In order to create a functionalized biodegradable polymer for vascular tissue engineering application,poly(DL- lactide-co-RS-β-malic acid)(PDLLMAc)was synthesized.PDLLMAc was obtained after hydrogenolysis of poly(DL-...In order to create a functionalized biodegradable polymer for vascular tissue engineering application,poly(DL- lactide-co-RS-β-malic acid)(PDLLMAc)was synthesized.PDLLMAc was obtained after hydrogenolysis of poly(DL- lactide-co-RS-β-benzyl malolactonate)(PDLLMA),which was from the ring-opening polymerization of DL-lactide(DLLA) and RS-β-benzyl malolactonate(MA)using stannous octoate as catalyst.The copolymers were characterized by ~1H-NMR, FTIR,GPC and DSC.The tensile strength and water uptake of the copoly...展开更多
In this paper,the poly(acrylamide)hydrogel used to immobilize saccharomyces cerevisiae for asymmetric synthesis of R(-)-mandelic acid was prepared with free radical ploymerization in deionized water at room temperatur...In this paper,the poly(acrylamide)hydrogel used to immobilize saccharomyces cerevisiae for asymmetric synthesis of R(-)-mandelic acid was prepared with free radical ploymerization in deionized water at room temperature under nitrogen atmosphere.The influence of the composition of hydrogel,loading amount of cells and culture conditions on the asymmetric synthesis was investigated.Results show that PAAm hydrogel is a feasible carrier for immobilization of cells which is a potential alternative method to prepare enantiomerically pure R(-)-mandelic acid.展开更多
The protein family of 14-3-3(s) has risen to a position of higher importance as an adaptor protein in cell biology. The seven highly conserved human 14-3-3 proteins coordinate diverse cellular processes including apop...The protein family of 14-3-3(s) has risen to a position of higher importance as an adaptor protein in cell biology. The seven highly conserved human 14-3-3 proteins coordinate diverse cellular processes including apoptosis, DNA damage response, protein trafficking, and others. In liver hepatocytes, 14-3-3β binds to Ser196-phosphorilated glucose-responsive carbohydrate response element-binding protein (ChREBP) to inhibit converting excess carbohydrate to fat by regulating the nuclear/cytosol trafficking of ChREBP. Here, we report X-ray crystal structures of homodimeric mammalian 14-3-3β in its apo, Malate-bound forms. The determined apo structure was captured with one monomer in the closed state, whereas the other one had an open conformation. Strikingly, 14-3-3β binds Malate dynamically with a double-closed state, which is distinct from all previously characterized 14-3-3(s) and target ligand-binding modes. Malate docks into a first-time observed cofactor pocket located at the concaved interface of 14-3-3β helices α2, α3, α4 through mainly electrostatic and hydrogen interactions. Such a Tricarboxylic Acid Cycle intermediate Malate bond model might offer a new approach to further analyze insulin-independent 14-3-3/ChREBP pathway of de novo fat synthesis in the liver.展开更多
文摘In order to create a functionalized biodegradable polymer for vascular tissue engineering application,poly(DL- lactide-co-RS-β-malic acid)(PDLLMAc)was synthesized.PDLLMAc was obtained after hydrogenolysis of poly(DL- lactide-co-RS-β-benzyl malolactonate)(PDLLMA),which was from the ring-opening polymerization of DL-lactide(DLLA) and RS-β-benzyl malolactonate(MA)using stannous octoate as catalyst.The copolymers were characterized by ~1H-NMR, FTIR,GPC and DSC.The tensile strength and water uptake of the copoly...
文摘In this paper,the poly(acrylamide)hydrogel used to immobilize saccharomyces cerevisiae for asymmetric synthesis of R(-)-mandelic acid was prepared with free radical ploymerization in deionized water at room temperature under nitrogen atmosphere.The influence of the composition of hydrogel,loading amount of cells and culture conditions on the asymmetric synthesis was investigated.Results show that PAAm hydrogel is a feasible carrier for immobilization of cells which is a potential alternative method to prepare enantiomerically pure R(-)-mandelic acid.
文摘The protein family of 14-3-3(s) has risen to a position of higher importance as an adaptor protein in cell biology. The seven highly conserved human 14-3-3 proteins coordinate diverse cellular processes including apoptosis, DNA damage response, protein trafficking, and others. In liver hepatocytes, 14-3-3β binds to Ser196-phosphorilated glucose-responsive carbohydrate response element-binding protein (ChREBP) to inhibit converting excess carbohydrate to fat by regulating the nuclear/cytosol trafficking of ChREBP. Here, we report X-ray crystal structures of homodimeric mammalian 14-3-3β in its apo, Malate-bound forms. The determined apo structure was captured with one monomer in the closed state, whereas the other one had an open conformation. Strikingly, 14-3-3β binds Malate dynamically with a double-closed state, which is distinct from all previously characterized 14-3-3(s) and target ligand-binding modes. Malate docks into a first-time observed cofactor pocket located at the concaved interface of 14-3-3β helices α2, α3, α4 through mainly electrostatic and hydrogen interactions. Such a Tricarboxylic Acid Cycle intermediate Malate bond model might offer a new approach to further analyze insulin-independent 14-3-3/ChREBP pathway of de novo fat synthesis in the liver.
基金Acknowledgements We greatly acknowledge the financial support from the National Natural Science Foundation of China （grant No. 30970788, No.81271687）.
