• Applied Biological Chemistry
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• v.50 no.2
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• pp.127-131
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• 2007

The molecular design and holographic (H) quantitative structure-activity relationships (HQSARs) on the binding affinity constants between new 3-benzylidenemyosmine analogues and nicotin acetylcholine receptors (nAChRs) of American cockroach (Periplaneta. americana L.) were studied quantitatively. The optimized HQSAR model (IV-2) for the binding affinity constants was derived from fragment distinction of hydrogene atoms in fragment size, 5${\sim}$8 bin. The statistical results of the HQSAR model (IVI-2) exhibited the best predictability and fitness for the binding affinity constants based on the cross-validated value (q$^2$=0.507) and non cross-validated value (r$^2_{nev.}$=0.944). From the graphical analyses of atomic contribution maps, it was revealed that the binding affinity constants depends upon the anabaseine ring in molecule and the most active compounds were designed by optimized HQSAR model (VI-2).

• Reproductive and Developmental Biology
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• v.31 no.1
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• pp.15-20
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• 2007

To search of a new porcine pheromonal odorant for biostimulation control system technologies to offer a potentially useful and practical way to improve reproductive efficiency in livestock species, the two dimensional quantitative structure-activity relationship (QSAR) models between physicochemical parameters as descriptors of 2-cyclohexyloxytetrahydrofurane (A), 2-phenoxytetrahydrofurane (B) analogues and binding affinity constant ($p[Od.]_{50}$) for porcine odorant-binding protein (pOBP) as receptor of pig pheromones were derived and disscused. The statistical quality of the optimized 2D-QSAR model is good ($r^{2}=0.964$) and accounts for 96.4% of the variance in the binding affinity constants. It was found that the binding affinity constants were dependent upon the optimal value, $(SL)_{opt.}=1.418$ of substituent lipole (SL) in molecules. Therefore, the SL constant was very important factor for binding affinity.

• Korean Journal of Animal Reproduction
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• v.18 no.2
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• pp.95-99
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• 1994

The purpose of the present study was to determine the in vivo effect of oxytocin antagonist-I(Al) on uterine oxytocin receptor number (Rn) and/or binding affinity (Kd) in the estrous rat. Anesthetized rats were given a bolus infusion of control or 5${\mu}\textrm{g}$ of AI and sacri-ficed 0.5 and 4 hours later. The uterine tissue was removed, trimmed and frozen. Membrane oxytocin receptors were isolated after homogenization of uterine tissue and differential ultracentrifugation. The oxytocin receptor assay was performed by saturation with cold oxytocin competion with a high specific activity oxytocin antagonist. Rn and Kds were determined by nonlinear curve fitting methods. No differences(p>0.05) between the AI and control treated animals in either oxytocin receptor number or binding affinity was detected in this study. These data suggest that the major mode of action of AI is via competitive inhibition at the uterine oxytocin receptor and not by altering receptor number or binding affinity.

• The Korean Journal of Pesticide Science
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• v.9 no.1
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• pp.88-96
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• 2005

Paraquat-resistant biotype of Conyza canadensis (L.) Cronq. was determined by chlorophyll loss and random amplified polymorphic DNA (RAPD) analysis and the resistant mechanism was investigated with respect to absorption, translocation, and binding constant. RAPD analysis for paraquat resistant (R) and susceptible (S) biotypes found in a pear orchard revealed that the biotypes possessed remote genetic relationship. Chlorophyll loss, as an indication of paraquat toxicity, of S biotype was 7.8-fold greater than that of R biotype. There were no differences in contents of epicuticular wax and cuticle and amounts of [14C]paraquat penetrating the cuticle between the two biotypes. Little translocation of the herbicide out of the treated leaf was observed in either biotype. Binding constants of paraquat to the cell wall and thylakoid membrane were 7.4-fold and 16.9-fold, respectively, higher in R biotype than in S biotype. The results suggest that the resistance mechanism of C. canadensis biotype is due partly to high binding affinity of paraquat to the cell wall and thylakoid membrane.

