• Molecules and Cells
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• v.40 no.5
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• pp.355-362
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• 2017

The ${\beta}2$ integrins are cell surface transmembrane proteins regulating leukocyte functions, such as adhesion and migration. Two members of ${\beta}2$ integrin, ${\alpha}M{\beta}2$ and ${\alpha}X{\beta}2$, share the leukocyte distribution profile and integrin ${\alpha}X{\beta}2$ is involved in antigen presentation in dendritic cells and transendothelial migration of monocytes and macrophages to atherosclerotic lesions. ${\underline{R}}eceptor$ for ${\underline{a}}dvanced$ ${\underline{g}}lycation$ ${\underline{e}}nd$ ${\underline{p}}roducts$ (RAGE), a member of cell adhesion molecules, plays an important role in chronic inflammation and atherosclerosis. Although RAGE and ${\alpha}X{\beta}2$ play an important role in inflammatory response and the pathogenesis of atherosclerosis, the nature of their interaction and structure involved in the binding remain poorly defined. In this study, using I-domain as a ligand binding motif of ${\alpha}X{\beta}2$, we characterize the binding nature and the interacting moieties of ${\alpha}X$ I-domain and RAGE. Their binding requires divalent cations ($Mg^{2+}$ and $Mn^{2+}$) and shows an affinity on the sub-micro molar level: the dissociation constant of ${\alpha}X$ I-domains binding to RAGE being $0.49{\mu}M$. Furthermore, the ${\alpha}X$ I-domains recognize the V-domain, but not the C1 and C2-domains of RAGE. The acidic amino acid substitutions on the ligand binding site of ${\alpha}X$ I-domain significantly reduce the I-domain binding activity to soluble RAGE and the alanine substitutions of basic amino acids on the flat surface of the V-domain prevent the V-domain binding to ${\alpha}X$ I-domain. In conclusion, the main mechanism of ${\alpha}X$ I-domain binding to RAGE is a charge interaction, in which the acidic moieties of ${\alpha}X$ I-domains, including E244, and D249, recognize the basic residues on the RAGE V-domain encompassing K39, K43, K44, R104, and K107.

• Korean Journal of Food Science and Technology
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• v.42 no.2
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• pp.198-203
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• 2010

Although barley $\alpha$-amylase isozyme 1 (AMY1) and 2 (AMY2) share up to 80% of amino acid sequence identity, their enzymatic properties differ remarkably. In this study, the 42nd alanine residue of AMY2 was replaced with another random amino acid via saturation mutagenesis. Eight out of 370 recombinant E. coli cells showing enhanced starch-hydrolyzing activity were characterized as possessing the same proline residue instead of alanine. Even though the specific activity of AMY2-A42P is reduced to 81% of wild-type, its expression level and purification yield were enhanced by approximately 2 and 4 times that of AMY2, respectively. Characterization of its enzymatic properties confirmed that AMY2-A42P is similar to that of wild-type. However, its specificity to starch substrates is likely to be intermediate between AMY1 and AMY2.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.14
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• pp.165-172
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• 1973

The sterile phenomenon is frequently found in the inter-species hybrids of ginseng as in other plants. It is known that among the hybrids between Panax Ginseng (PG) and Panax Quinquefolium (PQ), and between Panax Ginseng and Paxax Japonicus (PI), PG${\times}$PI is fertile only very rarely, while PG ${\times}$ PQ is always sterile. Therefore, in order to clarify the relationship between this sterility phenomenon and the metabolism of free amino acids, the changes of free amino acids through the formation of the flower organs and seeds of two hybrids, PG ${\times}$ PQ and PG ${\times}$ PI were investigated by thin layer chromatography. The results are summarized as follows: 1. Distinct differences in the quantity and number of free amino acids were recognized between PG ${\times}$ PQ, PG ${\times}$ PI and their parent plants. From the hybrid PG ${\times}$ PQ, 19 kinds of ninhyrin sensitive substances were detected in all. They were (1) 17 amino acids: alanine, valine, leucine, phenylalanine, proline, hydroxy-proline, serine, threonine, tyrosine, aspartic acid, glutamic acid, lysine, arginine, ${\gamma}$-amino butyric acid, ${\beta}$-alanine, cysteic acid and tryptophan, and (2) two amides: asparagine and glutamine. From the hybrid PG ${\times}$ PI, in addition to the above 19 substances, methionine and one unknown substance were detected. 2. Generally, alanine, as partie acid, glutamic acid, cysteic acid and asparagine were detected in large amounts in the two hybrids as in PG, PG and PJ but it was a noticeable fact concerning these two hybrids that the largest quantity of asparagine was found at microspore satge and pollen mature stage. 3. The decrease of cysteic acid in the two hybrids at the red ripened stage was the same as in PQ and PJ but opposite to the change in PG. The detection of methionine in PG ${\times}$ PJ was worthy of notice. 4. The change of proline was conspicuously different from that in their parent plants. It was detected as a trace of color at the micros pore stage while asparagine was detected in the greatest amount at that time. It is well known that the quantity of proline is closely related to the sterility of plant. This fact was also found true in the formation of ginseng seeds. It was reported as well that asparagine accumulated when proline decreased. 5. The deficiency of proline seemed to be closely related with the sterility of hybrids and with the degradation of pollen in anther. 6. The difference in the changes of free amino acids between the selfed lines of PG, PQ and PJ, and their hybrids seemed to be caused by the transformation of gene-action system by hybridization. On these phenomena along with proline metabolim and its physiological role in seed formation further studies are required.

