• 한국축산식품학회지
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• 제44권3호
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• pp.662-683
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• 2024

Thai-Native×Anglo-Nubian goat meat cooked by grilling (GR), sous vide (SV), and microwave (MW), was compared to fresh meat (Raw) in terms of flavor development. Non-volatile [i.e., free amino acids, nucleotide-related compounds, taste active values (TAVs) and umami equivalency, sugars, lipid oxidation, Maillard reaction products] and volatile compounds, were investigated. Notably, inosine monophosphate and Glu/Gln were the major compounds contributing to umami taste, as indicated by the highest TAVs in all samples. Raw had higher TAVs than cooked ones, indicating that heat-cooking removes these desirable flavor and taste compounds. This could be proportionally associated with the increase in aldehyde, ketone, and nitrogen-containing volatiles in all cooked samples. GR showed the highest thiobarbituric acid reactive substances (1.46 mg malonaldehyde/kg sample) and browning intensity (0.73), indicating the greatest lipid oxidation and Maillard reaction due to the higher temperature among all cooked samples (p<0.05). In contrast, SV and Raw exhibited similar profiles, indicating that low cooking temperatures preserved natural goat meat flavor, particularly the goaty odor. The principal component analysis biplot linked volatiles and non-volatiles dominant for each cooked sample to their unique flavor and taste. Therefore, these findings shed light on cooking method selection based on desirable flavor and preferences.

• 생명과학회지
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• 제22권4호
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• pp.499-507
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• 2012

군소인 Aplysia kurodai의 중추신경절로부터 발견된 myomodulin A (MMA, PMSMLRLamide)와 myomodulin E (MME, GLQMLRLamide)는 $Mytilus$ $edulis$의 anterior byssus retractor muscle (ABRM)을 활성측정시스템으로 사용하여 정제되었다. 정제된 MMA와 MME는 연체동물에서 발견된 myomodulin 계열의 펩타이드와 동일한 일차구조를 지닌다. MME의 구조와 활성간의 상관관계를 알아보기 위해서 MME, 유도체 및 다른 신경성 펩타이드들을 합성하였다. MME의 유도체인 Des[$Gly^1$]-MME, Des[$Gly^1,Leu^2$]-MME 및 Des[$Gly^1,Leu^2,Gln^3$]-MME의 일차구조는 각각 LQMLRLamide, QMLRLamide 및 MLRLamide이다. 합성 물질들을 사용하여 ABRM에 대한 phasic contraction을 측정하였다. MME는 $1{\times}10^{-9}$ M 또는 더 높은 농도에서 ABRM의 phasic contraction을 저해하였다. 또한 MME는 $1{\times}10^{-8}$ M에서 catch-tension에 대해 이완활성을 나타내었다. 합성 펩타이드들을 사용하여 Africa giant snail, $Achatina$ $fulica$의 소낭과 penial retractor muscle에 대해서도 활성을 측정하였다. MME와 유도체들은 소낭에 대해서는 수축반응을 보였지만, penial retractor muscle에 대해서는 이완 활성을 나타내었다. 이러한 결과들은 MME와 그 유도체들은 연체동물의 다양한 조직에 대해 조절 효과를 가지고 있다는 것을 의미한다. 본 연구는 생체 내에서 발생하는 신경 및 circuit의 변화를 조절하는 작용 연구에 대한 기본적인 자료가 될 것이다.

• 한국환경농학회지
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• 제12권2호
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• pp.144-152
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• 1993

