• Title/Summary/Keyword: ${\alpha}$-amino acids

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Effect of Germination Condition and Drying Methods on Physicochemical Properties of Sprouted Brown Rice (발아조건 및 건조방법이 발아현미의 이화학적 특성에 미치는 영향)

  • 김선림;손영구;손종록;허한순
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.46 no.3
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    • pp.221-228
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    • 2001
  • This study was carried out to investigate the effect of germination condition and drying temperature on growth and physicochemical properties of brown rice. Three brown rice seeds of Ilpumbyeo, Dasanbyeo and Heugjinjubyeo were stored at room temperature for six weeks to test the time-sequence germination viability. Relatively stable germination ratio was maintained until 2 weeks after storage. However, 3 weeks after storage, germination ratio of brown rice seeds started to decrease rapidly and their germination ratio was lower than 80%. For this reason, brown rice was recommended for seeding within 2 weeks after hulling. During the initial 5 days, germination ratio of 24 hours pre-soaking brown rice was higher about 2-3% than that of non-soaking brown rice. The $25^{\circ}C$ was considered as the most favorable temperature for brown rice germination, because of the high germination ratio and desirable coleoptile growth of the brown rice, and little seed rotting symptoms. The scanning electron micrographs showed the structural differences between hot-air dried and freeze dried germinated-brown rice kernel. In the freeze dried germinated-brown rice, seed coat (pericarp, tegmen and aleurone layer) was mechanically disrupted from the endosperm, and many cleavages were observed among starch storing cells and starch granules. The endosperm of freeze-dried brown rice kernels formed the sponge-like structures and showed the fragile traits. For this reason, hot-air drying is considered as more suitable method than freeze drying for germinated-brown rice. The crude protein and amylose contents were slightly changed, but there were no significant differences during the germination period. Crude fiber content was decreased, but crude Int and total amino acid contents were increased as seeding days increased. A rapid increase in $\alpha$-amylase activities of germinating brown rice was observed at S days after seeding, and $\alpha$-amylase activities were decreased from 8 days after seeding. Total free sugar contents were decreased during the germination period. There was continuous decline in the contents of sucrose and glucose until 8 days after seeding, but fructose and maltose content were gradually increased from the 5 days after seeding.

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Quality Characteristics of Fermented Soybean Products by Bacillus sp. Isolated from Traditional Soybean Paste (전통장류 유래 Bacillus sp.를 이용한 콩 발효물의 품질 특성)

  • Lee, Sun Young;Eom, Jeong Seon;Choi, Hye Sun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.5
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    • pp.756-762
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    • 2014
  • This study evaluated the quality characteristics of soybean fermented with several Bacillus sp., which were selected based on their high enzymatic and antimicrobial activities. Total aerobic bacterial counts of fermented soybeans with HJ5-2 ($3.00{\times}10^9CFU/mL$) were the highest among all strains. Lactic acid bacteria numbered $2.50{\times}10^2{\sim}7.30{\times}10^4CFU/mL$ in soybeans fermented with isolates. Amylase and protease activities of the RD7-7 sample were the highest among all strains. Reducing sugar and amino-type nitrogen contents of fermented soybeans with HJ18-4 (2.35%) and RD7-7 (227.96 mg%) were the highest. Total amino acid contents of the samples were 16.62~18.38%, and glutamic acid, aspartic acid, leucine, lysine, arginine were major amino acids. Oxalic acid (36.51~63.57 mg/100 g) and succinic acid (429.49~600.15 mg/100 g) were the predominant organic acid. These results provide useful information for development starter (single and complex) as well as for the production of high quality fermented soybean foods.

Peptide Synthesis with Polymer Bound Active Ester III. The Effect of Spacer Arm in Peptide Synthesis with 1-Phenyl-3-methyl-4-oximino pyrazole Resin (고분자에 결합된 활성 에스테르에 의한 펩티드합성 III. 1-페닐-3-메틸-4-옥시미노피라졸레진을 이용한 펩티드 합성에서 Spacer Arm의 효과)

