• Current Research on Agriculture and Life Sciences
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• v.6
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• pp.129-135
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• 1988

The changes of sugar content and invertase activity during maturation of plum fruits, and properties of the enzyme were investigated in this study. The soluble sugars in plum fruits were mainly sucrose, glucose and fructose. The sucrose content in the fruit increased slowly at the early stage of maturation and then decreased slightly. At the final stage, the sucrose content increased remarkably with maturation. The contents of glucose and fructose increased slowly at the early stage of maturation following decrement at middle stage. At the final stage, glucose content decreased continuously while fructose content increased again following decrement. Invertase activity in the fruit increased during maturation showing maximum at the onset of color change and after that, decreased remarkably. The optimum pH and temperature of invertase activity were pH 5.0 and $65^{\circ}C$, respectively. The enzyme was most stable at pH 5.0 and retained 75% of its activity after incubation at $70^{\circ}C$ for 15min. The enzyme was activated by $Cu^{{+}{+}}$, $Ca^{{+}{+}}$, but inhibited by $Hg^{{+}{+}}$ remarkably.

• Journal of the Korean Society of Tobacco Science
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• v.16 no.2
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• pp.144-151
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• 1994

Using a flue-cured tobacco variety, BU 109, effect of growth regulators(Fatty Alcohol and C-MH) on the change of invertase activity and sugar metabolites were investigated. Invertase activity in untreated leaf tissue was decreased along with maturation of leaf, However, a momentary increase of the activity was observed in leaves by the dual treatment of fatty alcohol and C-MH regardless of leaf position while sole C-MH treatment resulted in activity increase by 14 days after the treatment. Similar tendency was observed in stalk. Sugar content in leaf was increased immediately after the treatment but no significant increase at large resulted until 14 days after treatment. After harvest, reducing sugar was increased by the growth regulators. Nevertheless, in case of dual treatment, the total sugar content was not different with that of untreated control. R/T ratio was gradually increased after topping stage and reached maximum at 14 days after treatment of growth regulators. It decreased a little after harvest but the RR ratio was relatively higher due to increase of reducing sugar resulted by the treatment of the chemicals. Upon treatment of growth regulators, reducing sugar content was increased in lugs and leaves compared to untreated control and the content of sugar metabolites was increased by the use of the chemicals either at lower or higher than recommended dose. Key words : MH, FA, invertase activity, total sugar, reducing sugar

• Molecules and Cells
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• v.26 no.3
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• pp.236-242
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• 2008

Invertase (${\beta}$-D-fructofuranosidase; EC 3.2.1.26) catalyzes the conversion of sucrose into glucose and fructose and is involved in an array of important processes, including phloem unloading, carbon partitioning, the response to pathogens, and the control of cell differentiation and development. Its importance may have caused the invertases to evolve into a multigene family whose members are regulated by a variety of different mechanisms, such as pH, sucrose levels, and inhibitor proteins. Although putative invertase inhibitors in the Arabidopsis genome are easy to locate, few studies have been conducted to elucidate their individual functions in vivo in plant growth and development because of their high redundancy. In this study we assessed the functional role of the putative invertase inhibitors in Arabidopsis by generating transgenic plants harboring a putative invertase inhibitor gene under the control of the CaMV35S promoter. A transgenic plant that expressed high levels of the putative invertase inhibitor transcript when grown under normal conditions was chosen for the current study. To our surprise, the stability of the invertase inhibitor transcripts was shown to be down-regulated by the phytohormone ABA (abscisic acid). It is well established that ABA enhances invertase activity in vivo but the underlying mechanisms are still poorly understood. Our results thus suggest that one way ABA regulates invertase activity is by down-regulating its inhibitor.

• Journal of Plant Biology
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• v.35 no.1
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• pp.91-95
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• 1992

Changes of contents of reducing sugar and sucrose and activities of sucrose-phosphate synthase, sucrose synthease and invertase from the leaves of barley (Hordeum vulgare L. cv. Chalssal) seedlings grown at $4^{\circ}C$ were investigated, and the property of acid invertase were also examined. In the seedlings grown at $4^{\circ}C$ for 3 days, the contents of reducing sugar and sucrose were increased to 1.3 and 2.4 times, respectively. Activity of acid invertase was decreased markedly by cold treatment while the activities of sucrosephosphate synthase, sucrose synthase, and alkaline invertase were not changed. In acid phosphatase purified partially by ammonium sulfate fractionation and DEAE-Sephacel column chromatography, the $K_m$ value for sucrose was 9.5 mM and the optimum pH and temperature was 5.5 and $35^{\circ}C$ respectively. This enzyme was supposed to be ${\beta}-fructosidase$ by studies on the substrate specificity and the molecular weight was estimated to be 63 Kd by Sephadex G-200 gel chromatography.graphy.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.74.2-74
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• 2003

Arabidopsis infected with beet curly top virus (BCTV) has the systemic symptoms like stunting of Plant growth, curling of leaves and shoot tips, and callus induction. The regulation of sucrose metabolism by BCTV infection is essential for obtaining the energy source in the process of virus replication and symptom development. Sucrose metabolism-associated gene expression and biochemical enzyme activity were analyzed with the rossette leaves and inflorescencestems of BCTV infected Arabidopsis by the time course of 1, 7, 14, 21 day postinoculation. The expression of invertase and sucrose synthase genes ( encoding sucrose-cleaving enzymes )was increased and reversely the level of Atkin10a ( sucrose non-fermenting gene ) was decreased, resulting by semi-quantitative reverse transcription polymerase chain reaction. The biochemical analysis of invertase and sucrose synthase activity was performed. The activity of neutral invertase in the inflorescence stems was elevated remarkably. The photosynthetic response in the source of sucrose metabolism was consistent with the down-regulation of ribulose 1,5 bisphosphate carboxylase gene, and lower activity than mock-inoculated plants. The levels of genes pertaining to the cell cycle, hormone, and biotic stress-related pathway showed an increase or a decrease dependent on viral symptoms. Therefore, sucrose sensing by BCTV infection can regulate the expression of sucrose metabolism-related key enzymes such as invertase and Atkin10a, and these gene products might influence to symptom development.

