• BMB Reports
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• 제32권6호
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• pp.599-604
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• 1999

A highly conserved amino acid, glutamic acid (Glu), present at position 152 in the catalytic domain of the human immunodeficiency virus type 1 (HIV-1) integrase (IN) protein has been known to be critical for enzymatic function since substitution of Glu 152 with other residues results in a complete loss of enzymatic activities. In order to better understand the role of Glu 152 as a conserved residue in enzymatic action, intragenic second site mutations have been introduced around residue 152 of a mutant IN (E152A), and their biochemical properties were analyzed in terms of enzymatic activities. Disintegration activities were found to be significantly restored in several second site mutant INs, while integration activities were only recovered weakly. However, endonucleolytic activities were not discovered in all the mutant INs. These findings indicate that the second site mutations can partially restore that catalytic structure of the active site disturbed by the E152A mutation and lead to the regaining of integration and disintegration activities. In addition, it is also suggested that endonucleolytic activity requires a more accurate structure of the catalytic site than that for the integration and disintegration activities.

• Journal of Pharmaceutical Investigation
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• 제27권2호
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• pp.99-108
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• 1997

To evaluate the feasibility of mucosal delivery of thyrotropin releasing hormone (TRH) through various mucosae, enzymatic degradation and stabilization of TRH in the nasal, rectal and duodenal extracts of rabbits were studied. TRH in the extracts was assayed by HPLC and its degradation was found to follow apparent first-order kinetics. The residual concentrations of TRH in the mucosal extracts of nasal, rectal and duodenal segments after 24 hr of incubation were found to be $65.1({\pm}1.1),\;19.7({\pm}2.7)$ and 0%, and in the serosal extracts, $65.6({\pm}5.5),\;75.2({\pm}1.1)$ and $68.7({\pm}1.4)%$, respectively. This result suggests that there is a significant difference in the activity of TRH-degrading enzymes among the sites of administration. The inhibition of TRH degradation in the mucosa extracts was kinetically investigated using various additives such as thimerosal, benzalkonium chloride, disodium edetate, ${\sigma}-phenanthroline$, dithiothreitol and dithioerythritol, and $IC_{50}$ values of inhibitors were calculated. The results obtained showed that thimerosal (0.5 mM) and benzalkonium chloride (0.141 mM) protected TRH from the enzymatic degradation in all the mucosa extracts more than 95% after 24 hr of incubation.

• Journal of Microbiology and Biotechnology
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• 제22권10호
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• pp.1381-1387
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• 2012

We applied enzymatic hydrolysis and tangential flow filtration (TFF) to purify a novel anticancer peptide from Mytilus coruscus (M. coruscus) and investigated its anticancer properties. To prepare the peptide, eight proteases were employed for enzymatic hydrolysis. Pepsin hydrolysates, which showed clearly superior cytotoxic activity on prostate cancer cells, were further purified using a flow filtration system using a TFF and consecutive chromatographic methods. Finally, a novel anticancer peptide was obtained, and the sequence was identified as Ala-Phe-Asn-Ile-His-Asn-Arg-Asn-Leu-Leu. The peptide from M. coruscus effectively induced cell death on prostate, breast and lung cancer cells but not on normal liver cells. This is the first report of an anticancer peptide derived from the hydrolysates of M. coruscus.

• Mycobiology
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• 제49권4호
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• pp.421-433
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• 2021

Morchella is a genus of fungi with the ability to concentrate Cd both in the fruit-body and mycelium. However, the molecular mechanisms conferring resistance to Cd stress in Morchella are unknown. Here, RNA-based transcriptomic sequencing was used to identify the genes and pathways involved in Cd tolerance in Morchella spongiola. 7444 differentially expressed genes (DEGs) were identified by cultivating M. spongiola in media containing 0.15, 0.90, or 1.50 mg/L Cd²⁺. The DEGs were divided into six sub-clusters based on their global expression profiles. GO enrichment analysis indicated that numerous DEGs were associated with catalytic activity, cell cycle control, and the ribosome. KEGG enrichment analysis showed that the main pathways under Cd stress were MAPK signaling, oxidative phosphorylation, pyruvate metabolism, and propanoate metabolism. In addition, several DEGs encoding ion transporters, enzymatic/non-enzymatic antioxidants, and transcription factors were identified. Based on these results, a preliminary gene regulatory network was firstly proposed to illustrate the molecular mechanisms of Cd detoxification in M. spongiola. These results provide valuable insights into the Cd tolerance mechanism of M. spongiola and constitute a robust foundation for further studies on detoxification mechanisms in macrofungi that could potentially lead to the development of new and improved fungal bioremediation strategies.

