Publications by authors named "P J Maeng"

The transgalactosylase activity of β-galactosidase produces galacto-oligosaccharides (GOSs) with prebiotic effects similar to those of major oligosaccharides in human milk. β-Galactosidases from ATCC 31382 are important enzymes in industrial-scale GOS production. Here, we show the high GOS yield of β-galactosidase II from (β-Gal-II, Lactazyme-B), compared to other commercial enzymes.

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Multiple transcriptional regulators play important roles in the coordination of developmental processes, including asexual and sexual development, and secondary metabolism in the filamentous fungus Aspergillus nidulans. In the present study, we characterized a novel putative CH-type transcription factor (TF), RocA, in relation to development and secondary metabolism. Deletion of rocA increased conidiation and caused defective sexual development.

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The yeast Saccharomyces cerevisiae has two isoforms of NADP-dependent glutamate dehydrogenase (Gdh1 and Gdh3) that catalyze the synthesis of glutamate from α-ketoglutarate and NH. In the present study, we confirmed that Gdh3, but not Gdh1, mainly contributes to the oxidative stress resistance of stationary-phase cells and found evidence suggesting that the insignificance of Gdh1 to stress resistance is possibly resulted from conditional and reversible aggregation of Gdh1 into punctuate foci initiated in parallel with post-diauxic growth. Altered localization to the mitochondria or peroxisomes prevented Gdh1, which was originally localized in the cytoplasm, from stationary phase-specific aggregation, suggesting that some cytosolic factors are involved in the process of Gdh1 aggregation.

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Recently there has been a growing interest in three-dimensional (3D) cell culture systems for drug discovery and development. These 3D culture systems better represent the in vivo cellular environment compared to two-dimensional (2D) cell culture, thereby providing more physiologically reliable information on drug screening and testing. Here we present the quantitative profiling of a drug-induced proteome in 2D- and 3D-cultured colorectal cancer SW480 cells using 2D nanoflow liquid chromatography-tandem mass spectrometry (2D-nLC-MS/MS) integrated with isobaric tags for relative and absolute quantitation (iTRAQ).

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