오염된 하천수, 토양 및 폐기물 침출수등의 미생물 분리원으로 부터 합성세제(ABS)를 유일 탄소원으로 이용할 수 있는 미생물들을 분리하여, 이중 합성세제(ABS) 분해능이 가장 우수한 한 종의 균을 분리하여 동정한 결과 P. fluorescens 또는 그 유연균으로 밝혀졌으며, 최적 생장온도는 $30^{\circ}C$였고 최적 생장 pH는 pH 7.0이었다. 분리균주의 탄화수소 자화능 및 중금속에 대한 내성을 조사한 결과 benzene, cyclohexane, xylene 및 catechol은 탄소원으로 이용할 수 있는 반면 phenol, toluene, salicylate, naphthalene은 탄소원으로 이용하지 못하였으며, 중금속중 zinc chloride, lead nitrate, copper sulfate에 대하여는 강한 내성을 나타내었으나 mercury chloride, silver nitrate에 대하여는 내성이 약했다. 분리균의 합성세제(ABS) 분해율을 조사한 결과 ABS 20${\mu}g$/ml의 농도에서 4일후 약 55%, 100${\mu}g$/ml 농도에서는 약 60% 각각 분해되었다. 합성세제 (ABS) 분해에 따른 benzene ring의 분해율을 조사한 결과 시간이 경과 할수록 합성세제(ABS) 분해에 비례하여 benzene ring도 분해되었다. ABS 농도 20${\mu}g$/ml 및 100${\mu}g$/ml에서 benzene ring은 각각 38% 및 45% 분해되었다. COD의 분해와 ABS 분해를 비교검토한 결과 COD는 배양 24시간까지 급격하게 분해 되었으나 그 이후부터 서서히 계속해서 분해되었으며 ABS는 처음부터 서서히 계속적으로 분해되었다. ABS를 첨가하지 않고 배양한 균과 ABS를 1,000${\mu}g$/ml 농도가 되게 첨가하여 배양한 균과의 균체내 아미노산조성을 비교한 결과 아미노산총량은 각각 104.9mg/g 및 115.0mg/g으로서 ABS를 첨가하여 배양한 분리균에서 9.4% 증가 되었으며, 균체내에 Glx(Glu + Gln) 및 proline이 각각 11.1%, 9.2%로 비교적 많이 함유하고 있었고, 특히 cysteine은 ABS를 첨가하지 않고 배양한 분리균에 비해 ABS를 첨가하여 배양한 균에서 약 2.4배 높게 나타났다. ABS를 첨가하지 않고 배양한 분리균은 산성 아미노산인 Asx(Asp + Asn)와 Glx(Glu + Gln)가 비교적 많이 생성된 반면, ABS를 첨가하여 배양한 분리균에서는 염기성 아미노산인 histidine, lysine 및 argnine이 비교적 많이 생성되었다.

• Tuberculosis and Respiratory Diseases
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• 제59권3호
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• pp.257-265
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• 2005

연구 배경 : 리팜핀 내성 균주에서 리파부틴 약제의 교차 내성정도와 리팜핀 내성-리파부틴 감수성 결핵균의 rpoB 유전자 돌연변이의 특성을 알아보고자 연구를 실시하였다. 연구 방법 : 감수성검사에서 리팜핀에 내성인 균주를 선정하여 리파부틴 농도 $0-80{\mu}g/ml$ 농도로 재접종하여 감수성 여부를 확인하였다. 리팜핀-내성균주 모두 염기서열 분석을 통하여 리파부틴 감수성과의 관계를 조사하였다. 역교잡 방법으로 리파부틴 감수성균을 구별하였다. 연구 결과 : 우리나라에서 분리된 리팜핀 내성인 201균주 중에서 41균주(20.4%)는 리파부틴에 감수성을 보였다. 리파부틴 감수성을 보이는 rpoB 유전자 돌연변이는 Leu511Pro, Ser512Arg, Gln513Glu, Asp516Ala, Asp516Gly, Asp516Val, Asp516Tyr, Ser522Leu, His526Asn, His526Leu, His526Cys, Arg529Pro, Leu533Pro 등 이었다. 역교잡 방법을 이용하였을 경우 rpoB 돌연변이를 가진 균주 중에서 리파부틴 감수성균의 민감도는 92.5%이었고, 특이도는 96.1%이었다. 결 론 : 리팜핀 내성균이라도 약 20.4% (95% 신뢰구간: 14.8% to 26.0%)가 리파부틴 약제에 감수성이므로, 우리나라의 다제내성 결핵환자의 치료에서도 리파부틴이 중요한 약제로서 역할을 할 수 있음이 밝혀졌다. 향후 다제내성 결핵 환자에서의 리파부틴의 치료 효과에 대한 임상적 연구가 필요하다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.36-36
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• 2017

