• 제목/요약/키워드: ${\alpha}$-amino acids

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Chemical and Textural Properties in Commercial Fermented Soybean Curds of Sufu

  • Kim, Joo-Shin;Lu, Ying;Chung, Hau-Yin
    • Preventive Nutrition and Food Science
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    • 제16권1호
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    • pp.55-61
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    • 2011
  • A survey aiming to find out the chemical and textural properties of commercial fermented soy bean curd called sufu was conducted. Sixteen brands of plain sufu produced in the Northern or the Southern part of China were collected and examined for their crude protein, crude fat, texture profiles, free amino acids, and free fatty acid contents. Twenty-one free amino acids were extracted and derivatized using a commercial kit followed by separation and analyzed by the gas chromatography-mass spectrometry (GC-MS). Similarly, ten free fatty acids were extracted using alumina, eluted, separated and analyzed. The content ranges of crude fat and protein were 22~36% and 31~38%, respectively. In texture profile analysis, ranges of the texture parameters were 131~493 g (hardness), 0.4~0.5 (cohesiveness), -137 to -50 gs (adhesiveness), 0.6~1 (springiness), 47~220 g (gumminess) and 32~177 g (chewiness). Twenty-one different free amino acids, especially alanine, glycine, $\alpha$-aminobutyric acid, valine, leucine, allo-isoleucine, aspartic acid, glutamic acid and lysine in large amount, as well as ten fatty acids in total, notably linoleic acid (9-octadecanoic acid), oleic acid (9,12-octadecadienoic acid), linolenic acid (9,12,15-octadecadienoic acid), hexadecanoic acid and octadecanoic acid were found. This information provides important quality reference ranges for product developers and manufacturers to optimize and produce the plain sufu.

N,N'-Dimethylethylenediamine-N,N'-di-${\alpha}$-butyric acid 의 세자리 리간드 아미노산 코발트 (III) 착물 (Trifunctional Amino Acid-Co(III) Complexes of N,N'-Dimethylethylenediamine-N,N'-di-${\alpha}$-butyric Acid)

  • 전무진;정해권;정진승
    • 대한화학회지
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    • 제33권5호
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    • pp.504-509
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    • 1989
  • N,N'-dimethylethylenediamine-N,N'-di-${\alpha}$-butyric acid(dmedba)와 세자리 아미노산과의 코발트(III) 착물인 [Co(dmedba)(L-aa)] (L-aa = S-methyl-L-cysteine, L-methionine, L-glutamic acid, L-aspartic acid)는$ s-cis-[Co(dmedba)Cl_2]-^ 착물과 아미노산과의 반응으로부터 얻었다. 아미노산들은 [Co(dmedda)(L-dd)] 착물과 같이 아민과 카르복실그룹을 통하여 배위되었다. 이 착물들의 구조는 ^1H-NMR, IR, UV$ 스펙트럼 데이타와 원소분석으로 확인하였다.

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수출용 가지의 염절임 중 품질변화 (Changes in Quality of Eggplants during Salting)

  • 윤경영;홍주연;김광수;신승렬
    • 한국식품저장유통학회지
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    • 제13권3호
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    • pp.322-328
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    • 2006
  • 본 연구는 가지의 수출 경쟁력을 높이기 위한 방안으로 수출용 가지인 축양과 시키부 품종을 염가공품으로 개발하고자 하였다. 이를 위해 가지에 미강과 소금을 혼합하여 $4^{\circ}\C$에서 7일간 염절임하고, 염절임 중 가지의 색도, 유기산, 아미노산 및 무기질 함량의 변화를 조사하였다. 염절임이 진행될수록 가지의 L값과 b값은 감소하였으며, a값은 증가하였다. Acetic acid, citric acid, lactic acid, malic acid 그리고 succinic acid가 분리정량 되었으며, 이 중 acetic acid와 malic acid가 대부분을 차지하였다. 염절임이 진행될수록 acetic acid와 malic acid의 함량은 감소하였으며, citric acid와 succinic acid의 함량은 증가하였다. 주요한 구성아미노산은 alanine, glycine, valine, leucine이었으며, 염절임이 진행될수록 축양 품종의 총 아미노산 함량은 감소하였고, 시키부품종의 총 아미노산 함량 변화는 없었다. 주요한 유리아미노산은 aspartic acid, valine, leucine, lysine, arginine이었으며, 염절임이 진행되는 동안 유리아미노산의 함량은 증가하였다. 주요한 유리아미노산 유도체는 $\gamma$-aminobutyric acid 이었으며, 염절임이 진행될수록 $\alpha$-aminoadipic acid와 $\gamma$-aminobutyric acid의 함량이 증가하였다. 가지에 함유된 무기질 중 칼륨과 나트륨의 함량이 가장 많았으며, 염절임이 진행될수록 나트륨, 마그네슘 및 칼슘의 함량이 크게 증가하였다.