  • Wang, Young;Lee, Yoon-Sik
    • Applied Chemistry for Engineering
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    • v.4 no.1
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    • pp.132-143
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    • 1993
  • Aminomethyl polystyrene resins were prepared either from chloromethyl-resin(Merrifield resin) or from direct amidoalkylation of polystyrene resin. Two kinds of aminomethlyl resin were lengthened with spacer arms via sequential coupling of five ${\varepsilon}$-aminocaproic acids(ACA) respectively. In case of the resin prepared from the Merrifield resin, the amounts of free amino group of the resin were reduced by 25~30% after each coupling of ACA. But the one from direct amidoalkylation showed 3~5% loss after each coupling of ACA. 4-Nitroso-5-aminopyrazole resin was made by reacting ACA spacer arm resin, which was made from direct amidoalkylated resin, with 5-phenyl-7-methylpyrazole [4,3-c][1,2,4]oxadiazin-3-one. Several polymeric active esters of N-blocked amino acids were prepared from the 4-nitroso-5-aminopyrazole bound resins. In anchoring step of the amino acid derivatives on the resin, no substantial effect of bulkiness was found. 4-Nitroso-5-aminopyrazole bound active ester resins were found to be very reactive in N-acylation, The resulting peptides were obtained with 90~95% yield and characterized by NMR and other physical methods.

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A Novel Ubiqutin C-terminal Hydrolase (UCH-9) from Chick Skeletal Muscle: Its Purification and Charaterization

  • U, Seong-Gyun;Baek, Seong-Hui;Sin, Dong-Hun;Kim, Hye-Seon;Yu, Yeong-Jun;Jo, Jung-Myeong;Gang, Man-Sik;Jeong, Jin-Ha
    • Animal cells and systems
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    • v.1 no.2
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    • pp.323-328
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    • 1997
  • We have previously shown that chick muscle extracts contained at least 10 different ubiquitin C-terminal hydrolases (UCHs). In the present studies, one of the enzymes, called UCH-9, was purified by conventional chromatographic procedures using $^{125}l$-labeled ubiquitin-${\alpha}$NH-MHISPPEPESEEEEE HYC (Ub-PESTc) as a substrate. The purified enzyme behaved as a 27-kDa protein under both denaturing and nondenaturing conditions, suggesting that it consists of a single polypeptide chain. It was maximally active at pHs between 7 and 8.5, but showed little or no activity at pH below 6 and above 10. Lice other UCHs, its activity was strongly inhibited by sulfhydryl blocking reagents, such as iodoacetamide, and by Ub-aldehyde. In addition to Ub-PESTc, UCH-9 hydrolyzed Ub-aNH-protein extensions, including Ub-${\alpha}NH$-carboxyl extension protein of 80 amino acids and Ubo-${\alpha}NH$-dihydrofolate reductase. However, this enzyme was not capable of generating free Ub from mono-Ub-${\varepsilon}NH$-protein conjugates and from branched poly-Ub chains that are ligated to proteins through ${\varepsilon}NH$-isopeptide bonds. This enzyme neither could hydrolyze poly-His-tagged di-Ub. These results suggest that UCH-9 may play an important role in production of free Ub and ribosomal proteins from their conjugates.

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Expression and Characterization of ${\alpha}$-Methylacyl CoA Racemase from Anisakis simplex Larvae

  • Kim, Bong-Jin;Kim, Sun-Mi;Cho, Min-Kyung;Yu, Hak-Sun;Lee, Yong-Seok;Cha, Hee-Jae;Ock, Mee-Sun
    • Parasites, Hosts and Diseases
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    • v.50 no.2
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    • pp.165-171
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    • 2012
  • Larval excretory-secretory products of Anisakis simplex are known to cause allergic reactions in humans. A cDNA library of A. simplex 3rd-stage larvae (L3) was immunoscreened with polyclonal rabbit serum raised against A. simplex L3 excretory-secretory products to identify an antigen that elicits the immune response. One cDNA clone, designated as ${\alpha}$-methylacyl CoA racemase (Amacr) contained a 1,412 bp cDNA transcript with a single open reading frame that encoded 418 amino acids. A. simplex Amacr showed a high degree of homology compared to Amacr orthologs from other species. Amacr mRNA was highly and constitutively expressed regardless of temperature (10-$40^{\circ}C$) and time (24-48 hr). Immunohistochemical analysis revealed that Amacr was expressed mainly in the ventriculus of A. simplex larvae. The Amacr protein produced in large quantities from the ventriculus is probably responsible for many functions in the development and growth of A. simplex larvae.