Out of twenty common protein amino acids, there are many kinds of non protein amino acids (NPAAs) that exist as secondary metabolites and exert ecological functions in plants. Mimosine (Mim), one of those NPAAs derived from L. leucocephala acts as an iron chelator and reversely block mammalian cell cycle at G1/S phases. Cysteine (Cys) is decisive for protein and glutathione that acts as an indispensable sulfur grantor for methionine and many other sulfur-containing secondary products. Cys biosynthesis includes consecutive two steps using two enzymes-serine acetyl transferase (SAT) and O-acetylserine (thiol)lyase (OASTL) and appeared in plant cytosol, chloroplast, and mitochondria. In the first step, the acetylation of the ${\beta}$-hydroxyl of L-serine by acetyl-CoA in the existence of SAT and finally, OASTL triggers ${\alpha}$, ${\beta}$-elimination of acetate from OAS and bind $H_2S$ to catalyze the synthesis of Cys. Mimosine synthase, one of the isozymes of the OASTLs, is able to synthesize Mim with 3-hydroxy-4-pyridone (3H4P) instead of $H_2S$ for Cys in the last step. Thus, the aim of this study was to clone and characterize the cytosolic (Cy) OASTL gene from L. leucocephala, express the recombinant OASTL in Escherichia coli, purify it, do enzyme kinetic analysis, perform docking dynamics simulation analysis between the receptor and the ligands and compare its performance between Cys and Mim synthesis. Cy-OASTL was obtained through both directional degenerate primers corresponding to conserved amino acid region among plant Cys synthase family and the purified protein was 34.3KDa. After cleaving the GST-tag, Cy-OASTL was observed to form mimosine with 3H4P and OAS. The optimum Cys and Mim reaction pH and temperature were 7.5 and $40^{\circ}C$, and 8.0 and $35^{\circ}C$ respectively. Michaelis constant (Km) values of OAS from Cys were higher than the OAS from Mim. Inter fragment interaction energy (IFIE) of substrate OAS-Cy-OASTL complex model showed that Lys, Thr81, Thr77 and Gln150 demonstrated higher attraction force for Cys but 3H4P-mimosine synthase-OAS intermediate complex showed that Gly230, Tyr227, Ala231, Gly228 and Gly232 might provide higher attraction energy for the Mim. It may be concluded that Cy-OASTL demonstrates a dual role in biosynthesis both Cys and Mim and extending the knowledge on the biochemical regulatory mechanism of mimosine and cysteine.

• Reproductive and Developmental Biology
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• 제34권1호
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• pp.33-40
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• 2010

Equine chorionic gonadotropin (eCG) is a heavily glycosylated glycoprotein composed of non-covalently linked $\alpha$- and $\beta$-subunits. To study the function and signal transduction of tethered recombinant-eCG (rec-eCG), a single chain eCG molecule was constructed, and the rec-eCG protein was prepared. In this study, we constructed 5 mutants (${\Delta}1$, ${\Delta}2$, ${\Delta}3$, ${\Delta}4$, and ${\Delta}5$) of rec-eCG using data about known glycoprotein hormones to analyze the role of specific follicle stimulating homone (FSH)-like activity. Three amino acids of certain specific sites were replaced with alanine. The expression vectors were transfected into CHO cells and subjected to G418 selection for 2~3 weeks. The media were collected and the quantity of secreted tethered rec-eCGs was quantified by ELISA. The LH- and FSH-like activities were assayed in terms of cAMP production by rat LH/CG and rat FSH receptors. Then, the metabolic clearance rate analyzed by the injection of rec-eCG (5 IU) into the tail vein was analyzed. The mutant eCGs (${\Delta}l$, ${\Delta}4$, and ${\Delta}5$) were transcripted, but not translated into proteins. Rec-eCG A2 was secreted in much lower amounts than the wild type. Only the rec-eCG ${\Delta}3$ ($\beta$-subunit: $Gln^{94}-Ile^{95}-Lys^{96}{\rightarrow}Ala^{94}-Ala^{95}-Ala^{96}$) was efficiently secreted. Although activity is low, its LH-like activity was similar to that of tethered $eCG{\beta\alpha}$. However, the FSH-like activity of rec-$eCG{\beta\alpha\Delta}3$ was completely flat. The result of the analysis of the metabolic clearance rate shoed the persistence of the mutant in the blood until 4 hours after the injection. After then, it almost disappeared at 8 hours. Taken together, these data suggest that 94~96 amino acid sequences in eCG $\beta$-subunit appear to be of utmost importance for signal transduction of the FSH receptor.

