• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.3
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• pp.367-375
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• 1998

The physicochemical properties of the $\alpha$-amylase inhibitors from black bean and naked barley is Korea were investigated. Preincubation time for maximum inhibition was 30min and no activity change was seen after that time. Optimum pH of the $\alpha$-amylase inhibitors from the black bean and naked barley was pH 7.0 and the inhibitory activities were stable in the range of pH 6.0~8.0 in both phosphate and Tris-HCI buffer solutions. Both inhibitors maintained more than 50% of activity after incubation for 17 min at 7$0^{\circ}C$. The inhibitors from the black bean and naked barley maintained more than 50% of activities after treatment for 40 min and 30 min with pepsin, and 30 min and 50 min with trypsin, respectively. Both inhibitors functioned via a noncompetitive mechanism and were active against porcine pancreatic and human salivary $\alpha$-amylases. The activities of both inhibitors were linear for the ionic stength ranging from 0 to 0.9. The addition of 70 mM maltose to the reaction mixture caused a maximum increase in the relative activities of both inhibitors, but it did not affect the dissociation of the EI complex. The activities of both inhibitors were significantly enhanced by adding 1mM of K+ or Mg2+.

• Microbiology and Biotechnology Letters
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• v.13 no.3
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• pp.223-232
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• 1985

To find microorganisms of producing $\alpha$-amylase inhibitors, actinomycetes were isolated from soil samples that were collected at different locations in Korea and screened for enzyme inhibitory activity. A strain of these microbes had a high inhibitory activity and was identified as one of the genus Streptomyces by morphological, biochemical and physiological studies according to the methods of the International Streptomyces Project (ISP). The medium used consisted of 3 ％ corn starch, 0.2％ yeast extract and 0.8％ peptone (pH 7.0). When this strain was aerobically cultured in the medium on a rotary shaker, the highest inhibitory activity was obtained after four days. This inhibitor had inhibitory activities on various $\alpha$-amylases and glucoamylase, but not on $\beta$-amylase.

• BMB Reports
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• v.40 no.4
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• pp.494-500
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• 2007

The endophytic bruchid pest Callosobruchus maculatus causes severe damage to storage cowpea seeds, leading to economical losses. For this reason the use of $\alpha$-amylase inhibitors to interfere with the pest digestion process has been an interesting alternative to control bruchids. With this aim, $\alpha$-amylase inhibitors from baru seeds (Dipteryx alata) were isolated by affinity chromatographic procedures, causing enhanced inhibition of C. maculatus and Anthonomus grandis $\alpha$-amylases. To attempt further purification, this fraction was applied onto a reversed-phase HPLC column, generating four peaks with remarkable inhibition toward C. maculatus $\alpha$-amylases. SDS-PAGE and MALDI-ToF analysis identified major proteins of approximately 5.0, 11.0, 20.0 and 55 kDa that showed $\alpha$-amylase inhibition. Results of in vivo bioassays using artificial seeds containing 1.0% (w/w) of baru crude extract revealed 40% cowpea weevil larvae mortality. These results provide evidence that several $\alpha$-amylase inhibitors classes, with biotechnological potential, can be isolated from a single plant species.

• Food Science and Preservation
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• v.1 no.2
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• pp.117-124
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• 1994

To investigate characterization of the ${\alpha}$-amylase inhibitors from cereals and legumes produced in Korea, inhibitory activities against ${\alpha}$-amylase with the inhibitor from barley(Hordeum vulgare), wheat(Triticum aestivun), black bean(Glycine max), bean(Cajanus cajon) and pea(Pisum sativum) were measured. Among the samples tested, inhibitors from naked barley and black bean(sabong) which showed the highest inhibitor activities of cereals and legumes, respectively, were characterized according to treatment condition. The results obtained were summarized as follows. During the germination of naked barley and black bean, ${\alpha}$-amylase activities were gradually increased but inhibitory activities against ${\alpha}$-amylases were decreased. Both activities were gradually decreased when naked barley and black bean were stored. More than 50% of activities of the inhibitors from naked barley and black bean were remained at 100$^{\circ}C$ for 15 min and 20 min, respectively, indicating that the inhibitor from black bean was more stable to heat than that of barley.

• YAKHAK HOEJI
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• v.33 no.3
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• pp.175-182
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• 1989

To find ${\alpha}-amylase$ inhibitors produced by microorganisms from soil, a strain which had a strong inhibitory activity against bacterial ${\alpha}-amylase$ was isolated from the soil sample collected in Korea. The morphological and physiological characteristics of this strain on several media and its utilization of carbon sources showed that it was one of Streptomyces species according to the International Streptomyces Project method. The amylase inhibitor of this strain was purified by active carbon adsorption, silicagel column chromatography, SP-Sephadex C-25 column chromatography, adsorption on Amberlite XAD-2. The inhibitor was oligosaccharide which was composed of glucose. The inhibitor had inhibitory activity against other amylase such as salivary ${\alpha}-amylase$, pancreatic ${\alpha}-amylase$, fungal ${\alpha}-amylase$ and gluco-amylase.