Capsaicin이 연수후각의 흥분성 아미노산 전달물질에 미치는 영향 (Effect of Capsaicin on the Excitatory Amino Acids Neurotranmitters in Medullary Dorsal Horn)

  • 권수경;윤수한;이종흔
    • Restorative Dentistry and Endodontics
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    • 제19권2호
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    • pp.621-632
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    • 1994
  • This experiment was performed to study the effect of capsaicin on the excitatory amino acids (EAAs) neurotransmitter in medullary dorsal horn and to clarify the relationship between substance P and excitatory amino acids. Horizontal slice of rat medullary dorsal horn was prepared and perfused with modified Krebs-Ringer solution in brain slice chamber. Release of EAAs was induced by veratrine and capsaicin were added to perfusion solution to observe the changes in EAA release. Capsaicin and ruthenium red, capsaicin antagonist, were also systemically injected with 50mg/kg in first day and 100mg/kg in second day for 2 days. Medulla oblongata containing the medullary dorsal horn was isolated, homogenized and centrifused. Spernatant was freeze-dried and EAA was determined by HPLC. Release of glutamate and aspartate was significantly increased by veratrine or capsaicin, but veratrine evoked release of EAAs was blocked by capsaicin in vitro, and injected ruthenium red did not have effect on the contents of EMs in vivo. Systemically injected capsaicin evoked the slight decrease in content of glutamate and aspartate in medullary dorsal horn and this effect of capsaicin was unaffected by ruthenium red.

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Biological Functions of the COOH-Terminal Amino Acids of the $\alpha$-Subunit of Tethered Equine Chorionic Gonadotropin

  • Jeoung, Youn-Hee;Yoon, Jong-Taek;Min, Kwan-Sik
    • Reproductive and Developmental Biology
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    • 제34권1호
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    • pp.47-53
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    • 2010
  • Glycoprotein hormones have a common $\alpha$-subunit that is involved in the signaling pathway together with G protein, adenylcyclase and cAMP induction; however, it is an unclear how this common structure is related to hormonal action. To determine the biological functions of the COOH-terminal amino acids in the $\alpha$-subunit of these glycoprotein hormones, a tethered-molecule was constructed by fusing the $NH_2$-terminus of the $\alpha$-subunit to the COOH-terminus of the $\beta$-subunit of equine chorionic gonadotropin (eCG). The following deletion mutants were created by PCR; Ile was inserted at position 96 to form ${\Delta}96$, Lys was substituted at position 95 to form ${\Delta}95$, His was inserted at position 93 to form ${\Delta}93$ and Tyr was substituted at position 87 to form ${\Delta}87$. Each mutant was transfected into CHO-K1 cells. Tethered-wt eCG, and ${\Delta}96$, ${\Delta}95$, and ${\Delta}93$ mutants were efficiently secreted into the medium but the ${\Delta}87$ mutant was not secreted. Interestingly, the RT-PCR, real-time PCR, and northern blot analyses confirmed that the RNA was transcribed in the ${\Delta}87$ mutant. However, the ${\Delta}87$ mutant protein was not detected in the medium or the intracellular fraction of the cell lysates. The LH- and FSH-like activities of the recombinant proteins were assayed in terms of cAMP production using rat LH/CG and rat FSH receptors. The metabolic clearance rate (MCR) was determined by injecting rec-eCG (2 IU) into the tail vein. The ${\Delta}95$ and ${\Delta}93$ mutants were completely inactive in both the LH- and FSH-like activity assays. The ${\Delta}96$ mutant showed slight activity in the LH-like activity assay. In comparison to the wild type, the activity of the ${\Delta}96$ mutant in the FSH-like activity assay was the highest among all the mutants. The MCR assay in which rec-eCG was injected showed a peak at 10 min in all the treatment groups, which disappeared 4 h after injection. These results imply a direct interaction between the receptor and the COOH-terminal region of the a-subunit. The data also reveal a significant difference in the mechanism by which the eCG hormone interacts with the rLH and rFSH receptors. The COOH-terminal region of the $\alpha$-subunit is very important for the secretion and functioning of this hormone.

