• Title/Summary/Keyword: α-Amylase

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Nucleotide Sequence, Structural Investigation and Homology Modeling Studies of a Ca2+-independent α-amylase with Acidic pH-profile

  • Sajedi, Reza Hassan;Taghdir, Majid;Naderi-Manesh, Hossein;Khajeh, Khosro;Ranjbar, Bijan
    • BMB Reports
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    • v.40 no.3
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    • pp.315-324
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    • 2007
  • The novel $\alpha$-amylase purified from locally isolated strain, Bacillus sp. KR-8104, (KRA) (Enzyme Microb Technol; 2005; 36: 666-671) is active in a wide range of pH. The enzyme maximum activity is at pH 4.0 and it retains 90% of activity at pH 3.5. The irreversible thermoinactivation patterns of KRA and the enzyme activity are not changed in the presence and absence of $Ca^{2+}$ and EDTA. Therefore, KRA acts as a $Ca^{2+}$-independent enzyme. Based on circular dichroism (CD) data from thermal unfolding of the enzyme recorded at 222 nm, addition of $Ca^{2+}$ and EDTA similar to its irreversible thermoinactivation, does not influence the thermal denaturation of the enzyme and its Tm. The amino acid sequence of KRA was obtained from the nucleotide sequencing of PCR products of encoding gene. The deduced amino acid sequence of the enzyme revealed a very high sequence homology to Bacillus amyloliquefaciens (BAA) (85% identity, 90% similarity) and Bacillus licheniformis $\alpha$-amylases (BLA) (81% identity, 88% similarity). To elucidate and understand these characteristics of the $\alpha$-amylase, a model of 3D structure of KRA was constructed using the crystal structure of the mutant of BLA as the platform and refined with a molecular dynamics (MD) simulation program. Interestingly enough, there is only one amino acid substitution for KRA in comparison with BLA and BAA in the region involved in the calcium-binding sites. On the other hand, there are many amino acid differences between BLA and KRA at the interface of A and B domains and around the metal triad and active site area. These alterations could have a role in stabilizing the native structure of the loop in the active site cleft and maintenance and stabilization of the putative metal triad-binding site. The amino acid differences at the active site cleft and around the catalytic residues might affect their pKa values and consequently shift its pH profile. In addition, the intrinsic fluorescence intensity of the enzyme at 350 nm does not show considerable change at pH 3.5-7.0.

Protective effect of matcha green tea (Camellia sinensis) extract on high glucose- and oleic acid-induced hepatic inflammatory effect (고당 및 올레산으로 유도된 간세포에서의 염증반응에 대한 말차(Camellia sinensis) 추출물의 보호효과)

  • Kim, Jong Min;Lee, Uk;Kang, Jin Yong;Park, Seon Kyeong;Shin, Eun Jin;Moon, Jong Hyun;Kim, Min Ji;Lee, Hyo Lim;Kim, Gil Han;Jeong, Hye Rin;Park, Hyo Won;Kim, Jong Cheol;Heo, Ho Jin
    • Korean Journal of Food Science and Technology
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    • v.53 no.3
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    • pp.267-277
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    • 2021
  • To evaluate hepatoprotective effects, the antioxidant capacities of matcha green tea extract (Camellia sinenesis) were compared to those of green leaf tea and the anti-inflammatory activities in HepG2 cells were investigated. Evaluation of the total phenolic and total flavonoid content, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, and inhibitory effect on lipid peroxidation indicated that the aqueous extract of matcha green tea presented significant catechin content and antioxidant capacity compared to those of green leaf tea. In addition, the extract had considerable inhibitory effects on α-glucosidase, α-amylase, and advanced glycation end-products. The matcha green tea extract significantly increased cell viability and reduced reactive oxygen species in H2O2- and high-glucose-treated HepG2 cells. Furthermore, in response to oleic acid-induced HepG2 cell injury, treatment with matcha green tea aqueous extract inhibited lipid accumulation and regulated the expression of inflammatory proteins such as p-JNK, p-Akt, p-GSK-3β, caspase-3, COX-2, iNOS, and TNF-α. Matcha green tea could be used as a functional material to ameliorate hepatic lipid accumulation and inflammation.