• Archives of Pharmacal Research
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• v.8 no.2
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• pp.67-75
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• 1985

To find emylase inhibitors produced by microorganisms from soil, a strain which had a strong inhibitory activity against bacteria .alpha.-amylase was isolated from the soil smaple collected in Seoul. The morphological and physiological characteristics of this strain on several media and its utilization of carbon sources showed that it was one of Streptomyces specties according to the international Streptomyces Project method. The amylase inhibitor of this strain was purified by means of acetone precipitation, adsorption on Amberlite XAD-2, and column chromatography on Amberlite CG-50 and SP-Sephadex C-25. The inhibitor was stable at the pH range of 1-10 and at 100.deg.C for half an hour, and had inhibitory activities against other amylases such as salivary .alpha.-amylase, pancreatic .alpha.-amylase, fungal .alpha.-amylase and glucoamylase. The kinetic studies of the inhibitor showed that its inhibitory effect on starch hydrolysis by .alpha.-amylase was non-competitive.

• YAKHAK HOEJI
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• v.32 no.5
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• pp.304-307
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• 1988

394 strains of soil microorganism were isolated from the Korean soil samples. The isolated strains were shake-cultured in oat-meal medium. The filtrates of the cultures were screened for the production of ${\alpha}-amylase$ inhibitors. Five strains were identified to produce ${\alpha}-amylase$ inhibitors. And these strains were identified as Actinomycetes.

• Advances in Traditional Medicine
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• v.4 no.4
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• pp.227-234
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• 2004

An ${\alpha}-Amylase$ was purified to apparent homogeneity from germinating soybean seeds (Glycine max). Enzyme showed high specificity for starch. ${\alpha}-Amylase$ from soybean has optimum pH at 7.6 in the pH range 4.0-10.6. At this pH, the $K_m$ of starch was 2.63 mg/ml and the $V_{max}$ was equal to 52.6 mg/ml/min protein. Optimum temperature of the enzyme was found to be $55^{\circ}C,\;Q_{10}$ equal to 1.85 and energy of activation equal to 12 kcal/mol. Additives like, EDTA reduced the activity of ${\alpha}-amylase$ whereas PMSF enhanced the activity. ${\alpha}-Amylase$ was inhibited by several heavy metal ions.

• Food Science and Biotechnology
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• v.17 no.2
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• pp.302-307
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• 2008

Novel amylase inhibitors were synthesized via transglycosylation by Thermotoga maritima glucosidase (TMG). TMG hydrolyzes acarbose, acarviosine-glucose, and maltooligosaccharide by releasing $^{14}C$-labeled glucose from the reducing end of each molecule. When TMG was incubated with acarviosine-glucose (the donor) and glucose (the acceptor), two major transfer products, compounds 1 and 2, were formed via transglycosylation. The structures of the transfer products were determined using thin-layer chromatography (TLC), high-performance ion chromatography (HPIC), and $^{13}C$ nuclear magnetic resonance (NMR) spectroscopy. The results indicate that acarviosine was transferred to glucose at either C-6, to give a $\alpha-(1{\rightarrow}6$) glycosidic linkage, or at C-3, to produce an $\alpha-(1{\rightarrow}3$) glycosidic linkage. The transfer products showed a mixed-type inhibition against porcine pancreatic $\alpha$-amylase; therefore, they may be useful not only as inhibitors but also as acarbose transition-state analogs to study the mechanism of amylase inhibition.

• Korean Journal of Food Science and Technology
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• v.33 no.1
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• pp.117-121
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• 2001

White kidney bean, Phaseolus vulgaris, contains proteinaceous inhibitors of ${\alpha}-amylase$. Two inhibitors have been purified by conventional protein fractionation methods such as ethanol precipitation, ammonium sulfate fractionation, DEAE-Sephadex ion exchange chromatography and Sephadex G-100 gel chromatography. The inhibitors were purified as I-1 and I-2 based on their elution order from the DEAE-Sephadex column. The overall purification ratio were about 15.0 and 14.8 for I-1 and I-2, respectively. The molecular weights of purified ${\alpha}-amylase$ inhibitors were 50,000 and 45,000 determined by Sephadex G-100 gel filtration and SDS-polyacrylamide gel electrophoresis. They contain $17.6{\sim}17%$ of carbohydrate, $70{\sim}80%$ of protein. The carbohydrates were composed of glucose : xylose : mannose : N-acetylglucosamine (5 : 3 : 50 : 42).