activity was assessed. Among the enzymatic digests, Neutrase digest from A. coffeaeformis exhibited the highest effect in DPPH radical scavenging. Flavourzyme (48.7%), Viscozyme (47.4%) and Celluclast (45.7%) digests from Navicula sp. exhibited higher $O^{{\cdot}-}_2$ radical scavenging activity. Viscozyme digest from A. coffeaeformis (45.9%) possessed the highest effects in hydroxyl radical scavenging. Termamyl (89.3%) and Protamex (88.8%) digests from A. coffeaeformis had strong metal chelating activity. Lipid peroxidation was significantly inhibited in Termamyl and Kojizyme digests from A. longipes, AMG and Termamyl digests from Navicula sp. and Kojizyme digest from A. coffeaeformisi. These data suggest that enzymatic digests of the Jeju benthic diatoms might be valuable sources of antioxidant which can be applied in food and pharmaceutical industry.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.253-253
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• 2006

DNA has not been played the role as a biocatalyst in evolutionary history, although RNA and protein function as a biocatalyst. DNA double helix structure is believed to be impossible to form intricate active enzymatic sites. In addition, the chemical stability of DNA prevents the ability from self-modifying reactions. However, recent development of DNA engineering enables to create artificial enzymatic ability of DNA (deoxyribozyme) such as RNA cleavage and DNA modification. We investigated optimal conditions for enzymatic activity of DNA-Pt complex, and compared it with that of horse radish peroxidase. We report here that base sequence of DNA, pH and temperature affect the enzymatic activity of DNA-Pt complex.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.194-197
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• 2000

The color of textile-wastewater hindered spectrometric measurements of $H_2O_2$ and enzyme activity during enzymatic decoloring. By using ABTS, we developed a new method for measuring peroxidase activity and $H_2O_2$ concentration. The ratio of enzyme and $H_2O_2$ was optimized as 1:150 by investigating the effects of $H_2O_2$ on enzymatic decoloring. Pulse feeding of $H_2O_2$, upon depletion, significantly increased the decoloring of Congo Red.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.3
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• pp.269-277
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• 2006

This study prepared functional oyster hydrolysates using two-step enzymatic hydrolysis and investigated their functional properties. To prepare two-step enzymatic hydrolysates (TSEH), oysters were hydrolyzed using 1% Protamex (PR) at $40^{\circ}C$ and pH 6.0 for 1 hr before sequential treatment with one of the following enzymes for 1 hr: Alcalase (AL), Flavourzyme (FL), Neutrase (NE), pepsin (PE), and trypsin (TR). The PRAL, PRNE and PRTR hydrolysates had significantly greater angiotensin I converting enzyme (ACE) inhibitory activity than did PR and the other TSEHs. Only the antioxidant activity of the PRNE hydrolysate was significantly different (p<0.05), while none of the TSEHs had antimicrobial activity. The oyster hydrolysate prepared by sequential treatment with Protamex and Neutrase (PRNE) had the best ACE inhibitory activity and antioxidant activity, with $IC_{50}$ values of 0.40 and 0.94 mg/mL, respectively. The PRNE hydrolysate was processed through an ultrafiltration (UF) series with molecular weight cut-off (MWCO) membranes of 3, 5, 10, and 30 kDa, and the ACE inhibitory, antioxidant, and antimicrobial activities of the permeates were determined. The permeate through the 3-kDa MWCO membrane had greater ACE inhibitory activity and antioxidant activity than did the other PRNE permeates, with $IC_{50}$ values of 0.11 and 0.40 mg/mL, respectively.

• Korean Journal of Veterinary Research
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• v.34 no.4
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• pp.781-785
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• 1994

Uridine diphosphate(UDP)-galactose-4-epimerase-less mutants of Salmonella pullorum were isolated after mutagenic treatment with ethidium bromide. When isolated gal E mutants of S. pullorum A2 and D1 were grown in the presence of galactose(0.1 W/V), they exhibited marked bacteriolysis in heart infusion broth. The mutant strains were further investigated the characteristics of enzymatic activities in the Leoloir galactose pathway. Isolated A2 and D1 strains were completely deficient in UDP-galactose-4-epimerase activity. And the activity of other enzymes involved in galactose metabolism were reduced significantly.

• ALGAE
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• v.18 no.4
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• pp.341-347
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• 2003

The potential antioxidative activity of water-soluble enzymatic hydrolyzates from a kelp, Ecklonia cava was evaluated by free radical scavenging and lipid peroxidation assays. To prepare water-soluble hydrolyzates from E. cava the seaweed was enzymatically hydrolyzed by five carbohydrases (Viscozyme, Celluclast, AMG, Termamyl and Ultraflo) and five proteases (Protamex, Kojizyme, Neutrase, Flavourzyme and Alcalase). Among all the hydrolyzates, Celluclast hydrolyzate effectively scavenged free radicals released from DPPH (1,1-diphenyl-2- pricrylhydrazyl) and recorded around 73% scavenging activity at the concentration of 4 mg ${\cdot}ml^{-1}$. This hydrolyzate was thermally stable and DPPH radical scavenging activity remained 80% or higher at heating temperatures of 40 and 60$^{\circ}C$ up to 12 h and around 80% at 100$^{\circ}C$ up to 8 h. AMG and Ultraflo hydrolyzate inhibited the lipid peroxidation of fish oil as that of $\alpha$-tocopherol. These results suggested that an enzymatic extraction will be an effective way for the production of a potential antioxidant from seaweeds.