• Journal of Microbiology and Biotechnology
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• 제18권2호
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• pp.287-294
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• 2008

Three amino acid residues (His119, Glu164, and Glu338) in the active site of Thermus caldophilus GK24 ${\beta}$-glycosidase (Tca ${\beta}$-glycosidase), a family 1 glycosyl hydrolase, were mutated by site-directed mutagenesis. To verify the key catalytic residues, Glu164 and Glu338 were changed to Gly and Gln, respectively. The E164G mutation resulted in drastic reductions of both ${\beta}$-galactosidase and ${\beta}$-glucosidase activities, and the E338Q mutation caused complete loss of activity, confirming that the two residues are essential for the reaction process of glycosidic linkage hydrolysis. To investigate the role of His119 in substrate binding and enzyme activity, the residue was substituted with Gly. The H119G mutant showed 53-fold reduced activity on 5mM p-nitrophenyl ${\beta}$-D-galactopyranoside, when compared with the wild type; however, both the wild-type and mutant enzymes showed similar activity on 5mM p-nitrophenyl ${\beta}$-D-glucopyranoside at $75^{\circ}C$. Kinetic analysis with p-nitrophenyl ${\beta}$-D-galactopyranoside revealed that the $k_{cat}$ value of the H119G mutant was 76.3-fold lower than that of the wild type, but the $K_m$ of the mutant was 15.3-fold higher than that of the wild type owing to the much lower affinity of the mutant. Thus, the catalytic efficiency $(k_{cat}/K_m)$ of the mutant decreased to 0.08% to that of the wild type. The $k_{cat}$ value of the H119G mutant for p-nitrophenyl ${\beta}$-D-glucopyranoside was 5.l-fold higher than that of the wild type, but the catalytic efficiency of the mutant was 2.5% of that of the wild type. The H119G mutation gave rise to changes in optima pH (from 5.5-6.5 to 5.5) and temperature (from $90^{\circ}C\;to\;80-85^{\circ}C$). This difference of temperature optima originated in the decrease of H119G's thermostability. These results indicate that His119 is a crucial residue in ${\beta}$-galactosidase and ${\beta}$-glucosidase activities and also influences the enzyme's substrate binding affinity and thermostability.

• Asian Pacific Journal of Cancer Prevention
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• 제16권12호
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• pp.4915-4920
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• 2015

Background: : Familial adenomatous polyposis (FAP) is an autosomal dominant inherited disease mainly caused by mutations of the adenomatous polyposis coli (APC) gene with almost complete penetrance. These colorectal polyps are precancerous lesions that will inevitable develop into colorectal cancer at the median age of 40-year old if total proctocolectomy is not performed. So identification of APC germline mutations has great implications for genetic counseling and management of FAP patients. In this study, we screened APC germline mutations in Chinese FAP patients, in order to find novel mutations and the APC gene germline mutation characteristics of Chinese FAP patients. Materials and Methods: The FAP patients were diagnosed by clinical manifestations, family histories, endoscope and biopsy. Then patients peripheral blood samples were collected, afterwards, genomic DNA was extracted. The mutation analysis of the APC gene was conducted by direct polymerase chain reaction (PCR) sequencing for micromutations and multiplex ligation-dependent probe amplification (MLPA) for large duplications and/or deletions. Results: We found 6 micromutations out of 14 FAP pedigrees, while there were no large duplications and/or deletions found. These germline mutations are c.5432C>T(p. Ser1811Leu), two c.3926_3930delAAAAG (p.Glu1309AspfsX4), c.3921_3924delAAAA (p.Ile1307MetfsX13), c3184_3187delCAAA(p.Gln1061AspfsX59) and c4127_4126delAT (p.Tyr1376LysfsX9), respectively, and all deletion mutations resulted in a premature stop codon. At the same time, we found c.3921_3924delAAAA and two c.3926_3930delAAAAG are located in AAAAG short tandem repeats, c3184_3187delCAAA is located in the CAAA interrupted direct repeats, and c4127_4128 del AT is located in the 5'-CCTGAACA-3', 3'-ACAAGTCC-5 palindromes (inverted repeats) of the APC gene. Furthermore, deletion mutations are mostly located at condon 1309. Conclusions: Though there were no novel mutations found as the pathogenic gene of FAP in this study, we found nucleotide sequence containing short tandem repeats and palindromes (inverted repeats), especially the 5 bp base deletion at codon 1309, are mutations in high incidence area in APC gene,.

