• Korean journal of applied entomology
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• v.22 no.4 s.57
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• pp.293-299
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• 1983

Experiments were carried out to elucidate the specific interactions between host plant, Phaseolus vulgaris, and symbiotic bacteria, Rhizobium Phaseoli. Purified P. vulgaris lectins and six species of cultured Rhizobium were subjected to agglutination test. Lectins from bean and R. phaseoli showed relatively high agglutination activity indicating that host plant lectins recognize carbohydrate moieties on the compatible Rhizobium cell surface. The specific carbohydrate receptors for binding of the lectins on the cell surface of R. phaseoli were found as mannose and galactose. The minimum concentration of sugars for the inhibition was 6.25mM. The lectin content of cultured plant roots was measured after germination and was maximum in 5-day seedlings. The nodulation was competitively inhibited by lectins for the plants cultured with Rhizobium cells. By immunochemical studies, there was some relationship in antigenic determinants between R. phaseoli and R. japonicum but no relationships were observed with other Rhizobium species. The results suggest that the infection by rhizobia to the roots of leguminous plants may be caused by the specific interaction of lectins with rhizobia.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.10a
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• pp.67-69
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• 1995

reverse transcription은 AIDS를 일으킨다고 알려진 바이러스인 HIV-1의 번식에는 필수적이나 인체 세포에는 필수적이 아니기에 이 단계를 표적으로 하는 AIDS 치료제가 우선적으로 개발되었다. 그 단계에 필요한 효소가 바이러스에 의해 만들어진 RT이며 이 효소의 작용을 저해하는 nucleoside 유도체들인 AZT, DDC, DDI 들이 현재 AIDS 환자의 치료에 사용되고 있다. 이들 nucleoside 유도체들은 세포안으로 들어가 triphosphate 형태로 변화된 후 dNTP와 상경적으로 경쟁하며 합성 중인 바이러스의 DNA에 들어가 DNA의 합성을 정지시켜 바이러스의 증식을 억제한다. 그러나, 이들 nucleoside 유도체들은 치료용량에서 심한 독성을 나타낼 뿐만 아니라 장기 투여시 내성을 나타내는 바이러스가 생겨나 AIDS의 치료를 불가능하게 하고 있다.

• Journal of Korea Fair Competition Federation
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• no.110
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• pp.10-22
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• 2004

최근 서울고등법원은 일련의 판결에서 상품$\cdot$용역거래와 자금$\cdot$자산거래를 구분하고, 전자에 수반하여 간접적으로 자금지원효과를 내는 행위는 자금지원행위에 포섭되지 않는다고 판시하였다. 그 논거로는 공정거래법 관련 조항의 문언이나 입법취지, 여타 불공정거래행위 규정의 사문화 우려 및 확대해석에 따른 규제의 예측가능성 위협 등이 제시되었다. 그런데 지원행위에 대한 서울고법의 ''이분법적 접근방법''(dichotomous approach)은 지원행위의 개념, 성질 및 효과, 불공정거래행위 금지의 체계 등에 비추어 부당하다. 지원행위에 관한 한 상품$\cdot$용역 거래를 자금$\cdot$자산거래와 구별할 수 있는 객관적 기준이 존재할 수 없을 뿐만 아니라, 공정거래법은 일관되게 단지 거래의 목적물뿐만 아니라 거래에 수반되는 반대급부나 결제방법 등의 관점에서 폭넓게 지원행위를 규정함으로써 상품$\cdot$용역거래에 따라 지원효과가 발생하는 경우를 염두에 두고 있기 때문이다. 또한 부당 지원 행위금지는 차별취급 등 여타 불공정 거래행위금지에 대한 특별법적 성격을 갖는 것으로서 양자가 경합할 경우 원칙적으로 전자가 우선적용 되어야 하며, 나아가 지원효과의 직$\cdot$간접성을 기준으로 지원행위 여부를 가리는 것은 지나치게 자의적인 것으로서 규제의 예측가능성을 더욱 저해하고, 수범자의 탈법행위를 용이하게 할 수 있다. 다만, 계열회사간 지원행위는 경제적 효율성을 수반할 수 있고 그 자체가 경쟁질서를 위협하는 것은 아니라는 점에서, 지원성 거래는 가능한 폭넓게 인정하되 그에 따른 부당성 내지 공정거래 저해성 판단에 신중을 기하는 방향으로 관련 조항을 해석하는 것이 바람직하다.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1304-1308
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• 1997

In the course of studies for anti-plaque agents, novel procyanidin structure isolated from Artocarpus heterophyllus folium was established by thiolysis and spectroscopic analysis. The chemical structure was identified for $(-)-epiafzelecin-(4{\beta}{\rightarrow}8)-afzelecin-(4{\alpha}-8)-catechin$ containing the trimeric flavan-3-ols and molecular weight was 833[M-H] by FAB-MS negative ion method. The inhibitory effect on the glucosyltransferase activity was investigated, novel compound showed complete inhibition at 1.0 mM and inhibited on the glucosyltransferase noncompetitively.