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.3
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• pp.706-716
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• 1996

The purpose of this study was to investigate. the effects of the lactation of human or bovine milk and the method of using nursing bottles on the salivary invertase test scores and deciduous caries experience of children. 328 preschool children (boys 178, girls 150) in Iksan city were selected for this study. The parents of the children were asked to answer the questionnaire about the lactation of human or bovine milk and the time of using nursing bottles. The data were obtained from the salvary invertase activity score,(Resazurin Disc Test) deciduous caries experience and the questionnaire. The result were as follows. The invertase activity and caries experience of the human milk higher than that of the bovine milk group(P<0.05). There were significant positive relationships between the lactation period and the invertase activity and between the lactation period and the caries experience(P<0.05). Caries experience had a tendency to increase as the time of using nursing bottles increase (P>0.05).

• Preventive Nutrition and Food Science
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• v.2 no.3
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• pp.250-254
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• 1997

The internal invertase of Rhodosporidium toruloids mating type a cells was purified to a single band on SDS-PAGE from cell-free extract by acid precipitation, ion exchange chromatogaphy andgel filtration. The determined molecular weight of he purified enzyme was about 95,000 by gel filtration and 100,000 daltons on SDS-polyacryamide gel electrophoresis. This enzyme didn't show any activity change by several metal ions except 15.4% decrease by {TEX}$Mn^{2+}${/TEX} and was strongly inhibited by 2-mercaptoethanol and SDS. The invertase maintained its activity at high level until 70℃, but inactivated at 80℃ almost completely. The optimal temperature and pH of the enzyme were about 60℃ and pH 5.0, respectively. The stable pH range of invertase was narrow from pH 3.0 to 6.0. The Km value and isoelectric point of enzyme were 3.4×{TEX}$10^{3}${/TEX} M, pH 4.4, respectively.

• Microbiology and Biotechnology Letters
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• v.17 no.3
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• pp.263-268
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• 1989

To maximize the performance of recombinant cell fermentation process through optimizing environmental conditions, the production of invertase from recombinant Saccharomyces cerebisiae Containing SUC2 gene was studied as a model. The recombinant cells showed biphasic growth on glucose. Since the promoter of the SUC2 is regulated by the concentration of glucose in the medium, expression of invertase by recombinant yeast began when the glucose concentration decreased in a range of 0.25-0.4 g/L during the batch culture. Plasmid segregation occured frequently during glucose fermentation, and infrequently during ethanol oxidation. A rapid appearance of invertase activity with glucose was observed under nonaerated condition, and the maximum specific invertase activity was about 1.5 times as high as under aerobic condition, In fed batch culture, when n low level of glucose was continuously supplied to the tormentor after the time of glucose depletion during growth phase, specific and total invertase activity increased about 1.7 and 2.9 fold, respectively, in a batch culture.

• Journal of the Korean Society of Food Culture
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• v.5 no.2
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• pp.269-274
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• 1990

This study was conducted to determine invertase activity in persimmon during the drying process and characterize the purified enzyme. As drying proceeded, invertase activity increased until 10 days and decreased gradually afterwards. Invertase in persimmon fruit was extracted with 250 mM potassium phosphate sulfate buffer at pH 7.4. The enzyme was purified by means of ammonium sulfate fractionation, column chromatography on DEAE-cellulose and gel filtration on Sephadex G-200 column. The optimal temperature of enzyme was $40^{\circ}C$ and optimal pH was 5.0 and 6.0 for sucrose and raffinose, respectively. The enzyme was stable up to $50^{\circ}C$ and pH 3-6. The Km value of the enzyme, with sucrose as a substrate, was 2.5mM. Electrophoretic pattern of purified enzyme solution showed a single band.

• Microbiology and Biotechnology Letters
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• v.18 no.4
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• pp.368-375
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• 1990

Rhodoto& ghtbth~ K-24 was found to produce external invertase in addition to internal and cell wall bound invertase. External invertase was purified to an electrophoretically homogeneous state and partitally characterized and was compared with internal and cell wall bound invertase of which procedures for purification and characterization were reported previously. The enzyme was purified by ethanol precipitation, column chromatographies on DEAE-Sephadex A-50 and SP-Sephadex C-50, and gel filtration on Sephadex G-100. The molecular weight and subunit molecular weight of external invertasGwere estimated to be 220,000 and 100,000, respectively. The isoelectric point of the enzyme was about pH 6.0. The optimum pH and temperature for enzyme activity were pH 4.0 and $60^{\circ}C$, respectively. The enzyme remained stable at the wide range, from pH 3.0 to 11.0 and stable up to $40^{\circ}C$, but was inactivated at temperatures above that. $HgC_12, AgN0_3, MnS0_4$, SDS and p-CMB inhibited the enzyme activity. The $K_m$ value of the enzyme for sucrose was $1.0\times 10^{-2}$M. From these results, the three isozymes from Rh. glutinis K-24 seem to have the similar enzymatic properties, but to differ in molecular and subunit weights.