Enzymatic characterization of recombinant rat DDHD2, a soluble diacylglycerol lipase

学位記番号：医博甲1589

Escherichia coli Cytosolic Glycerophosphodiester Phosphodiesterase (UgpQ) Requires Mg2+, Co2+, or Mn2+ for Its Enzyme Activity▿

Escherichia coli cytosolic glycerophosphodiester phosphodiesterase, UgpQ, functions in the absence of other proteins encoded by the ugp operon and requires Mg2+, Mn2+, or Co2+, in contrast to Ca2+-dependent periplasmic glycerophosphodiester phosphodiesterase, GlpQ. UgpQ has broad substrate specificity toward various glycerophosphodiesters, producing sn-glycerol-3-phosphate and the corresponding alcohols. UgpQ accumulates under conditions of phosphate starvation, suggesting that it allows the utilization of glycerophosphodiesters as a source of phosphate. These results clarify how E. coli utilizes glycerophosphodiesters using two homologous enzymes, UgpQ and GlpQ

Synthesis, Inhibitory Effects on Nitric Oxide and Structure-Activity Relationships of a Glycosphingolipid from the Marine Sponge Aplysinella rhax and Its Analogues

The novel glycosphingolipid, b-D-GalNAcp(1®4)[a-D-Fucp(1®3)]-b-D-GlcNAcp(1®)Cer (A), isolated from the marine sponge Aplysinella rhax has a unique structure, with D-fucose and N-acetyl-D-galactosamine moieties attached to a reducing-end N-acetyl-D-glucosamine through an a1®3 and b1®4 linkage, respectively. We synthesized glycolipid 1 and some non-natural di- and trisaccharide analogues 2-6 containing a D-fucose residue. Among these compounds, the natural type showed the most potent nitric oxide (NO) production inhibitory activity against LPS-induced J774.1 cells. Our results indicate that both the presence of a D-Fuca1-3GlcNAc-linkage and the ceramide aglycon portion are crucial for optimal NO inhibition

Hypoxic Preconditioning Enhances Angiogenic Potential of Bone Marrow Cells With Aging-Related Functional Impairment

Background: Hypoxic preconditioning of bone marrow cells (BMCs) from young healthy individuals can enhance the cells\u27 therapeutic potential. Considering that the response to hypoxia may differ according to the quality of the cells, we assessed the effect of hypoxic preconditioning on BMCs from aged mice and compared the difference in response between BMCs from aged and young mice. Methods and Results: BMCs from young (3 months) and aged (20-22 months) mice were subjected to hypoxic preconditioning by culture for 24 h in 2% O2. Compared with BMCs from young mice, those from aged mice showed significantly fewer CD34- or c-kit-positive stem cells, higher expression of p53, and lower telomerase activity. Adhesion, survival and angiogenic potency were also lower in BMCs from aged mice, indicating an aging-related impairment. Hypoxia-preconditioned BMCs from aged mice showed enhanced adhesion, survival, and angiogenic potency with the in vitro assessments, as well as the in vivo implantation into ischemic hindlimbs. All the enhancements by hypoxic preconditioning were comparable between BMCs from aged and young mice, although the angiogenic potential of BMCs with and without hypoxic preconditioning was lower in old mice compared with young mice. Conclusions: Similar responses to hypoxia by BMCs from both aged and young mice suggest that hypoxic preconditioning could be a useful method of enhancing the angiogenic potential of BMCs