• Journal of the Korean Chemical Society
• /
• v.66 no.6
• /
• pp.509-520
• /
• 2022

This study investigated the impact of elementary school science classes based on collaborative problem-solving on the character competency of students. For this purpose, students from 2 classes in 5^th grade at an elementary school in a metropolitan city were targeted, and elementary science classes based on collaborative problem-solving were developed and applied to the 5 topics selected from the 'dissolution and solution' unit in the elementary science curriculum. In order to investigate the effect of science class based on collaborative problem-solving on the character competency of students, results of the character competence test before and after the class, reflective writing activity sheets filled out by the students in the experimental group, and questionnaires regarding their changes in character competency after the class were analyzed. The results showed that elementary science classes based on collaborative problem-solving were effective in cultivating the character competence of elementary school students.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.9
• /
• pp.2671-2674
• /
• 2013

To elucidate the role of the evolutionarily conserved Tyr8 residue in rice Phi-class GSTF3, this amino acid was replaced with alanine and phenylalanine by site-directed mutagenesis, respectively. The replacement of Tyr8 with Ala significantly affected the catalytic activity and the kinetic parameters, whereas the substitutions of Tyr8 with Phe had almost no effect. The Y8A mutant resulted in approximately 90-100% decrease of the specific activity. Moreover, the Y8A mutant resulted approximately in 2-fold increase of $K_m$, approximately 60-80% decrease of $k_{cat}$, and approximately 6.5-fold decrease in $k_{cat}/K_m$. From the pH/log $k_{cat}/K_m$ plot, $pK_a$ values of the GSH in the wild-type enzyme-GSH complex, Y8A-GSH complex and Y8F-GSH complex were estimated to be approximately 6.8, 8.5 and 6.9, respectively. From these results, we suggest that the evolutionarily conserved Tyr8 residue in OsGSTF3 seems to influence the structural stability of the active site of OsGSTF3 rather than directly its catalytic activity.

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2002.10a
• /
• pp.193-194
• /
• 2002

Angiotensin I converting enzyme (ACE) inhibitor was purified from Crassostrea gigas. The ACE belongs to the class of metalloprotease. This enzyme plays an important physiological role in regulating blood pressure of the rennin-angiotensin system by converting from angiotensin I to octapeptide angiotensin II, a potent vasoconstrictor and by inactivating bradykinin, which has depressor action. (omitted)

• Journal of the Korean Chemical Society
• /
• v.58 no.3
• /
• pp.313-323
• /
• 2014

The purpose this research was to develop the practicum-affiliated coursework for pre-service chemistry teachers to enhance their instructional professionalism. The researchers developed the syllabus and the materials of the practicum-affiliated coursework and opened the class 'Practice of Chemistry Lesson' for the pre-service chemistry teachers who were expected to participate in the practicum. Semi-constructed individual interviews revealed that pre-service chemistry teachers thought the developed coursework, which linked science education theory and practice, helped them to develop educational connoisseurship about good science class and to be prepared practically to the practicum, and as the result, they could enhance their teaching ability. The result identified that the reconstruction of the practicum experience through the process of 5 steps of the curriculum could develop the instructional professionalism of pre-service chemistry teachers.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.9
• /
• pp.2497-2502
• /
• 2010