• KSBB Journal
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• v.7 no.3
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• pp.201-208
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• 1992

Cell surface binding of epidermal growth factor(EGF) to EGF receptors was studied for a series of site-directed receptor mutants transfected into B82 mouse fibroblasts. Scatchard plots for truncation mutant receptors significantly lost nonlinearity for truncations below residue 1022. Transient plots of dissociation kinetics exhibited biphasic behavior for all receptor types, but the fraction of receptor in slow-dissociating form was reduced by an order of magnitude for the truncation mutants below residue 1022. Comparison of dissociation kinetics between control cells and cells treated with Triton X-100 revealed no significant variation for the slow-dissociating receptor form, but a noticeable variation was observed for the fast-dissociating receptor form when EGF receptors were truncated below residue 991. These results suggest that high affinity of EGF binding at cell surface depend on the EGF receptor cytoplasmic region.

• Reproductive and Developmental Biology
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• v.29 no.1
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• pp.43-48
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• 2005

To search of a new porcine pheromonal odorants for biostimulation control system technologies to offer a potentially useful and practical way to improve reproductive efficiency in livestock species, the holographic quantitative structure activity relationship (HQSAR) model between odorants, 2-phenoxytetrahydrofurane (A), 2-cyclohexyl-oxytetrahydrofurane (B), derivatives and binding affinity constants (p[Od.]/sub 50/) for porcine odorant-binding protein (pOBP) as receptor of pig pheromones were derivated and disscused. The binding affinity constants of cyclohexyl substituents (A) for pOBP were higher (A>B) than that of phenyl substituents (B). It was revealed that the optimum HQSAR model XI using PLS analyses had a fragment length (5∼8) with chirality at 5 components and hologram length 97 bin, which had a cross-validated q²(predictablities) of 0.916, and a conventional correlation coefficient r² (fitness) of 0.988, respectively. From the atomic contribution, the C3 and C5 atom in 2-oxyfuryl group contributed to binding affinity constants, whereas the central carbon atom in tert-butyl group on the cyclohexyl ring and the C4 atom of furyl group parts showed no contribution.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.233-233
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• 1994

인삼 성분이 학습 및 기억력 중진에 미치는 효과를 연구하기 위하여, 학습 및 기억력 저하를 유발하는 약물들에 대한 아답타겐 (상품명) 과 인삼 수 엑기스산의 효과를 관찰하였다. Ethylcholine aziridium ion(AF64A), scopolamine 및 morphine을 쥐 및 생쥐의 해마와 복강에 각 각 주입하여 학습 및 기억력 저하를 유발한 후 아답타겐을 경구 투여하여 학습 및 기억력에 미치는 효과를 수로시험을 통하여 측정하였다. 또한 인삼 수 엑기스산을 일주일 동안 복강 주사하여 각 효과를 수로시험을 통하여 측정하였다. 또한 인삼 수 엑기스산을 일주일동안 복강 주사하여 각종 신경계에 미치는 변화를 효소 활성도, 신경전달물질의 농도, 수용체 결합을 지표로 하여 살펴보았다. AF64A 투여군 중 플랫폼을 전혀 인지치 못한 군에 아답타겐을 투여시에는 투여 횟수에 따라 플랫폼을 인지하는 비율이 증가했다. 연습 후 일주일간 물을 투여한 대조군의 도달 시간에 큰 변화가 없음에 반해, 아답타겐을 투여시에는 3일 투여 후 최대 시간이 걸리고, 투여횟수가 증가할수록 점차 도달 시간이 단축되었다. 인공 뇌척수액 및 AF64A의 투여군에서 아답타겐을 5일간 투여한 경우 대조군보다 각각 3배 빠른 속도로 플랫폼을 기억하였다. 한편 scopola mine 투여시에는 아답타겐을 투여한 군이 투여하지 않은 군보다 약 3배 빨리 플랫폼에 도달하였으나 각 투여군의 매일의 도달 시간 차이에는 변화를 나타내지 않았다. 또한 4일 전에 아답타겐을 투여시에는 saline 및 merphine 투여시 약 1.4배 빨리 플랫폼을 인지하였다. 인삼 추출물을 7일 투여 했을 경우 선조체에서 도파민 합성 효소인 tyrosine hydroxylase 활성이 유의성 있게 증가했으며, 대사체인 DOPAC의 농도도 증가를 나타냈다. 그러나, 도파민, HVA및 대사율인 DOPAC/DA와 HVA/DA에는 변화를 보이지 않았다. 또한 선조체의 GABA농도는 약 66%로 낮아졌지만 AChE의 활성도는 변화가 없었다. 인삼 수 추출물을 2주일 투여시 선조체의 도파민 수용체의 특성변화는, D1 수용체의 친화력에는 변화가 없는 반면, 최대 결합 수용체 수는 약간 낮아졌고, D2 수용체의 경우 최대 결합 수용체수는 변화가 없었으나 친화력은 감소하였다. 또한 피질의 benzodiazipine수용체 결합 친화력에는 변화가 없는 반면 최대 결합 수용체 수는 약 15%의 증가를 나타내었고 연수의 benzodiazepine 및 피질의 GABA 수용체의 특성에는 에는 변화를 나타내지 않았다. 이상의 결과, AF64A, 아급성 scopolamine 및 급성 morphine꽈 투여로 학습능이 저하되고 아답타겐을 경구 투여시엔 저하된 학습능력 빛 기억력의 증가를 보였다. 또한 본 결과는 인삼성분 중에는 도파민 및 GABA신경계에 영향을 주는 성분이 있음을 제시하였다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.10 no.1
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• pp.67-76
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• 1981