• Proceedings of the Korean Society of Life Science Conference
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• 2005.09a
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• pp.73-73
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• 2005

• The Korean Journal of Food And Nutrition
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• v.1 no.2
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• pp.50-55
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• 1988

B-Amylase was obtained from sweet potato extract in a crystalline state by dialysis against water after precipitated with acetone according to the method reported previously followed by DEAE Sephadex A-50 ion exchange chromatography plus gel chromatography of Sephadex G-200. The purified enzyme was homogeneous by SDS PAGE. The efforts had done to remove the miner bands in SDS PAGE by Sephadex G-200 gel chromatography, DATE Sephadex A-50 ion exchange chromatography. isoelectrophocusing, affinity chromatography, hydroxyapatite chromatography, recrystallizstion and HPLC on a column of TSK gel SW 3000 but have given any result. But, N -terminal amino acid of the enzyme was revealed mainly alanine and trace of glycine and glutamic acid. Therefore, it seems that the miner bands in SDS PAGE have a role of subunit.

• Journal of Veterinary Clinics
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• v.8 no.1
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• pp.31-45
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• 1991

Present experiment was performed in order to establish the optimal reaction conditions for determination of urinary AAP and GRS activities and to investigate the applicability of urinary AAP and GRS in nephrotoxicity test in rat. The results were as follows ; 1. The optimal pH of phosphate buffer for determination of urinary AAP activity was 7.8. 2. The Michaelis constant of urinary AAP ranged from 0.8 to 1.0mmol/$\ell$ 3. The optimal wave length for determination of urinary GRS activity was 405nm. 4. The optimal pH of acetate buffer for determination of urinary GRS activity was 5.6. 5. The Michaelis constant of urinary GRS ranged from 0.65~0.79mmo1/$\ell$. 6. The AAP activities in gel-filtered samples were significantly higher than those in crude samples. Mean values of AAP activities in gel-filtered samples and crude samples were 29$\pm$20 and 20$\pm$13U/$\ell$, respectively. 7. There was not significant difference between gel-filtered samples and crude samples in urinary GRS activities. Mean values of GRS activities in gel-filtered samples and crude samples were 57$\pm$40 and 56$\pm$39U/$\ell$, respectively. 8. Limits of linearity of urinary AAP and GRS activities were 2.0 and 3.6U/$\ell$, respectively. 9. Within-run imprecisions of the assays, were acceptable, as the coefficients of the AAP activities ranged from 5.5 to 6.3% and those of GRS activities ranged from 1.4 to 6.2%, respectively. 10. Urinary AAP excretion was 675$\pm$227mu/24hrs.kg before administration of potassium dichromate, and increased significantly to 4246$\pm$2567mU/24hrs.kg within 24 hours after administration of potassium dichromate. 11. Urinary GRS excretion did not increase significantly after administration of potassim dichromate. 12. From these findings it is concluded that urinary AAP excretion is early and sensitive Indicator to detect kidney damage in nephrotoxicity experiment.

