• Title/Summary/Keyword: ${\alpha}$-amylase activity

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A New Extremely Halophilic, Calcium-Independent and Surfactant-Resistant Alpha-Amylase from Alkalibacterium sp. SL3

  • Wang, Guozeng;Luo, Meng;Lin, Juan;Lin, Yun;Yan, Renxiang;Streit, Wolfgang R.;Ye, Xiuyun
    • Journal of Microbiology and Biotechnology
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    • v.29 no.5
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    • pp.765-775
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    • 2019
  • A new ${\alpha}$-amylase-encoding gene (amySL3) of glycoside hydrolase (GH) family 13 was identified in soda lake isolate Alkalibacterium sp. SL3. The deduced AmySL3 shares high identities (82-98%) with putative ${\alpha}$-amylases from the genus Alkalibacterium, but has low identities (<53%) with functionally characterized counterparts. amySL3 was successfully expressed in Escherichia coli, and the recombinant enzyme (rAmySL3) was purified to electrophoretic homogeneity. The optimal temperature and pH of the activity of the purified rAmySL3 were determined to be $45^{\circ}C$ and pH 7.5, respectively. rAmySL3 was found to be extremely halophilic, showing maximal enzyme activity at a nearly saturated concentration of NaCl. Its thermostability was greatly enhanced in the presence of 4 M NaCl, and it was highly stable in 5 M NaCl. Moreover, the enzyme did not require calcium ions for activity, and was strongly resistant to a range of surfactants and hydrophobic organic solvents. The major hydrolysis products of rAmySL3 from soluble starch were maltobiose and maltotriose. The high ratio of acidic amino acids and highly negative electrostatic potential surface might account for the halophilic nature of AmySL3. The extremely halophilic, calcium-independent, and surfactant-resistant properties make AmySL3 a promising candidate enzyme for both basic research and industrial applications.

Role of ghrelin in the pancreatic exocrine secretion via mitogen-activated protein kinase signaling in rats

  • Lee, Kyung-Hoon;Lee, Jae-Sung;Wang, Tao;Oh, Jin-Ju;Roh, Sanggun;Lee, Hong-Gu
    • Journal of Animal Science and Technology
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    • v.59 no.7
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    • pp.16.1-16.6
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    • 2017
  • Background: This study was performed to investigate the impact of exogenous ghrelin on the pancreatic ${\alpha}$-amylase outputs and responses of pancreatic proteins to ghrelin that may relate to pancreatic exocrine. Methods: Sprague-Dawley male rats (9 weeks old, $300{\pm}10g$) were injected with ghrelin via intraperitoneal (i.p.) infusion at dosage of 0, 0.1, 1.0 and $10.0{\mu}g/kg$ body weight (BW), respectively. The plasma ghrelin and cholecystokinin (CCK) level were determined using enzyme immunoassay kit; the mRNA expression of ghrelin receptor ($GHSR-1{\alpha}$) and growth hormone (GH) receptor were assessed by reverse transcription PCR; the expressions of pancreatic ${\alpha}$-amylase activity, extracellular-signal-regulated kinases (ERK), phosphorylated extracellular-signal-regulated kinases (pERK) and c-Jun N-terminal kinase (JNK) were evaluated by western blotting; moreover the responses of pancreatic proteins to ghrelin were analyzed using the two-dimensional gel electrophoresis system. Results: The exogenous ghrelin (1.0 and $10.0{\mu}g/kg\;BW$) elevated the level of plasma ghrelin (p < 0.05), and suppressed the expression of pancreatic ${\alpha}$-amylase at a dose of $10.0{\mu}g/kg\;BW$ (p < 0.05). No difference in the level of plasma CCK was observed, even though rats were exposed to any dose of exogenous ghrelin. In addition, a combination of western blot and proteomic analysis revealed exogenous ghrelin ($10.0{\mu}g/kg\;BW$) induced increasing the JNK and ERK expressions (p < 0.05) and four proteins such as Destrin, Anionic trypsin-1, Trypsinogen, and especially eukaryotic translation initiation factor 3 in rat pancreas. Conclusions: Taken together, exogenous ghrelin by i.p. infusion plays a role in the pancreatic exocrine secretion via mitogen-activated protein kinase signaling pathway.

