• Archives of Pharmacal Research
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• 제9권2호
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• pp.63-73
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• 1986

The use of biodegradable polymetric materials as drug carriers is a relatively new dimension in polymeric drug delivery systems. A number of biodegradable or bioerodible polymers, such as poly(lactic/glycolic acid) copolymer, poly($\alpha$-amino acid), polyanhydride, and poly (ortho ester) are currently being investigated for this purpose. These polymers are useful for matrix and reservoir-type delivery devices. In addition, when chemical functional groups are introduced to the biodegradable polymer backdone, such as poly (N-(2-hydroxypropyl) methacrylamide), the therapeutic agent can be covalently bound directly or via spacer to the backbone polymer. These polymer/drug conjugates represent another new dimension in biodegradable polymeric drug delivery systems. In addition, examples of biodegradable polymeric durg delivery systems currently being investigated will be discussed for the purpose of demonstrarting the potential importance of this new field.

• Bulletin of the Korean Chemical Society
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• 제13권2호
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• pp.135-139
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• 1992

The mono(aryl)cyanoplatinum(II) complex $[Pt(CN)(C_6H_3{CH_2NMe_2}_2-26)]$, reacts with the dihalogens to yield the mono(aryl)cyanoplatinum complexes $[PtX_2(CN)(C_6H_3{CH_2NMe_2}_2-26)]$, (X = Cl, Br, I). The structural configuration of the two halogen atoms for a square planar platinum complex was studied by 1H-NMR spectroscopy and led to a mixture of trans and cis orientation. The trans orientation was found to be more stable in energy (1.33 kcal/mol) than the cis orientation by means of Extended H ckel calculations. On the base of a combination of the analysis of $^1H-NMR$, $^{13}C-NMR spectra and computational calculations it is assumed that the intermediate consists of an initial attack in the linear transition state, leading to the $S_{N}2$ type mechanism.

• 한국응용과학기술학회지
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• 제10권2호
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• pp.81-90
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• 1993

The Surfactants composed of acylated aterocollagen which is produced by the acylation of the side chain amino radicals of aterocollagen with an aliphatic acid having 12 to 18 carbon atoms will be discussed in this study. This condensation is done at moderate reaction temperature (<$25^{\circ}C$) in aqueous alkaline solution. The products of this reaction were identified by UV/VIS spectroscopy and infrared spectroscopy. For these compounds, surface active properties and physical properties including isoelectric point, Krafft point, surface tension, critical micelle concentration(cmc), foaming power, viscosity behaviour, water holding capacity, skin irritation and emulsifying power were measured respectively. The experimental results received that the products have a good emulsifying power, excellent water holding capacity while having low skin irritation. Thus, these derivatives will be expected to be used as an emulsifying agent for O/W type cosmetic emulsion.

• BMB Reports
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• 제37권5호
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• pp.597-602
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• 2004

N-terminal His-tagged recombinant $\beta$-1,4-galactosyltransferase from Neisseria meningitidis was expressed and purified to homogeneity by column chromatography using Ni-NTA resin. Mutations were introduced to investigate the roles of, Ser68, His69, Glu88, Asp90, and Tyr156, which are components of a highly conserved region in recombinant $\beta$-1,4 galactosyltransferase. Also, the functions of three other cysteine residues, Cys65, Cys139, and Cys205, were investigated using site-directed mutagenesis to determine the location of the disulfide bond and the role of the sulfhydryl groups. Purified mutant galactosyltransferases, His69Phe, Glu88Gln and Asp90Asn completely shut down wild-type galactosyltransferase activity (1-3%). Also, Ser68Ala showed much lower activity than wild-type galactosyltransferase (19%). However, only the substitution of Tyr156Phe resulted in a slight reduction in galactosyltransferase activity (90%). The enzyme was found to remain active when the cysteine residues at positions 139 and 205 were replaced separately with serine. However, enzyme reactivity was found to be markedly reduced when Cys65 was replaced with serine (27%). These results indicate that conserved amino acids such as Cys65, Ser68, His69, Glu88, and Asp90 may be involved in the binding of substrates or in the catalysis of the galactosyltransferase reaction.

