• 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.

• Microbiology and Biotechnology Letters
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• v.17 no.4
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• pp.313-320
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• 1989

Rhodotorula glutinis K-24 was found to produce internal, cell wall bound, and external invertase. Internal invertase was purified by column chromatographies on DEAE-Sephadex A-50, Sp-sephadex C-50, gel filtration on Sephadex G-200 and isoelectric focusing. Cell wall bound invertase was partially purified by the following procedures; column chromatography on DEAE-Sephadex A-50 and gel filtration on Sephadex G-100. Optimum pH and temperature for enzymatic activities of internal and cell wall bound invertase were pH 3.0 and 6$0^{\circ}C$, respectively. Both enzymes were inhibited by HgC1$_2$, AgNO$_3$, MnSO$_4$, and sodium dodecylsulfate. The molecular weights of internal and cell wall bound invertases were estimated to be 310,000 and 61,000, respectively. Other physicochemical properties of the both enzymes were similar.

• Microbiology and Biotechnology Letters
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• v.20 no.6
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• pp.625-629
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• 1992

This work was carried out to study physiological characteristics of Rhodosporidium toru[oides cells having two different mating types. The mating type A produces internal. cell wall-bound, and external invertases while type a produces only two invertases except external invertase. Comparing their characteristics after partial purification of internal invertases from both mating type cells, invertase from type a has decreased 15% of invertase activity only by $Mn^{2+}$ I while invertase from type A has been increased 11% of invertase activity by $Zn^{2+}$ and decreased 15% of invertase activity by $Mn^{2+}$ On the effect of enzyme inhibitor, invertase of type a was inhibited from 12% to 57% by 2-mercaptoethanol, sodium dodecyl sulfate, phenol. but invertase of type A was slightly inhibited only by phenol. The thermal stability of both invertases has showed steep inactivation at above $80^{\circ}C$ and their optimal temperatures were similar at $60^{\circ}C$ . Invertase from type A showed stability only on condition of acid from pH 3 to 6 and its opimal pH was 5.0, while invertase from type a showed stability at the wide range of pH 3-10 and its optimal pH was 4.0. And the $K_m$ values of invertases from type A and type a were $2.5{\times}10^3$M and$3.4{\times}10^3$M, respectively.

• Proceedings of the Korean Society of Potoscience Conference
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• 2006.06a
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• pp.59-59
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• 2006

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2003.04a
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• pp.146-146
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• 2003