• BMB Reports
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• v.32 no.4
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• pp.370-378
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• 1999

The effects of carnosine and related compounds (CRC) including anserine, homocarnosine, histidine, and ${\beta}$-alanine, found in most mammalian tissues, were investigated on in vitro glucose oxidation and glycation of human serum albumin (HSA). Carnosin and anserine were more reactive with D-glucose than with L-lysine. In the presence of $10\;{\mu}M$ Cu (II), although carnosine and anserine at low concentrations effectively inhibited formation of ${\alpha}$-ketoaldehyde from D-glucose, they increased generation of $H_2O_2$ in a dose-dependent manner. Carnosine, homocarnosine, anserine, and histidine effectively inhibited hydroxylation of salicylate and deoxyribose degradation in the presence of glucose and $10\;{\mu}M$ Cu (II). In the presence of 25 mM D-glucose, copper and ascorbic acid stimulated carbonyl formation from HSA. Except for ${\beta}$-alanine, CRC effectively inhibited the copper-catalyzed carbonyl formation from HSA. The addition of 25 mM D-glucose and/or $10\;{\mu}M$ Cu (II) to low density lipoprotein (LDL) increased formation of conjugated dienes. CRC effectively inhibited the glucose and/or copper-catalyzed LDL oxidation. CRC also inhibited glycation of HSA as determined by hydroxymethyl furfural and lysine with free ${\varepsilon}$-amino group. These results suggest that CRC may play an important role in protecting against diabetic complications by reacting with sugars, chelating copper, and scavenging free radicals.

• Toxicological Research
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• v.14 no.3
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• pp.365-370
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• 1998

To evaluate the renal toxicity of the antitumor agent, p-{N,N,-Bis(2-chloroethyl)amino}-4-phenyl acetyl-amino-2,6-piperidinedione(CK-15), rats were treated with CK-15 (acute: 50mg/kg. i.p., single and subacute: 5mg/kg, i.p., daily for 7 days). The changes in the body weight, water consumption, kidney weights and urine volume after and during the treatment were observed. The concentrations of urinary creatinine and portein, the activities of N-acetyl-${\beta}$-D-glucosaminidase (NAG), alanine aminopeptidase (AAP), ${\gamma}$-glutamyl transpeptidase (${\gamma}$-GT) and lactate dehydrogenase (LDH) in 24hr urine were also determined. The body weight, water consumption, and urine volume were decreased after the acute and subacute administration. However the weights of kidney were not changed after the treatments. The excretion of creatinine was significantly decreased 1 day after acute administration but, returned to the control value. In subactute administration, the excretion of creatinine was gradually decreased. However, the protein excretion did not changed in both treatment. Those indicate that CK-15 might decrease the metabolic rate of muscle. THe urinary activities of NAG, AAP, ${\gamma}$-GT, and LDH were significantly affected bythe drug treatment. The urinary activities of NAG, AAP and ${\gamma}$-GT were significantly increased 1 day after the acute administration and then returned to the control value. However, the urinary activities of LDH were not changed in acute treatment. In subacute treatment, although the urinary activities of NAG were not changed, those of AAP and ${\gamma}$-GT were significantly increased 2.3 times at 3 days during the subacute administration. Also the urinary activities of LDH were significantly increased at 7 day after the administration. These results indicate that the high and subacute administration might induce a damage in the kidney cells. Furthermore the present results suggest that the toxic effects of CK-15 might be due to the accumulation of the metabolites.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.2
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• pp.141-146
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• 1986

As a fundamental study of fresh water fish on a suitable cooking method and on flavor components from the view point of food science, changes in the free amino acid composition of the muscle extracts of snakehead (Channa argus) during heating in boiling water were investigated. The muscle extract of raw fish was featured a very high content of glycine, taurine, glutamic acid and histidine, and a large amount of urine was also determined in the extract; the former four components comprised about $53\%$ of the total free amino acids. The total extractable nitrogen was greatly increased with the heating time till 120 minutes of heating, while it gradually decreased thereafter. The apparently increased components on heating of 120 minutes were taurine, glycine, alanine, hydroxyproline, and ${\beta}$-aminoisobutyric acid, etc. including urea. After hydrolysis of the extracts, some of the amino acids were increased, the content of ethanolamine, lysine, 1-methyl histidine, phenylalanine, glutamic acid and taurine, etc. were apparently increased.

• Journal of the Korean Chemical Society
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• v.33 no.4
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• pp.343-349
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• 1989

The dissociation constants of ${\beta}$-alanine and ${\gamma}$-aminobutyric acid were measured in the temperature range from 20 to $40^{\circ}C$ and pressure up to 2,500 bar by conductometric method. The both dissociation constants of respective amino acid increase with temperature increase but pressure effect is not same as the temperature. The $K_1$ increases as pressure increases but $K_2$ decreases. The properties of these amino acids were discussed in terms of the thermodynamic properties of the dissociation reaction. A relationship between the dissociation constants and the distance between substituted groups of amino acid was discussed. The substituted effects of the reaction were deduced from Hammett reaction and substituted constants which were calculated from the measured dissociation constants.