Protective Effects of Ethanol Extract from Aster Yomena on Acute Pancreatitis (쑥부쟁이 에탄올 추출물의 급성췌장염 보호 효과)

  • Seo, Sang Wan
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.33 no.2
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    • pp.109-115
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    • 2019
  • Aster Yomena (AY) has been used in traditional medicine to treat diseases such as obesity, hyperlipidemia, atherosclerosis, diabetes and osteoarthritis. However, protective effect of AY on acute pancreatitis (AP) has not been reported. The present study examined the anti-inflammatory effects of an ethanol extract of AY on cerulein-induced AP. AP was induced in mice by intraperitoneally injecting cerulein ($50{\mu}g/kg$) hourly for 6 times. 70% ethanol extract of AY (0.1, 0.2, and 0.5 g/kg) was orally administered for 1 week before acute pancreatitis induction. The mouse was killed at 6 hours after the final cerulein injection. The pancreas and lung were rapidly removed for histological examination and myeloperoxidase (MPO) assay. Blood samples were taken to determine serum amylase and lipase activity. In addition real-time reverse transcription-polymerase chain reaction (RT-PCR) was also performed to investigate mRNA expression of proinflammatory cytokines such as $TNF-{\alpha}$. $IL-1{\beta}$, and IL-6. Administration of AY significantly ameliorated pancreatic weight to body weight ratio, histological damages and MPO activity during AP. In addition, AY inhibited the serum amylase and lipase activity during AP. Also, mRNA expression of $TNF-{\alpha}$, $IL-1{\beta}$ and IL-6 were inhibited by AY against AP. Our results revealed that pre-treatment of AY reduces the severity of cerulein-induced AP. Therefore, AY may have a protective effect drug against AP.

Characteristics of the Bacteriocin Produced from Streptococcus salivarius subsp. thermophilus (Streptococcus salivarius subsp. thermophilus가 생산하는 Bacteriocin의 특성)

  • 이장혁;장효일
    • Microbiology and Biotechnology Letters
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    • v.22 no.1
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    • pp.7-12
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    • 1994
  • One bacterial strain, that had made the largest inhibition zone at the antagonism assay and also that lost the inhibition activity by the protease treatment, was isolated from raw milk. That strain was identified as Streptococcus salivarius subsp. thermophilus. The specific growht rate of this strain was maximum at 45$\circ $C. However, at this temperature the strain produced no bacteriocin. The bacteriocin activity was quite stable even at high temperature. Moreover, the activity of the vacteriocin was sensitive to proteases. but not to $\alpha $-amylase, DNase I, or RNase.

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Enzyme Activities of the Fruit Body of Ramaria botrytis DGUM 29001

  • Lee, Tae-Hee;Han, Yeong-Hwan
    • Mycobiology
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    • v.29 no.3
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    • pp.173-175
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    • 2001
  • The fruit body of Ramaria botrytis DGUM 29001 was used to determine enzyme activities of fruit body. The specific activity of laccase was the highest(6.5 unit/mg$\cdot$protein) and that of $\alpha$-amylase and xylanase was relatively high. However, little or no enzyme activity of $\beta$-glucosidase, CMCase, exo-$\beta$-1,4-glucanase, chitinase, lipase and protease was found.

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Antioxidant and α-Glucosidase Inhibitory Effect of Tartary Buckwheat Extract Obtained by the Treatment of Different Solvents and Enzymes (용매 종류와 효소 처리에 따른 쓴 메밀 추출물의 항산화 활성 및 α-Glucosidase 저해 활성의 변화)

  • Kim, Ji-Eun;Joo, Sung-Il;Seo, Ji-Hyun;Lee, Sam-Pin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.8
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    • pp.989-995
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    • 2009
  • Extract yield of tartary buckwheat treated with water, 70% ethanol or methanol were about 13.6%, 7.0% and 6.6%, respectively. Extract yield was greatly increased by the treatment of $\alpha$-amylase indicating 95.1% yield. $RC_{50}$ value of DPPH radical scavenging activity with methanol and 70% ethanol extracts were 34.0 $\mu g$/mL, 40.5 $\mu g$/mL, respectively. The DPPH radical scavenging activity increased when it was treated with $\beta$-glucosidase and cellulase, showing $RC_{50}$ value of 24.7 $\mu g$/mL and 25.0 $\mu g$/mL, respectively. In ABTS radical scavenging activity, methanol extract (100 $\mu g$/mL) showed 30% inhibition. In DPPH or ABTS radical scavenging activities, the treatment of $\beta$-glucanase and $\alpha$-amylase shows the highest and the lowest activities, respectively. In $\alpha$-glucosidase inhibitory effect, 70% ethanol extract showed $RC_{50}$ value of 59.9 $\mu g$/mL, but water extract was not inhibitory effective. The $\alpha$-glucosidase inhibitory effect was the highest in multi enzyme treatment. Content of rutin and quercetin in methanol extract showed higher value with 4400.3 mg% and 71.9 mg%, respectively. The 70% ethanol extract of buckwheat contained rutin of 3459.8 mg% and quercetin of 56.9 mg%. In the treatment of $\beta$-glucanase, the rutin content of ethanol extract increased with 5057.4 mg% and multi-enzyme treatment resulted in the modification of rutin glycoside.