• 분석과학
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• 제25권3호
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• pp.171-177
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• 2012

Luminol-$H_2O_2$-Cu(II) 시스템을 이용한 화학발광법을 사용하여 방향족 아미노산인 트립토판, 타이로신 및 페닐알라닌의 정량분석을 하였다. 세 종류의 방향족 아미노산(트립토판, 타이로신, 페닐알라닌)을 luminol-$H_2O_2$-Cu(II) 시스템에 첨가하였을 때 아미노산이 존재하지 않을 때보다 화학발광세기가 더욱 증가하는 현상을 관찰하였으며, 이러한 현상을 이용하여 각 방향족 아미노산을 정량분석 하였다. 방향족 아미노산의 최적분석 조건을 조사하기 위하여, Cu(II) 이온 촉매에 의한 루미놀과 과산화수소의 화학발광반응에 미치는 아미노산의 반응속도론적 영향을 조사하였고 과산화수소와 Cu(II) 이온의 농도 그리고 pH와 완충용액의 영향을 조사하였다. 루미놀 화학발광 시스템의 최적 분석조건 하에서 수용액 중의 방향족 아미노산 정량분석을 위해 얻은 검정곡선에서 직선성이 성립하는 농도 범위는 각각 트립토판은 $1.0{\times}10^{-6}{\sim}2.0{\times}10^{-5}\;M$, 타이로신은 $1.0{\times}10^{-6}{\sim}2.0{\times}10^{-5}\;M$ 그리고 페닐알라닌은 $2.0{\times}10^{-6}{\sim}2.0{\times}10^{-5}\;M$이었으며, 이 구간에서 각 아미노산에 대한 상대표준편차(n = 4)는 순차적으로 3.21%, 2.64% 그리고 2.48%이었다. 그리고 각 아미노산의 검출한계($3{\sigma}/s$)는 트립토판 $6.8{\times}10^{-7}\;M$, 타이로신 $5.7{\times}10^{-7}\;M$, 페닐알라닌 $9.6{\times}10^{-7}\;M$이었다.

• 한국자기공명학회논문지
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• 제16권1호
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• pp.34-45
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• 2012

Melanocortin-4 receptor (MC4R) subtype is associated with obese humans. Especially, in a patient with severe early-onset obesity, novel heterozygous mutation in the MC4R gene was detected, resulting in an exchange of aspartic acid to asparagine in $90^{th}$ amino acid residue located in the predicted second trans-membrane domain (TM2). Mutations in the melanocortin-4 receptor (MC4R) gene are the most frequent monogenic causes of severe obesity which have been described as heterozygous with loss of function. In order to compare structure difference between MC4R wild type (MC4R-TM2-wt) and mutant (MC4R-TM2-D90N), we designed both MC4R-TM2-wt and MC4R-TM2-D90N construct in pET 21b vector. In this study, we optimized high-yield purification procedure for recombinant TM2-D90N. Eluted recombinant protein was resolubilized under urea condition for thrombin cleavage reaction and we conducted the high-performance liquid chromatography (HPLC) with reverse phase column under 1% acetonitrile, 0.01% TFA buffer solution. The molecular size of purified target peptide was confirmed by Tricine-SDS page analysis. To characterize MC4R-TM2-D90N, we have performed $^{15}N$-isotope labeling of peptide using M9 media and purified labeled target peptide for hetero-nuclear NMR spectroscopy.

• Applied Biological Chemistry
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• 제17권3호
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• pp.149-176
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• 1974