Antimicrobial, Antioxidant, and Anti-diabetic Activities of Rodgersia podophylla (도깨비부채의 항균, 항산화 및 항당뇨 활성)

  • Pyo, Su-Jin;Lee, Yun-Jin;Kang, Deok-Gyeong;Son, Ho-Jun;Park, Gwang Hun;Park, Jong-Yi;Sohn, Ho-Yong
    • Journal of Life Science
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    • v.30 no.3
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    • pp.298-303
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    • 2020
  • This study aimed to investigate possible applications of Rodgersia podophylla in the food and cosmetic industry. Ethanol extracts of leaves (RP-L), branches (RP-B), and root (RP-R) were prepared, and their antimicrobial, antioxidant, and anti-diabetic activities were evaluated. The polyphenol content in the RP-R, RP-L, and RP-B extracts was 79.6, 30.4, and 16.9 mg/g, respectively. An antimicrobial activity assay showed that the RP-L and RP-R extracts exhibited strong growth inhibition of pathogenic and food spoilage Gram-positive bacteria. Furthermore, the RP-R extract inhibited the growth of the Gramnegative E. coli and P. vulgaris bacteria. All extracts showed strong scavenging activity for DPPH, ABTS, nitrite, and reducing power determined by A 700 nm. In particular, the RC50s of the RP-R extract for the DPPH anion and ABTS cation were 23.0-29.7 and 15.0-18.2 ㎍/ml, respectively, which are comparable to those of vitamin C (9.8 and 8.0 ㎍/ml, respectively). An activity assay of α-glucosidase and β-amylase suggested a high potential for the RP-R extract as an anti-diabetic agent. Its inhibition levels of α-glucosidase and β-amylase at 0.5 mg/ml were 6.9 and 48.5%, respectively. This is the first report of the antimicrobial and anti-diabetic activities of R. podophylla. Our results suggest that RP-L and RP-R extracts could be developed as novel cosmeceutical and functional food resources.

Analysis of Biological Activities and Functional Components in Different Parts of Asparagus (아스파라거스 부위별 유효성분 및 생리활성 분석)

  • Kwon, Soon-Bae;Kwon, Hye-Jeong;Jeon, Shin-Jae;Seo, Hyun-Taek;Kim, Hee-Yeon;Lim, Jae-Gil;Park, Ji-Seon
    • Korean Journal of Food Science and Technology
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    • v.52 no.1
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    • pp.67-74
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    • 2020
  • In this study, various constituents and biological activities of different parts of asparagus were analyzed and compared. The Ca content was high in the leaves, K was significantly high in the top 25 cm of the spear, and Fe and Na were significantly high in the roots. The ascorbic acid, rutin, total polyphenol, and total flavonoid contents were high in the leaves, and the asparagine and glutathione contents were significantly high in the top 25 cm of the spear and roots, respectively. The bottom 5 cm of the spear had the highest saponin content compared with all other parts. The DPPH and ABTS radical scavenging activities were the highest in the leaves. The bottom 5 cm of the spear had the highest α-amylase inhibitory activity, whereas the stem showed the highest anti-inflammatory activity. These results suggest that the usually inedible parts of asparagus may be highly valuable as high-quality functional components owing to their antioxidative and anti-inflammatory activities.

Antioxidant, Antibacterial and Anti-inflammatory Effects of Stachys sieboldii Extract (초석잠 추출물의 항산화, 항균 및 항염 활성)

  • Lee, Jeong Ho
    • Korean Journal of Plant Resources
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    • v.34 no.5
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    • pp.420-432
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    • 2021
  • This study was conducted to evaluate antioxidant, antibacterial, anti-inflammatory, and digestive enzyme activity in water extract (SAW) and 60% ethanol extract (SAE) from Stachys sieboldii. As the treatment concentration of each extract S. sieboldii extract increased, antibacterial and antioxidant activity increased. The total polyphenol and total flavonoid contents of SAW were 106.25 ± 0.94 mgGAE/g, 24.4 ± 0.24 mgQE/g and SAE were 124.61 ± 1.11 mgGAE/g, 45.2 ± 3.52 mgQE/g, respectively. The 400 ㎍/mL of SAW and SAE performed more than 53% protective effects against oxidative stress in HepG2 cell lines. All extracts were not showed cytotoxicity to RAW 264.7 cell line at 100 ㎍/mL. NO production was reduced to 44.3 ± 1.4% for SAW and 45.1 ± 1.0% for SAE at a concentration of 100 ㎍/mL. The production of inflammatory cytokines each TNF-α, IL-1β, and IL-6 was inhibited in a concentration-dependent. S. sieboldii extract did not showed Caco-2 cells cytotoxicity and inhibited NO production in concentration-dependent. As the concentration of the S. sieboldii extract increased of α-amylase and protease enzymes activity, which are digestive enzyme. As a result of the experiment, it is judged that it can be used as basic data for the development of health food using S. sieboldii.

