Daohai Zhang

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Isomaltulose synthase from Klebsiella sp. LX3 (PalI, EC 5.4.99.11) catalyzes the isomerization of sucrose to produce isomaltulose (alpha-D-glucosylpyranosyl-1,6-D-fructofuranose) and trehalulose (alpha-D-glucosylpyranosyl-1,1-d-fructofuranose). The PalI structure, solved at 2.2-A resolution with an R-factor of 19.4% and Rfree of 24.2%, consists of three(More)
The gene (palI) encoding isomaltulose synthase (PalI) from a soil bacterial isolate, Klebsiella sp. strain LX3, was cloned and characterized. PalI converts sucrose into isomaltulose, trehalulose, and trace amounts of glucose and fructose. Sequence domain analysis showed that PalI contains an alpha-amylase domain and (beta/alpha)(8)-barrel structures,(More)
Tissue microarrays allow high throughput molecular profiling of diagnostic or predictive markers in cancer specimens and rapid validation of novel potential candidates identified from genomic and proteomic analyses in a large number of tumor samples. To validate the use of tissue microarray technology for all the main biomarkers routinely used to decide(More)
The receptor tyrosine kinase ErbB2 (HER-2/neu) is overexpressed in up to 30% of breast cancers and is associated with poor prognosis and an increased likelihood of metastasis especially in node-positive tumors. In this proteomic study, to identify the proteins that are associated with the aggressive phenotype of HER-2/neu-positive breast cancer, tumor cells(More)
The epithelial-mesenchymal transition (EMT) is a key step for cancer cell migration, invasion, and metastasis. Transforming growth factor-β (TGF-β) regulates the EMT and the metastasis suppressor gene, N-myc downstream-regulated gene-1 (NDRG1), could play a role in regulating the TGF-β pathway. NDRG1 expression is markedly increased after chelator-mediated(More)
Isomaltulose synthase (PalI) catalyzes hydrolysis of sucrose and formation of alpha-1,6 and alpha-1,1 bonds to produce isomaltulose (alpha-D-glucosylpyranosyl-1,6-D-fructofranose) and small amount of trehalulose (alpha-D-glucosylpyranosyl-1,1-D-fructofranose). A potential isomaltulose synthase-specific motif ((325)RLDRD(329)), that contains a 'DxD' motif(More)
Cells of strain LX3(T), isolated from soil, were Gram-negative, facultatively anaerobic, non-motile, capsulated and non-endospore-forming straight rods, able to grow at 10 degrees C, unable to produce gas from lactose at 45 degrees C and unable to produce indole. The isolate converted sucrose to isomaltulose and did not produce detectable glucose(More)
The metastasis suppressor, N-myc downstream regulated gene-1 (NDRG1), has been shown to markedly reduce metastasis of numerous tumors. The current study was focused on further elucidating the molecular mechanisms behind the antitumor function of NDRG1. We have identified for the first time that NDRG1 upregulates the potent cyclin-dependent kinase inhibitor,(More)
Endoplasmic reticulum protein 29 (ERp29) is a novel endoplasmic reticulum (ER) secretion factor that facilitates the transport of secretory proteins in the early secretory pathway. Recently, it was found to be overexpressed in several cancers; however, little is known regarding its function in breast cancer progression. In this study, we show that the(More)
Cytokeratin 19 (CK19) is widely used as a biomarker for the detection of disseminated tumor cells in blood and bone marrow, and its positivity is considered as an independent prognostication indicator in cancer patients. However, its role in breast cancer progression remains unknown. We had established a stable CK19-expressing clone in the CK19-negative(More)