Anti-aging and Anti-diabetes Effects of Aconitum pesudo-laeve var. erectum Extracts (진범(Aconitum pesudo-laeve var. erectum) 추출물의 항노화 및 항당뇨 효과)

  • Kim, Jeung-Hoan;Lee, Soo-Yeon;Kwon, O-Jun;Park, Joo-Hoon;Lee, Jin-Young
    • Journal of Life Science
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    • v.23 no.5
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    • pp.616-621
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    • 2013
  • Aconitum pesudo-laeve var erectum has been known to possess anti-inflammatory activity and modulate the intestinal immune system. In addition, it has traditionally been used for the treatment of water retention in the body. In this study, the anti-aging and anti-diabetes effects of water and ethanol extracts from Aconitum pesudo-laeve var. erectum were investigated. The activities of each extract were measured by antioxidant tests such as DPPH and ABTS radical scavenging activity, antioxidant protection factor (PF), TBARs content, and ${\alpha}$-amylase and ${\alpha}$-glucosidase inhibition activity assay. DPPH radical scavenging activity was found in over 50% of water and ethanol extracts at $100{\mu}g/ml$, $50{\mu}g/ml$, respectively. The ABTS radical scavenging activity of ethanol extract was $99.8{\pm}0.1$% at $1,000{\mu}g/ml$ in water, which was highest among the ethanol extract concentrations. PFs measured with ${\beta}$-carotene-linoleate model systems were in the order of ethanol (1.49 PF at $1,000{\mu}g/ml$) > ethanol (1.40 PF at $500{\mu}g/ml$) > water (1.33 PF at $1,000{\mu}g/ml$) > water (1.27 PF at $500{\mu}g/ml$). TBARs content in ethanol extracts ($1,000{\mu}g/ml$) was $0.16{\pm}0.03{\mu}M$, which was lower than that of water extracts and other ethanol extract concentrations. The extracts also showed over 90% of ${\alpha}$-amylase inhibition and over 60% of ${\alpha}$-glucosidase inhibition ratio in water ($1,000{\mu}g/ml$) and ethanol extracts (100~$1,000{\mu}g/ml$). These results suggest that Aconitum pesudo-laeve var. erectum extracts could be used as a cosmetic source and preventive agent for aging and diabetes.

Alkaline $\alpha$-amylase Production from Bacillus megaterium

  • Jia, Shiru;Lim, Chae-kyu;Seo, Gwang-Yeob;Nam, Hyung-Gun
    • Journal of environmental and Sanitary engineering
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    • v.24 no.1
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    • pp.40-46
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    • 2009
  • The enzyme expressed from strain L-49 was 2.01 times higher than that of original strain. Strain L-49 can grow on culture plate with $50{\mu}g/mL$ ampicillin. The synthesis of $\alpha$-amylase was greatly suppressed when strain L-49 was grown on monosaccharide such as glucose and polysaccharide at the same time cell concentration was low. Amylase production was enhanced when the bacterium was grown on starch and dextrin. Among different nitrogen sources tried, yeast extract was found to be the best followed by panpeptone, peptone, meat extract, bean meal, and corn steep liquor. The average rate of enzyme production was enhanced for 3~4 times in fermentation time from 24h to 44h. The sugar uptake rate has also increased. Low oxygen supply rate enhanced the rate of strain propagation but depressed the enzyme production. Hence it is benefit to obtain high enzyme activity that agitation speed maintained not lower than 400r/min and aeration rate maintained greater than 1:1vvm.

Rest-activity circadian rhythm in hospitalized older adults with mild cognitive impairment in Korea and its relationship with salivary alpha amylase: an exploratory study (노인요양병원에 입원한 경도인지장애 노인의 휴식-활동 일주기 리듬에 관한 탐색적 연구: 타액 알파 아밀라제와의 관련성을 중심으로)

  • Minhee Suh;Jihye Choi
    • Journal of Korean Biological Nursing Science
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    • v.25 no.4
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    • pp.306-315
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    • 2023
  • Purpose: This study aimed to evaluate the rest-activity circadian rhythm (RAR) using data obtained from wearable actigraph devices in hospitalized older adults with mild cognitive impairment (MCI), and to investigate its relationship with salivary alpha amylase (sAA). Methods: This secondary data analysis used data from the Hospitalized Older Adults' Cognition and Physical Activity Study. Actigraph data for 3-4 days were analyzed for RAR. RAR indices such as interdaily stability (IS), intradaily variability (IV), activity level during the most active 10-hour period and during the most least active 5-hour period, and relative amplitude (RA) were calculated. Data on sAA collected in the morning and general characteristics, including body mass index (BMI), were analyzed. Results: Data from 92 hospitalized older adults with MCI were analyzed. The IS, IV, RA were 0.23, 0.73, 0.88, respectively. The average level of sAA was 77.02 U/mL, and a higher level of sAA was significantly associated with better IS and RA in the regression analysis, while age, BMI, and cognitive level were not. BMI showed positive correlations with IS and RA. Conclusion: RAR in the hospitalized older adults with MCI was attenuated, showing especially low IS, which implies they failed to maintain regular and repetitive 24-hour RAR. Increased sAA and BMI were associated with robust RAR. Nurses need to pay attention to maintain robust RAR in hospitalized older adults with MCI, and strategies should be developed to improve their RAR.