Quality characteristics of kombucha made with saccharified rice solution (쌀당화액을 이용한 콤부차의 품질 특성)

  • Lee, Dae-Hyoung;Seo, Jae-Soon;Shin, Bok-Eum;Lee, Yong Seon;Cho, Chang Hui
    • Korean Journal of Food Science and Technology
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    • v.54 no.4
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    • pp.455-461
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    • 2022
  • In this study, kombucha was prepared using saccharified rice solution to assess this possible means of increasing rice consumption. Chucheong rice yielded the highest starch content (80.40±1.33%) when used to produce saccharified rice solution. The resultant saccharified rice solution showed the highest 10.42 °Brix at 90 min of saccharification. Chamdream rice yielded the highest acidity at 0.38%, and Kawaji No.1 yielded the lowest at 0.24%. Organic acid analysis on the 15th day of fermenting kombucha made with different rice varieties indicated an acetic acid content of 111.70±1.09 ppm in Chamdream, and 46.86±1.00 ppm in Dongjinchal. Comparison of enzymes used in saccharified rice kombucha fermentation revealed that α-amylase resulted in the highest acidity (1.06%), and β-amylase yielded the lowest acidity (0.58%). Kombucha with green tea yielded the highest acidity (1.09%), and kombucha with rooibos tea yielded the lowest (0.37%). Polyphenol analysis indicated that the amount of polyphenol increased the most (1,623.75 ppm to 3,989.00 ppm) on day 0 of fermentation with green tea. Organic acid analysis revealed that the acetic acid content of kombucha supplemented with green tea increased from 172.89 ppm on day 0 of fermentation to 2,649.11 ppm on day 15. Kombucha with 2.0% added alcohol had the highest acidity (1.32%), and kombucha with 0.5% alcohol had the lowest (0.97%). Taken together, these results confirm that it is possible to make kombucha using saccharified rice solutions.

Biological activities of extracts from Tongue fern (Pyrrosia lingua)

  • Akhmadjon, Sultanov;Hong, Shin Hyub;Lee, Eun-Ho;Park, Hye-Jin;Cho, Young-Je
    • Journal of Applied Biological Chemistry
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    • v.63 no.3
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    • pp.181-188
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    • 2020
  • In this study, Tongue fern (Pyrrosia lingua) plants that have been used traditionally as medicines. Their traditional medicinal uses, regions where indigenous people use the plants, parts of the plants used as medicines. This study was designed to assess the antioxidant and inhibition activities of extracts from P. lingua. In the P. lingua extracts was measured ethanol activity, 80.0% ethanol was high activity. The antioxidant activity was measured in 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-Azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), assays. DPPH and ABTS radical in this experiment, solid and phenolic of extract were tested, but only an average concentration of 100 ㎍/mL was used. However, the phenolic extract is shown phenolic activity reached a peak. Also, phenolic extracts ware reached peak water and ethanol extracts. As a result, using the phenolic extracts did other antioxidant assays such as DPPH, ABTS, protection factor, and thiobarbituric acid reactive substances at 50-200 ㎍/mL concentrations. The activity of elastase and collagenase, inhibiting their activities may retard skin aging. α-Glucosidase and α-amylase, inhibitors need to be explored for the benefit of postprandial hyperglycemia in diabetic patients. Activities of tyrosinase, hyaluronidase and xanthine oxidase inhibitors of these enzymes are increasingly important ingredients in cosmetics and medications to protect the skin against hyperpigmentation and skin aging. Inhibition effects were investigated using the P. lingua extracts at 50-200 ㎍/mL concentrations. The expression levels of enzyme inhibitions activities were decrease in dependent-concentrations manner when P. lingua extracts were treated.

Multi-Function of a New Bioactive Secondary Metabolite Derived from Endophytic Fungus Colletotrichum acutatum of Angelica sinensis