Production of Iron-Binding Peptides from Colostral Whey by Enzymatic Hydrolysis

  • Kim, Sang-Bum;Ku, Min-Jung;Cho, Won-Mo;Ki, Kwang-Seok;Kim, Hyeon-Shup;Nam, Myoung-Soo
    • Food Science of Animal Resources
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    • v.30 no.6
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    • pp.923-929
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    • 2010
  • Colostral whey prepared from colostrum (pooled from first six post-partum milkings) was heated for 10 min at $100^{\circ}C$ Heated colostral whey was incubated with 1% enzymes (protein equivalent basis) for 15, 30, 60, 90, and 120 min at $50^{\circ}C$. Papain, pepsin, trypsin, and alcalase produced different degrees of hydrolysis (DH), 10.66%, 12.42%, 10.83%, and 25.31%, respectively, at an incubation time of 120 min. The SDS-PAGE reveals that significant amounts of bovine serum albumin (BSA), ${\beta}$-lactoglobulin (${\beta}$-LG), and ${\alpha}$-lactalbumin (${\alpha}$-LA) survived papain digestion. In contrast, pepsin completely removed BSA but not ${\beta}$-LG present in heated colostral whey. Alcalase completely eliminated BSA, ${\beta}$-LG, and ${\alpha}$-LA. This differential hydrolysis was confirmed by reversed-phase HPLC analysis. Using ion-exchange chromatography, fraction-1 (F-1) was obtained from alcalase hydrolysate at a NaCl gradient concentration of 0.25 M. Reversed-phase HPLC chromatograms of alcalase F-1 showed numerous small peaks, which probably indicate that a variety of new peptides were produced. Iron content of alcalase F-1 was 28.94 ppm, which was the highest among all enzyme fractions, whereas iron content of colostral whey was 36.56 ppm. Main amino acids contained in alcalase F-1 were Thr (15.45%), Glu (14.12%), and Ser (10.39%). Therefore, alcalase can be used to generate good iron-binding peptides in heated colostral whey, and the resulting iron-binding peptides could be suitable as a value-added food ingredient for food supplements.

GTG as a Potential Translation Initiation Godon in Mitochondrial F1 ATPase $\alpha$-Subunit Gene(atpA) of Korean Ginseng (고려인삼의 $F_1$ ATPase $\alpha$-Subunit 유전자(atpA)의 구조적 특성)

  • Kim, Kab-Sig;Park, Ui-Sun;Choi, Kwan-Sam;Choi, Kwang-Tae
    • Journal of Ginseng Research
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    • v.19 no.2
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    • pp.127-133
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    • 1995
  • The complete open reading frame (ORF) of o-subunit of the $F_1$ ATP synthase (atPA) in Korean ginseng mitochondria was identified by the sequence similarity with atPA genes in other plant mitochondria. The sequence alignment showed that the common translation initiation codon, ATG, in plant genes was replaced with GTG valid codon in Korean ginseng. The atPA gene from GTG to TGA termination codon was 1524 nucleotides long, and the sequence homology of nucleotides and deduced amino acids revealed high values of 92~97%. A deletion event of 6 nucleotides was observed at the 1468th nucleotide from the GTG in Korean ginseng, in contrast to that at the 1450th in other plants such as pea, common bean, soybean, sugar beet, and radish. An unidentified open reading frame (on7) was observed upstream of atmA ORF. No other ATG as an initiation codon was detected in the region between off and atmA ORF in Korean ginseng, although a pyrimidine cluster "TTTTCTTTT" was located in this region as in Oenothera and maize genes. It could be supposed that GTG codon in atpA gene of Korean ginseng mitochondria would act as an initiation codon as in microbial genes.ial genes.

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Chemical Compositions and Antioxidant Activity of the Colored Rice Cultivars (유색미의 화학적성분 및 항산화활성)

  • Kim, Eun-Ok;Oh, Ji-Hae;Lee, Kee-Taek;Im, Jung-Gyo;Kim, Sung-Soo;Suh, Hak-Soo;Choi, Sang-Won
    • Food Science and Preservation
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    • v.15 no.1
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    • pp.118-124
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    • 2008
  • The chemical compositions and antioxidant activities of four different colored rice cultivars (white-colored rice: WCR, brown-colored rice: BCR, brown-colored waxy rice: BCWR, black-colored rice: BKCR) were investigated to evaluate the quality characteristics of the new brown rice cultivars. There was no significant differences in chemical compositions amongst the four rice cultivars, although WCR had higher amount of carbohydrate than did the other rice cultivars. 'The major fatty acids in the four rice cultivars were linoleic, oleic and palmitic acids, which accounted for about 96% of total fatty acids. Of note, higher amounts of saturated fatty acids (24.8%) and lower amount of unsaturated fatty acids (75.2%) were observed in BKCR than in the other rice cultivars. Two brown-colored rice cultivars, BCR and BCWR, possessed higher amounts of linoleic acid (40.8% and 42.1%, respectively) than did the other cultivars. The highest level of ${\alpha}$-tocopherol was found in WCR (51.3mg%), followed by BKCR (38.6mg%), BCWR (37.2 mg%), and BCR (34.5mg%). Free amino acid analysis showed that aspartic and glutamic acids were major amino acids of all cultivars, whereas phenylalanine, lysine, and histidine were minor. Particularly, relatively higher contents of aspartic and glutamic acids were found in BKCR, while relatively higher levels of alanine and ${\gamma}$-aminobutyric acid (GABA) were observed in BCR and BCWR. Also, BKCR had the highest phenolic content and antioxidant activity of any cultivar, followed by the two brown-colored rice cultivars and WCR. These results suggested that the new brown rice cultivars may possess quality characteristics intermediate between those of WCR and BCR.