By using the paper chromatograph technique affinity of amino acids to the mercury was compared with that of sodium thiosulfate, 2,3-dimercaptopropanol(BAL) and inosinic acid. Among the amino acids of testment three acids (Cysteine, Cystine and Methionine) which posses sulfide or disulfide radical exhibited a spot which combined more apparently with the mercury than other amino acids. However, in the mixed solutions of thiosulfate, BAL or inosinic acid with those amino acid and mercury, the mercury was moved into thiosulfate, BAL or inosinic acid spot. It was clear from the results that affinity of sodiume thiosulfate, BAL and inosinic acid to the mercury is higher than that of amino acids.

• Journal of Life Science
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• v.17 no.2 s.82
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• pp.204-210
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• 2007

Previous reports indicated that the carboxyl terminal residues, glutamine276-threonine277 in particular, were important for actin affinity of the unacetylated smooth ${\alpha}-tropomyosin$. To determine the role of the glutamine and threonine residues in C-terminal region in actin binding, we constructed mutant striated muscle ${\alpha}-tropomyosin$ (TMs), in which these two residues were individually substituted. These mutant tropomyosins, designated TM18 (HT) and TM19 (QA), were overexpressed in E. coli as an either unacetylated form or Ala-Ser. (AS) dipeptide fusion form, and were analyzed F-actin affinity by cosedimentation. Unacetylated TM19 (QA) bound to actin approximately three times stronger than TM18 (HT) and much stronger than ST (HA). AS/TM19 (QA) showed four times stronger, in actin affinity than AS/ST (HA) while AS/TM14 (QT) bound to actin stronger to some extent than AS/TM18 (HT). These results suggested that the presence of Gln residue at 276 be primarily attributed to higher actin affinity of smooth ${\alpha}-tropomyosin$.

• Reproductive and Developmental Biology
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• v.30 no.1
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• pp.13-19
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• 2006

To search of new porcine pheromonal odorants for biostimulation control system technologies to improve reproductive efficiency in livestock species, the comparative molecular field analysis (CoMFA) for binding affinity constant $(p(Od)_{50})$ between porcine odorant binding protein (pOBP) and ligands of odorant 2-(cyclohexyloxy) tetrahydrofurane derivatives as substrate molecule was conducted and discussed. In the optimized CoMFA model AIV with chirality $(C_1'(R),\;C_2(S))$ in substrate molecule and atom based fit alignment (A) of odorants, the statistical results showed the best predictability of the binding affinities $(p(Od)_{50})$ based on the LOO cross-validated value $r^2_{cv}.\;(q^2=0.886)$ and non-cross-validated conventional coefficient $(r^2_{ncv}.=0.984)$. the binding affinity constants exhibited a good correlation with steric (40.8%), electrostatic (14.6%) and hydrophobic (44.6%) factors of the substrate molecules. from the analytical results of the contour maps, which may give us some valuable informations to the modification of odorants for effective binding affinity.