팔종(八種)의 치환(置換) diphenyl ether 제초제(除草劑)를 Rayonet 광화학(光化學) 반응기(反應器)를 사용(使用)한 모조환경조건하(模造環境條件下)에서 용액상(溶液相) 광분해(光分解)시켜 그 분해산물(分解産物)에 관(關)하여 연구(硏究)하였다. 시료(試料)로 사용(使用)된 화합물(化合物)들은 300 nm에서 광화학반응(光化學反應)을 일으키기에 충분(充分)한 energy를 흡수(吸收)하였으며 분해산물(分解産物)은 tlc, glc, ir, ms, 그리고 nmr 등(等)에 의(依)하여 확인(確認)하였다. 그 결과(結果)를 요약(要約)하면 C-6989의 용액상(溶液相) 광분해(光分解) : p-nitrophenol이 다량(多量) 생성(生成)됨을 보아 ether결합(結合)의 결렬이 주반응(主反應)이며 치환기(置換基) $NO_2{\rightarrow}NH_2$의 광화학적(光化學約) 환원반응(還元反應)과 $CF_3{\rightarrow}COOH$의 산화반응(酸化反應)도 관찰되었다. p-Nitrophenol의 수중(水中) 광분해(光分解) : quinone(0.28%), hydroquinone(0.66%) 및 p-aminophenol(0.42%)과 비교적(比較的) 소량(少量)의 미지화합물(未知化合物)이 생성(生成)됨을 확인(確認)하였고 모화합물(母化化合物)은 대부분(大部分) 작용(作用)을 받지 않은 채로 존재(存在)하였다. 이들 분해산물(分解産物)의 형성기구(形成機構)는 $n{\rightarrow}{\pi}^*$ 및 여기(勵起)를 거친 nitro-nitrite재배열(再配列) 및 자유기(自由基)에 의(依)한 수소탈취(水素脫取)를 통(通)한 광환원(光還元)으로 추측(推測)되었다. Nitrofen의 용액상(溶液相) 광분해(光分解) : n-hexane중(中)에서는 $NO_2$기(基)의 광환원(光遷元)이 주반응(主反應)이었고 수용액(水溶液) 중(中)에서는 광환원(光遷元) 및 hydroxylation이 ether결합(結合) 결렬 보다 현저하였다. hydroxide ion에 의한 친핵적(親核的) 치환(置換), hydroxyl기(基) 및 소량(少量)이긴 하지만 수소(水素)에 의한 염소(鹽素)의 치환(置換)도 다소 관찰되었다. MO-338의 용액상(溶液相) 광분해(光分解) : n-hexane용액중(中) nitro기(基)의 광환원(光遷元) 반응(反應)과 수용액중(水溶液中)에서의 광환원(光遷元) 및 hydroxylation이 주반응(主反應)이었으며 hydroxyl기(基)와 수소(水素)에 의(依)한 염소(鹽素)의 치환(置換) 및 ether결합(結合)의 결렬도 볼 수 있었다. n-Hexane과 cyclohexane중(中)에서의 MC-4379, MC-3761, MC-5127, MC-6063 및 MC-7181의 광분해(光分解) : nitro기(基)의 광환원반응(光還元反應)과 수소(水素)에 의(依)한 halogen의 치환반응(置換反應)이 주(主)로 일어났다. MC-4379의 수중(水中) 광분해(光分解) : ether결합(結合)의 결렬, hydroxyl기(基)에 의한 carboxymethyl기(基)의 치환(置換), hydroxylation, hydroxyl기(基)에 의한 nitro기(基)의 치환(置換)이 주(主)로 일어났고 광환원(光還元) 및 광염소화반응(光鹽素化反應)도 약간 일어났다. MC-3761의 수중(水中) 광분해(光分解) : ether결합(結合)의 결렬, hydroxyl기(基)에 의한 carboxymethyl기(基)의 치환(置換) 및 hydroxylation이 수반되는 광환원(光還元)이 주반응(主反應)이었다. MC-5127의 수중(水中) 광분해(光分解) : 수소(水素)에 의한 carboxyethyl기(基)의 치환(置換)이 현저 하였고 ether결합(結合)의 결렬, 광환원(光還元) 및 탈염소화반응(脫鹽素化反應)도 약간 관찰되었으며 decarboxyethylation은 decarxy-methylation보다 용이함을 볼 수 있었다. MC-6063의 수중(水中) 광분해(光分解) : ether결합(結合)의 결렬과 탈염소화반응(脫鹽素化反應)이 주(主)로 관찰되었다. MC-7181의 수중(水中) 광분해(光分解) : 수소(水素)에 의한 carboxymethyl기(基)의 치환(置換)과 monodechlorination이 현저하였고 ether결합(結合) 결렬과 hydroxylation도 약간 일어났다. 3-Carboxymethyl-4-nitrophenol의 수중(水中) 광분해(光分解) : 방향족(芳香族) ester에서 흔히 볼 수 있는 광유도(光誘導) Fries rearrangement는 이 화합물(化合物)의 carboxymethyl기(基)에서는 볼 수 없었고 $nitro{\to}nitroso$반응(反應)이 주(主)로 일어났다.

• Journal of Animal Science and Technology
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• 제57권3호
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• pp.11.1-11.8
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• 2015