A Role for Leu247 Residue within Transmembrane Domain 2 in Ginsenoside-Mediated α7 Nicotinic Acetylcholine Receptor Regulation

  • Lee, Byung-Hwan;Choi, Sun-Hye;Pyo, Mi Kyung;Shin, Tae-Joon;Hwang, Sung-Hee;Kim, Bo-Ra;Lee, Sang-MoK;Lee, Jun-Ho;Lee, Joon-Hee;Lee, Hui Sun;Choe, Han;Han, Kyou-Hoon;Kim, Hyoung-Chun;Rhim, Hyewhon;Yong, Joon-Hwan;Nah, Seung-Yeol
    • Molecules and Cells
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    • v.27 no.5
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    • pp.591-599
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    • 2009
  • Nicotinic acetylcholine receptors (nAChRs) play important roles in nervous system functions and are involved in a variety of diseases. We previously demonstrated that ginsenosides, the active ingredients of Panax ginseng, inhibit subsets of nAChR channel currents, but not ${\alpha}7$, expressed in Xenopus laevis oocytes. Mutation of the highly conserved Leu247 to Thr247 in the transmembrane domain 2 (TM2) channel pore region of ${\alpha}7$ nAChR induces alterations in channel gating properties and converts ${\alpha}7$ nAChR antagonists into agonists. In the present study, we assessed how point mutations in the Leu247 residue leading to various amino acids affect 20(S)-ginsenoside $Rg_3$ ($Rg_3$) activity against the ${\alpha}7$ nAChR. Mutation of L247 to L247A, L247D, L247E, L247I, L247S, and L247T, but not L247K, rendered mutant receptors sensitive to $Rg_3$. We further characterized $Rg_3$ regulation of L247T receptors. We found that $Rg_3$ inhibition of mutant ${\alpha}7$ nAChR channel currents was reversible and concentration-dependent. $Rg_3$ inhibition was strongly voltage-dependent and noncompetitive manner. These results indicate that the interaction between $Rg_3$ and mutant receptors might differ from its interaction with the wild-type receptor. To identify differences in $Rg_3$ interactions between wild-type and L247T receptors, we utilized docked modeling. This modeling revealed that $Rg_3$ forms hydrogen bonds with amino acids, such as Ser240 of subunit I and Thr244 of subunit II and V at the channel pore, whereas $Rg_3$ localizes at the interface of the two wild-type receptor subunits. These results indicate that mutation of Leu247 to Thr247 induces conformational changes in the wild-type receptor and provides a binding pocket for $Rg_3$ at the channel pore.

Quality Properties of Fermented Squid Seasoning Manufactured with Fermentation Accelerator (발효촉진제를 첨가하여 제조한 오징어 조미료의 품질특성)

  • Choi, Seung-Hwa;Kim, Sang-Moo
    • Korean Journal of Food Science and Technology
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    • v.43 no.3
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    • pp.334-340
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    • 2011
  • Squid was fermented with fermentation accelerators to develop a natural complex seasoning. The quality properties of fermented squid were determined at different fermentation periods. Squid fermented with 10% Aspergillus oryzae koji for 10 days had the highest amino-N, acidity, and total viable cell content during fermentation periods, whereas volatile basic nitrogen content and pH were the lowest. Based on the amino-N content, squid with 10% koji fermented for 10 days was selected for further analyses. The inosine and glutamic acid contents of the fermented squid were highest innucleotide composition, their related compounds, and free amino acids, respectively. The $IC_{50}$ values of the fermented squid on DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging and ${\alpha}$-glucosidase inhibitory activities were 6.20 and 4.41 mg/mL, respectively. Based on the results of a sensory evaluation, the fermented squid seasoning was similar to other natural complex seasonings such as anchovy, cowmeat, and fisheries seasonings.