• Microbiology and Biotechnology Letters
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• v.12 no.4
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• pp.277-283
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• 1984

In the forward reaction (ADP formation) of the adenylate kinase from baker's yeast, dissociation constants from binary complexes are higher by a factor of about 4 times then those from at ternary complexes. In the reverse reaction, dissociation constants from the binary complexes are 2 times higher then those from the ternary complexes. The enzyme showed activities against various nucleotide triphospate in following orders; ATP 100, UTP 18, ITP 9 and GTP 5, of the necleotide monophosphate. only dAMP showed 33% activity of that AMP as phosphate acceptor. Divalent cations were required in enzyme reaction in following orders; $Mg^{2＋}$ 100, Co$^{2＋}$ 57, Mn$^{2＋}$ 54, $Ca^{2＋}$ 51, Ni$^{2＋}$ 10 and Sn$^{2＋}$ 6. AMP, as a substrate inhibitor, competitively inhibited the adenylate kinase at pH 7.2 or 8.0. Inhibition constants of the enzyme showed greater dependence on the pH of the reaction mixture, which was the lower Ki values under higher pH. Adenosine pentaphospho adenosine was competive inhibitor to the enzyme against all substrate, and it showed the same Ki values, 2.9mM. Further, PEP was competive inhibitor with respect to AMP and non-competive inhibitor with respect to MgATP. Adenylate kinase from bakers yeast was similar to mitochondrial type of animal in the contents of aianine, leucine and asparagine or asparatic acid differing from muscle type enzyme. Based on the results and observation, characteristic of yeast adenylate kinase resembled the adenylate kinase of mitochondrial type from animals. Further, difference of characteristics in adenylate kinasa depending upon the workers might be due to the difference of strain used.

• Microbiology and Biotechnology Letters
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• v.34 no.2
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• pp.121-128
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• 2006

The purified xylanase from Bacillus alcalophilus AX2000 was modified with various chemical modifiers to determine amino acid residues in the active site of the enzyme. Treatment of the enzyme with group-specific reagents such as carbodiimide or N-bromosuccinimide resulted in complete loss of enzyme activity. These results suggested that these reagents reacted with glutamic acid or aspartic acid and tryptophan residues located at or near the active site. In each case, inactivation was performed by pseudo first-order kinetics. Inhibition of enzyme activity by carbodiimide and N-bromosuccinimide showed non-competitive and competitive inhibition type, respectively. Addition of xylan to the enzyme solution containing N-bromosuccinimide prevented the inactivation, indicating the presence of tryptophan at the substrate binding site. Analysis of kinetics for inactivation showed that the loss of enzyme activity was due to modification of two glutamic acid or aspartic acid residues and single tryptophan residue.

• Journal of Applied Biological Chemistry
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• v.54 no.1
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• pp.56-62
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• 2011

Molecular docking of polyhydroxy substituted flavone analogues (1-25) as substrate molecules to the active site of tyrosinase (PDB ID: Deoxy-form (2ZMX) & Oxy-form (1WX2)) and Free-Wilson analysis were studied to understand the roles of hydroxyl substituents ($R_1-R_9$) in substrate molecules for the tyrosinase inhibitory activation. It is founded from Free-Wilson analysis that the $R_1$=hydroxyl among $R_1-R_9$ substituents had the strongest influence on the tyrosinase inhibitory activity. H-bonds between the hydroxyl substituents of substrate molecules and amino acid residues in the active site of tyrosinase were contributed to make a stable substrate-receptor complex compound. Particularly, it is proposed from the findings that the noncompetitive inhibitory activation would take place via H-bonding between peroxide oxygen (Per404) atom in the active site of tyrosinase and the hydroxyl substituents in substrate molecule.

• Journal of Korea Fair Competition Federation
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• no.125
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• pp.27-31
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• 2006

공정위는 지난해 12월 7일 마이크로소프트(MS)사의 독점규제및공정거래에 관한 법률(이하 "공정거래법"이라 함) 위반행위에 대하여 시정명령을 하고 과징금 325억원을 부과했다. MS사가 부당한 끼워팔기를 통해 경쟁사업자를 시장에서 배제하고, 소비자의 이익을 현저히 저해하였다는 것이 그 이유다. MS 사건은 공정위 역사상 가장 긴 조사와 심의를 거쳤음은 물론 고도의 법적, 경제학적, 기술적 쟁점들에 대한 치열한 공방과 심도있는 분석이 이루어진 그 의미가 매우 큰 사건이다. 본 고에서는 이러한 MS 사건의 조사단계부터 최종 의결이 있기까지 진행된 심사경위를 간략히 정리해본다.

• Applied Biological Chemistry
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• v.37 no.6
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• pp.441-446
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• 1994

Seven commercial soybean paste were tested for ACE inhibition effect. In purification of ACE inhibitor from No. 2 soybean paste, acetone fraction $(50{\sim}80%)$ had 57% protein yield with 92.8% ACE inhibition effect. Inhibitor was purified from acetone fraction of soybean paste by Sephadex G-25, Sephadex LH-20 and ODS column chromatography and HPLC. $IC_{50}$ value of the purified inhibitor was 0.6 mg/ml. The inhibitor showed the competitive inhibition patterns on ACE. Amino acid analysis showed that the peptides consist of Ala, Phe, Leu, Glu, Gly, Ser, and Asp.

• The Journal of Natural Sciences
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• v.16 no.1
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• pp.1-13
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• 2005

The angiotensin I-converting enzyme (ACE) inhibitor has anti-hypertensive effects and has long been used as prevention or remedy of hypertension. This study were carried out to produce and purify a new ACE inhibitor from recombinant E. coli and further elucidate its structure-function relationship. Recombinant pGEX-4T-3 containing ACE inhibitory peptide gene of Saccharomyces cerevisiae was transformed into E. coli BL21(DE3). Glutathione-S transferase (GST) fusion protein from E. Coli BL21(DE3) harboring the recombination pGEX-4T-3 was obtained and the ACE inhibitory peptide was purified with Sephadex G-25 column chromatography. The purified ACE inhibitory peptide was a novel decapeptide with sequence Tyr-Asp-Gly-Gly-Val-Phe -Arg-Val-Tyr-Thr which shows very low similarity to the other ACE inhibitory peptide sequence. The purified ACE inhibitor competitively inhibited ACE.