  • Ramy S. Yehia
    • Journal of Microbiology and Biotechnology
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    • v.33 no.6
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    • pp.806-822
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    • 2023
  • In the current study we assessed a new crystallized compound, 5-(1-hydroxybutyl)-4-methoxy-3-methyl-2H-pyran-2-one (C-HMMP), from the endophytic fungus Colletotrichum acutatum residing in the medicinal plant Angelica sinensis for its in vitro antimicrobial, antibiofilm, antioxidant, antimalarial, and anti-proliferative properties. The promising compound was identified as C-HMMP through antimicrobial-guided fraction. The structure of C-HMMP was unambiguously confirmed by 2D NMR and HIRS spectroscopic analysis. Antimicrobial property testing of C-HMMP showed it to be effective against a variety of pathogenic bacteria and fungi with MICs ranging from 3.9 to 31.25 ㎍/ml. The compound displayed excellent antibiofilm activity against C. albicans, S. aureus, and K. pneumonia. Furthermore, the antimalarial and radical scavenging activities of C-HMMP were clearly dosedependent, with IC50 values of 0.15 and 131.2 ㎍/ml. The anti-proliferative activity of C-HMMP against the HepG-2, HeLa, and MCF-7 cell lines in vitro was investigated by MTT assay, revealing notable anti-proliferative activity with IC50 values of 114.1, 90, and 133.6 ㎍/ml, respectively. Moreover, CHMMP successfully targets topoisomerase I and demonstrated beneficial anti-mutagenicity in the Ames test against the reactive carcinogenic mutagen, 2-aminofluorene (2-AF). Finally, the compound inhibited the activity of α-glucosidase and α-amylase with IC50 values of 144.7 and 118.6 ㎍/ml, respectively. To the best of our knowledge, the identified compound C-HMMP was obtained for the first time from C. acutatum of A. sinensis, and this study demonstrated that C-HMMP has relevant biological significance and could provide better therapeutic targets against disease.

Industrial potential of domestic Zanthoxylum piperitum and Zanthoxylum schinifolium: Protective effect of both extracts on high glucose-induced neurotoxicity (국내산 초피와 산초의 산업적 활용 가능성: 고당으로 유도된 뇌신경세포 독성에 대한 추출물의 보호 효과)

  • Han, Hye Ju;Park, Seon Kyeong;Kim, Min Ji;An, Jun Woo;Lee, Se Jin;Kang, Jin Yong;Kim, Jong Min;Heo, Ho Jin
    • Korean Journal of Food Science and Technology
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    • v.52 no.3
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    • pp.274-283
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    • 2020
  • This study focused on the in vitro investigation of antioxidant and anti-diabetic activities, along with neuroprotection against high glucose-induced cytotoxicity, in order to evaluate the physiological effects of Zanthoxylum piperitum and Zanthoxylum schinifolium. The highest total phenolic content was measured in the 40% ethanolic extracts of Zanthoxylum piperitum (EZP) and Zanthoxylum schinifolium (EZS). The in vitro EZP antioxidant activity showed a relatively higher ABTS/DPPH radical scavenging activity and malondialdehyde inhibitory effect than that of EZS. The EZP inhibited carbohydrate hydrolysis (α-glucosidase and α-amylase) more efficiently than EZS in anti-diabetic tests. However, EZS showed a more efficient inhibition of advanced glycation end-products formation than EZP. In addition, both EZP and EZS effectively protected human-derived neuronal cells from high glucose-induced cytotoxicity. Finally, the physiological compounds were analyzed using UPLC IMS-QTOF/MSE, and the main EZP (quercetin-3-O-glucoside and 3-caffeoylquinic acid) and EZS (5-caffeoylquinic acid) compounds were identified as phenolic compounds.

Isolation and Characterization of Microbial Strains with Hydrolytic Enzyme Profile from Clay Minerals

  • Lee, Sulhee;Cho, Eui-Sang;Nam, Young-Do;Park, So-Lim;Lim, Seong-Il;Seo, Dong-Ho;Kim, Jae-Hwan;Seo, Myung-Ji
    • Microbiology and Biotechnology Letters
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    • v.48 no.1
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    • pp.64-71
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    • 2020
  • A total of 262 bacterial strains were isolated from clay minerals, bentonite and zeolite, in Gyeongsangbukdo, Republic of Korea, and their hydrolytic enzyme activities were analyzed. Most of the isolated strains belonged to Micrococcales and Bacillales order. Of strains, 96 strains produced α-amylase activity, 42 strains showed cellulase activity, 111 strains had pectinase activity, and 70 strains showed protease activity. Among them, 177 isolates exhibited one or more of the hydrolytic enzyme activities and in particular Bacillus cereus MBLB1321, B. albus MBLB1326 and KIGAM017, B. mobilis MBLB1328, MBLB1329 and MBLB1330 showed all of the enzyme activities. These results demonstrate the diversity of functional Bacillus species in clay minerals as vital sources for the discovery of industrially valuable hydrolytic enzymes, which have a great commercial prospect in various bio-industrial applications.