• 한국식품과학회지
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• 제23권1호
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• pp.93-97
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• 1991

호알칼리성 Bacillus sp. YC-335가 생산하는 CGTase의 효소학적 특성 및 작용반응을 살펴보았다. ${\alpha}-CD,\;{\beta}-CD$ 및 ${\gamma}-CD$로부터 glucosyl residues를 설탕으로 전이시키는 반응에 대한 효소의 최대 반응속도, Vmax 값은 각각 $16.13,\;21.8,\;9.8{\mu}moles glucose/min/mg\;protein$이었으며 Km 값은 각각 1.68, 0.33, 0.37 mM이었다. 효소의 전분 가수분해활성은 여러 당류에 의해 촉진되었으며 특히 전분 가수분해 산물인 maltose와 glucose에 의한 효과가 가장 좋았다. 이 효소는 ${\beta}CD$에 의해 효소의 전분 분해활성이 저해되었으며 비경쟁적 저해형식을 보였다. 또한 전분으로부터 효소작용에 의해 생성된 산물을 총당량법 및 HPLC 분석을 통해 조사한 결과 이 효소는 cyclization 작용 뿐만 아니라 transglycosylation 작용과 disproportionation 작용을 가지는 것으로 확인하였다.

• Food Science and Biotechnology
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• 제16권1호
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• pp.90-98
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• 2007

The antioxidant activities of water ($H_2O$) and ethanol (EtOH) extracts from hamcho (Salicornia herbacea L.) juice and cake prepared by enzymatic treatments were evaluated by in vitro assays against DPPH, superoxide, and hydroxyl radicals. Among the $H_2O$ and EtOH extracts from five different carbohydrases treated, the EtOH extract from viscozyme-treated hamcho cake had higher yield and phenolic content, and exhibited the strongest radical scavenging activity against DPPH ($IC_{50}=186.91\;{\mu}g/mL$), superoxide ($IC_{50}=87.54\;{\mu}g/mL$), and hydroxyl radicals ($IC_{50}=367.07\;{\mu}g/mL$). Antioxidant assay-guided fractionation and purification of the EtOH extract led to isolation and identification of five phenolic compounds, procatechuic, ferulic and caffeic acids, quercetin, and isorhamnetin. Most of these phenolic compounds exhibited considerable DPPH, superoxide, and hydroxyl radical scavenging activities, and in particular, caffeic and ferulic acids had stronger superoxide and hydroxyl radical scavenging activities than the well-known antioxidant radical scavenger, (+)-catechin (p<0.05). Quercetin and isorhamnetin were the primary compounds responsible for the strong antioxidant activity in the EtOH extract of the viscozyme-treated hamcho cake. Meanwhile, these five phenolic compounds were detected in the EtOH extract of the viscozyme-treated hamcho cake at the following levels (dry base of hamcho); procatechuic acid (1.54 mg%), caffeic acid (6.87 mg%), ferulic acid (8.45 mg%), quercetin (12.63 mg%), and isorhamnetin (6.65 mg%). However, three of these phenolic compounds (procatechuic, caffeic acid, and ferulic acids) were detectable in the $H_2O$ extract of viscozyme-treated hamcho juice. These results suggest that the EtOH extract of viscozyme-treated hamcho cake may be a potential source of natural antioxidants.