An experiment was conducted to evaluate apparent (AID) and standardized (SID) ileal digestibilities of crude protein (CP) and amino acids (AA) with 6 soybean products in weaning pigs. A total of 14 weaning barrows with an initial body weight of $6.54{\pm}0.34kg$ were fitted with T-cannula at the distal ileum and allotted to 7 diets containing various soybean products. The soybean products used in the experiment were conventional soybean meal (CSBM), SBM fermented by Aspergillus oryzae GB-107 (FSBMA), SBM fermented by Bacillus subtilis PP6 (FSBMB), UV sterilized SBM fermented by Bacillus subtilis PP6 (UVFSBMB), SBM containing Bacillus subtilis PP6 (PSBM), and soy protein concentrate (SPC). Six corn-based diets were used and each of soybean products was added. All diets contained 5.0 g/kg of chromic oxide as an indigestible indicator and an N-free diet was used to measure basal endogenous losses of CP and AAs. Ileal CP digestibility did not differ by different soybean products. However, SIDs of Ile, Phe and Val were improved in pigs fed the FSBMB, UVFSBMB and SPC diets and the pigs fed the FSBMA diet showed higher SIDs of Phe and Val compared with those fed the CSBM diet (P < 0.05). The FSBMB diet had higher SIDs in most AAs compared with the FSBMA diet (P < 0.05), and higher SIDs of Lys, Ala, Pro, Ser, and Tyr compared with PSBM diet (P < 0.05). However, there was no response of UV-sterilization on the FSBMB in the SIDs of AAs. These results suggest that SIDs of AAs could be improved by the supplementation of fermented soybean products in the diet for weaning pigs but fermentation with Bacillus subtilis is more efficient in improving ileal AA digestibility than that with Aspergillus oryzae. Furthermore, probiotics supplementation in the CSBM and UV-sterilization of the FSBMB had no effects on chemical composition and ileal AA digestibility.

• 미생물학회지
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• 제46권4호
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• pp.383-388
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• 2010

알칼리성 단백질 분해효소 고생산 돌연변이 균주 Vibrio metschnikovii L12-23, N4-8, KS1으로부터 알칼리성 단백질 분해효소를 암호화하는 vapK (Vibrio alkaline protease K) 유전자들을 PCR에 의하여 분리한 다음 DNA shuffling, error-prone PCR 방법과 같은 분자진화 기술을 통해 고활성 단백질 분해효소를 생산하는 재조합 V. metschnikovii 균주를 제작하였다. DNA shuffling 방법을 통해 변형시킨 vapK-1 유전자와 이 유전자를 주형으로 error-prone PCR 기법을 통해 재 변형된 vapK-2 유전자를 cloning한 후 V. metschnikovii KS1 균주에 역도입하여 재조합 균주를 제조하였다. 재조합 균주들의 단백질 분해 능력을 조사한 결과 vapK-2 유전자가 2 copy 도입된 재조합 균주의 경우 야생형 균주인 V. metschnikovii RH530에 비해 43.6배 높은 단백질 분해활성을 보였으며 숙주인 V. metschnikovii KS1에 비해 약 3.9배 향상된 단백질 분해 활성을 확인할 수 있었다. 변형된 vapK-1과 vapK-2 유전자를 야생형 vapK 유전자의 염기서열을 비교 분석한 결과 단백질 분해 능력의 활성에 영향을 미치는 active site를 제외한 부분에서 변화가 일어났음을 확인 할 수 있었다. 변형된 유전자 vapK-1을 two copy를 포함한 재조합 플라스미드를 가진 V. metschnikovii KS1을 30 L fermentor로 배양 하였을 때 배양 후 35 시간에 18,000 PU/ml의 활성을 보였으며, 이는 향후 산업용 균주로서 사용될 수 있는 가능성을 제시하였다.

• 한국수산과학회지
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• 제55권6호
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• pp.777-790
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• 2022

This study was conducted to investigate the nutritional characteristics of the following Korean-distributed fish species commonly consumed as sliced raw fish (CC-SRF): olive flounder Paralichthys olivaceus (OF), red sea bream Pagrus major (RS), Atlantic salmon (AS), coho salmon (CS) and sockeye salmon (SS). The crude protein and lipid contents of OF, RS, AS, CS and SS were 20.2% and 5.5%, 21.2% and 6.8%, 17.7% and 18.5%, 18.3% and 16.1%, and 20.4% and 5.7%, respectively. Regardless of the type and weight of fish species, the major amino acids were leucine, lysine, aspartic acid, and glutamic acid, whereas histidine was identified as a limiting amino acid. The major minerals in all CC-SRF were P, K and Se based on the recommended daily intake or sufficient intake for Korean males aged between 19-49 years. Among the different types of all CC-SRF, the intake of OF and SS lipids is predicted to be associated with a lower n-6/n-3 fatty acid ratio, whereas among the free amino acids, which are expected to have health functionality, we identified taurine in OF and RS, and anserine in salmons. The digestibility of OF, RS, AS, CS and SS were 60.7%, 54.9%, 48.5%, 49.6%, and 53.4%, respectively.