• Journal of Microbiology and Biotechnology
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• 제22권3호
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• pp.292-300
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• 2012

We report the expression, purification, and characterization of L-asparaginase (AnsA) from Rhizobium etli. The enzyme was purified to homogeneity in a single-step procedure involving affinity chromatography, and the kinetic parameters $K_m$, $V_{max}$, and $k_{cat}$ for L-asparagine were determined. The enzymatic activity in the presence of a number of substrates and metal ions was investigated. The molecular mass of the enzyme was 47 kDa by SDS-PAGE. The enzyme showed a maximal activity at $50^{\circ}C$, but the optimal temperature of activity was $37^{\circ}C$. It also showed maximal and optimal activities at pH 9.0. The values of $K_m$, $V_{max}$, $k_{cat}$, and $k_{cat}/K_m$ were $8.9{\pm}0.967{\times}10^{-3}$ M, $128{\pm}2.8$ U/mg protein, $106{\pm}2s^{-1}$, and $1.2{\pm}0.105{\times}10^4M^{-1}s^{-1}$, respectively. The L-asparaginase activity was reduced in the presence of $Mn^{2+}$, $Zn^{2+}$, $Ca^{2+}$, and $Mg^{2+}$ metal ions for about 52% to 31%. In addition, we found that $NH_4{^+}$, L-Asp, D-Asn, and ${\beta}$-aspartyl-hydroxamate in the reaction buffer reduced the activity of the enzyme, whereas L-Gln did not modify its enzymatic activity. This is the first report on the expression and characterization of the L-asparaginase (AnsA) from R. etli. Phylogenetic analysis of asparaginases reveals an increasing group of known sequences of the Rhizobial-type asparaginase II family.

• Journal of Biosystems Engineering
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• 제29권1호
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• pp.37-44
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• 2004

This study was conducted to develop a new drying method far reducing the drying cost and time and to investigate the drying characteristics of oak mushroom. A far infrared dryer of down draft air flow type used for this experiment can control the drying parameters, such as far infrared heater temperature and aeration velocity. The far infrared drying tests were performed at aeration velocities of 0.3 and 0.6m/s under the temperature of 90 and 100$^{\circ}C$ in for infrared heater, respectively. The results were compared and analyzed with those of an heated air drying method used as a control in terms of properties representing the drying characteristics. such as shrinkage rate, color, energy consumption amino acid components, drying rate and moisture ratio. The results obtained from this research can be summarized as follows. 1. The drying rate of far infrared drying was faster than that of heated air drying. With high temperature of far infrared heater and slow aeration velocity, the far infrared drying of down draft air flow type was superior to the heated air drying. 2. Most of far infrared drying conditions required less energy consumption than heated air drying. 3. The shrinkage rates of heated air drying and far infrared drying were decreased by 17.0% and 18.2∼19.8%, respectively. 4. The difference of color on oak mushroom surface before and after drying can be represented as $\Delta$E. $\Delta$E values of far infrared drying and heated air drying were 2.39∼4.55 and 6.77, respectively. 5. The amounts of free amino acids were higher in the far infrared than in the heated air drying. In addition the amounts of Gln and Glu generally were increased and those of Ala, Leu, and Val were decreased in order.