• 한국해양바이오학회지
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• 제10권2호
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• pp.62-72
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• 2018

An active ingredient with hyaluronidase (HAse) inhibitory effect is one of the anti-aging approaches in cosmeceuticals. Here, red sea cucumbers (RSCs), Stichopus japonicus, from Jeju Island were evaluated to examine their HAse inhibitory and antioxidant activity effect. In this study, RSCs were extracted by six enzymatic hydrolysis (Alcalase; Al, Trypsin; Try, Neutrase; Neu, Pepsin; Pep, Alpha-chymotrypsin; Chy and Protamex; Pro). Alcalase hydrolysate (AlH) showed the highest antioxidant capacities for both of oxygen radical absorbance capacity (ORAC) and trolox equivalent antioxidant capacity (TEAC) methods, compared to those of other hydrolysates, at $66.59{\pm}0.78{\mu}M\;TE/mg$ and $135.78{\pm}3.24{\mu}M\;TE/mg$, respectively. Furthermore, AlH performed the highest capacity of HAse inhibitory with $IC_{50}$ value of 3.21 mg/ml. Thus, RSCs hydrolyzed by Al were chosen to determine the cellular antioxidant activity and hyaluronic acid (HA) production effect on Human immortalized keratinocyte cell line (HaCaT). The results showed that AlH improved the cell viabilities and intracellular reactive oxygen species (ROS) induced by 2,2'-Azobis(2-amidinopropane) dihydrochloride (AAPH) were significantly decreased. In addition, AlH increased HA amount by regulating HYAL2 and HAS2 expressions in the HaCaT cells. Taken together, AlH of RSCs collected from Jeju Island showed HAse inhibitory and antioxidant activities against skin-aging which shows its potentials can be an optional natural bioactive ingredient for novel cosmeceuticals.

• 생명과학회지
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• 제22권5호
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• pp.627-633
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• 2012

본 연구에서는 해수로부터 난소화성 복합다당류를 분해하는 해양미생물 $Microbulbifer$ sp. AJ-3의 효소에 대한 기질 특이성을 분석하고 균주가 생산하는 효소를 이용하여 매생이의 효소분해산물을 조제하여 이에대한 생리활성을 분석하였다. 효소의 활성은 agar에 대한 상대적인 활성으로 나타내었는데 chitin 34.8%, fucoidan 36.8%로 비교적 낮은 활성을 보였고, starch 51.2%, agarose와 laminaran은 agar와 비슷한 수준인 115.6%, 103.1%의 활성을 나타내었다. 이 뿐만 아니라 alginic acid에 대해서는 agar의 2배가 넘는 239.3%의 활성을 나타내었다. 매생이 효소분해산물의 항산화능은 DPPH radical 소거능과 SOD 활성측정으로 분석하였는데 매생이 효소분해산물 2 mg/ml의 농도에서 DPPH 라디칼 소거능은 32%, SOD 활성은 93%로 나타났다. 매생이 효소분해산물의 아질산염 소거능은 pH 1.2에서 82%, pH 3.0에서 53%, pH 6.0에서 12%로 positive control인 비타민C와 유사한 활성을 보였다. 매생이 효소분해산물의 숙취해소 효능은 ADH 활성증진에 미치는 영향을 조사하였는데 효소분해산물 2 mg/ml 농도에서 30%의 증가된 알콜 분해능이 나타났다. 매생이 효소분해산물의 미백 효능에 대해서는 tyrosinase 저해능으로 분석하였으며 2 mg/ml에서 28%의 저해활성을 나타내었고 농도가 증가함에 따라 유의적으로 증가하는 경향을 나타내었다.

• Journal of Applied Biological Chemistry
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• 제48권2호
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• pp.89-92
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• 2005

The germination of Lactuca sativa seeds was significantly inhibited by the water extract of the fresh leaves of Pulsatilla koreana N. including abundant ranunculin. Germination inhibitory activity increased in a dose-dependantly. Protoanemonin, produced from ranunculin by enzymatic action during maceration process of leaves, was proved to be the active principle with inhibitory activity was above 90% at concentration of 1 mg/ml.

• BMB Reports
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• 제33권6호
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• pp.427-439
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• 2000

The activity of the phagocyte respiratory burst oxidase is regulated by complex and dynamic alterations in protein-protein interactions that result in the rapid assembly of an active multicomponent NADPH oxidase enzyme on the plasma membrane. While the enzymatic activity has been studied for the past 20 years, the past decade has seen remarkable progress in our understanding of the enzyme and its activation at the molecular level. This article describes the current state of knowledge, and proposes a model for the mechanism by which protein-protein interactions regulate enzyme activity in this system.