New Gene Cluster from Thermophile Bacillus fordii MH602 for Conversion of DL-5-Substituted Hydantoins to L-Amino Acids

  • Mei, Yan-Zhen;Wan, Yong-Min;He, Bing-Fang;Ying, Han-Jie;Ouyang, Ping-Kai
    • Journal of Microbiology and Biotechnology
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    • 제19권12호
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    • pp.1497-1505
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    • 2009
  • The thermophile Bacillus fordii MH602 was screened for stereospecifically hydrolyzing DL-5-substituted hydantoins to L-$\alpha$-amino acids. Since the reaction occurs at higher temperature, the advantages for enhancement of substrate solubility and for racemization of DL-5-substituted hydantoins during the conversion were achieved. The hydantoin metabolism gene cluster from thermophile is firstly reported in this paper. The genes involved in hydantoin utilization (hyu) were isolated on an 8.2-kb DNA fragment by restriction site-dependent PCR, and six ORFs were identified by DNA sequence analysis. The hyu gene cluster contained four genes with novel cluster organization characteristics: the hydantoinase gene hyuH, putative transport protein gene hyuP, hyperprotein gene hyuHP, and L-carbamoylase gene hyuC. The hyuH and hyuC genes were heterogeneously expressed in E. coli. The results indicated that hyuH and hyuC are involved in the conversion of DL-5-substituted hydantoins to an N-carbamyl intermediate that is subsequently converted to L-$\alpha$-amino acids. Hydantoinase and carbamoylase from B. fordii MH602 compared respectively with reported hydantoinase and carbamoylase showed the highest identities of 71% and 39%. The novel cluster organization characteristics and the difference of the key enzymes between thermopile B. fordii MH602 and other mesophiles were presumed to be related to the evolutionary origins of concerned metabolism.

측백 열매에 관한 연구(3);과피의 물 추출액을 알카리로 처리할 때의 지방산과 아미노산 분석 (Studies of the Thuja Orientalis(3);Amino Acid and Fatty Acid Composition in the Thuja Biotae Water Extract Treated with Alkaline)

  • 남현근
    • 한국응용과학기술학회지
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    • 제5권2호
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    • pp.9-15
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    • 1988
  • In order to investigate the amino acid and fatty acid content in Thuja biotae water extract treated with alkaline, it was performed. There are 16 kinds of different amino acid and 20 kinds of different fatty acid in Thuja biotae water extract. An aspartic acid was contained 52% and proline was contained 10%, particulary, r-aminobutyric acid was analysed. Essential fatty acids; linoleic acid, linolenic acid and arachidonic acid were cotained a lot amount. There are 11 different unknown materials which were identified by GC-MS spectrum, such as N-[($4{\alpha},5{\alpha}$)-cholestan-4-yl]-acetamide; 22,26-Epithio-furost-5-en-3-ol; 2-Methyl-6-(4-methyl-3-cyclohexen-1-yl)-4-heptanone; 3,12,14-Tris(acetyloxy)-pregnane-15,20-dione;22-Methyl-26-thio-furost-5-en-3-ol; 7-Ethenyl-1,2,3,4,4a,4b,5,6,7,9,10,10a-dodecahydro-1,4a,7-trimethyl-1-phenanthrene carboxyaldehyde; Methoxyiminopro-panedioic acid; 13-Methyl-13-${\beta}$-Methyl-13-vinyl-dodecaarp-7-en-3-3-ol; 22-Methyl-26-thio-furost-6-methyl-3-ol; $5{\alpha}-Androstane-2$,11-dione; 9-Methyl-heptadecanoic acid.