Arg13 is a conserved active-site residue in all known Pi class glutathione S-transferases (GSTs) and in most Alpha class GSTs. To evaluate its contribution to substrate binding and catalysis of this residue, three mutants (R13A, R13K, and R13L) were expressed in Escherichia coli and purified by GSH affinity chromatography. The substitutions of Arg13 significantly affected GSH-conjugation activity, while scarcely affecting glutathione peroxidase or steroid isomerase activities. Mutation of Arg13 into Ala largely reduced the GSH-conjugation activity by approximately 85 - 95%, whereas substitutions by Lys and Leu barely affected activity. These results suggest that, in the GSH-conjugation activity of hGST P1-1, the contribution of Arg13 toward catalytic activity is highly dependent on substrate specificities and the size of the side chain at position 13. From the kinetic parameters, introduction of larger side chains at position 13 results in stronger affinity (Leu > Lys, Arg > Ala) towards GSH. The substitutions of Arg13 with alanine and leucine significantly affected $k_{cat}$, whereas substitution with Lys was similar to that of the wild type, indicating the significance of a positively charged residue at position 13. From the plots of log ($k_{cat}/{K_m}^{CDNB}$) against pH, the $pK_a$ values of the thiol group of GSH bound in R13A, R13K, and R13L were estimated to be 1.8, 1.4, and 1.8 pK units higher than the $pK_a$ value of the wild-type enzyme, demonstrating the contribution of the Arg13 guanidinium group to the electrostatic field in the active site. From these results, we suggest that contribution of Arg13 in substrate binding is highly dependent on the nature of the electrophilic substrates, while in the catalytic mechanism, it stabilizes the GSH thiolate through hydrogen bonding.

• Journal of Korean Society for Atmospheric Environment
• /
• v.22 no.6
• /
• pp.808-820
• /
• 2006

In regard to indoor air quality patterns, the government introduced various polices that were about managing and monitoring quality of indoor air as a major assignment, and also executed 'Indoor Air Quality Management Act' which was presented in the May, 2004. However, among the multi-usage facilities controlled by the Act, the school was not included yet. This study goal was to investigate PM 10 pollution patterns of the high school classrooms using a pattern recognition method based on cluster analysis and disjoint principal component analysis, and further to survey levels of inorganic elements in May, June, and September, 2004. A hierarchical clustering method was examined to obtain possible objects in pseudo homogeneous sample classes by transformation raw data and by applying various distance. Following the analysis, the disjoint principal component analysis was used to define homogeneous sample class after deleting outliers. Then three homogeneous Patterns were obtained as follows: the first class had been separated and objects in the class were considered to be sampled under semi-open condition. This class had high concentration of Ca, Fe, Mg, K, Al, and Na which are related with a soil and a chalk compounds. The second class was obtained in which objects were sampled while working air-conditioners and was identified low concentration of PM 10 and elements. Objects in the last class were assigned during rainy day. A chalk, soil element and various types of anthropogenic sources including combustions and industrial influenced the third class. This methodology was thought to be helpful enough to classify indoor air quality patterns and indoor environmental categories when controlling an indoor air quality.

• Bulletin of the Korean Chemical Society
• /
• v.33 no.11
• /
• pp.3875-3878
• /
• 2012

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1995.04a
• /
• pp.64-64
• /
• 1995

Cholesteryl Ester Transfer Protein (CETP) mediates the transfer of cholesterol ester and triglyceride between high-density lipoprotein (HDL) and other low-density lipoproteins, therefore, it might influence HDL levels. The levels of HDL is closely related to the atherogenic diseases in human and there were several reports that the trasgenic mice expressing CETP had much worse atherosclerosis than non-expressing control one. Therefore, selective inhibitors of CETP have the potential to be used as antiatherosclerotic agents. Continued screening for potent inhibitors of CETP led to the isolation of Suberitenone B from marine sponge. Suberitenone B, sesterterpenoids of a new skeletal class have been isolated from the sponge Suberites sp. collected from King George Island the Antartic. The structure of the metabolite has been determined by NMR experiments and chemical methods.

• Proceedings of the Korean Society of Potoscience Conference
• /
• 2006.06a
• /
• pp.52-52
• /
• 2006

• Proceedings of the PSK Conference
• /
• 2003.10b
• /
• pp.175.2-175.2
• /
• 2003

Inhibition of the protein-modifying enzyme farnesyltransferase is considered as a major emerging strategy in cancer therapy because of the involvement of farnesylated proteins in oncogensis. We studied the structure-activity relationship of a novel class of CAAX-peptidomimetic farnesyltransferase inhibitors based on the benzophenone scaffold. FlexX docking of inhibitors confirmed reasonable fit of the molecule into the peptide binding site of farnesyltransferase. We also performed a virtual screening with LeadQuest chemical library databases to idenfity novel inhibitors of farnesyltransferase. (omitted)