A yeast strain R6 was obtained by the method of thiamine（VB1） auxotrophic negative selection from the edible oil-polluted soil in Zibo, China. Physiological and biochemical experiments revealed that strain R6 shared...A yeast strain R6 was obtained by the method of thiamine（VB1） auxotrophic negative selection from the edible oil-polluted soil in Zibo, China. Physiological and biochemical experiments revealed that strain R6 shared common feature with Rhodotorula mucilaginosa according to the API 20 C AUX yeast identification system which has been tested previously. Furthermore, the 18 S r DNA gene of strain R6 was amplified and sequenced. Phylogenetic analysis based on the 18 S r DNA sequence and the relatives indicated that R6 shared 99% homologies with the members of R. mucilaginosa, suggesting that strain R6 belonged to R. mucilaginosa.Investigation showed that strain R6 possessed the capacity of accumulating exocellular alpha-ketoglutaric acid（alpha-KG）. Finally, the fermentation conditions of R6 to accumulate alpha-KG was optimized by controlling each single fermenting variable and detected through high performance liquid chromatography（HPLC）. Results showed that both VB1 and Ca CO3 in fermentation medium were the key factors influencing the cumulant of alpha-KG. The discovery of natural auxotrophic strain R6 not only broadened the microbial resource which can achieve lots of alpha-KG production through fermentation, but also laid a foundation for further fermentation regulation to achieve excessive alpha-KG accumulation.展开更多
Dynamic regulation of histone methylation/demethylation plays an important role during development. Mutations and truncations in human plant homeodomain （PHD） finger protein 8 （PHF8） are associated with X-linked m...Dynamic regulation of histone methylation/demethylation plays an important role during development. Mutations and truncations in human plant homeodomain （PHD） finger protein 8 （PHF8） are associated with X-linked mental retardation and facial anomalies, such as a long face, broad nasal tip, cleft lip/cleft palate and large hands, yet its molecular function and structural basis remain unclear. Here, we report the crystal structures of the catalytic core of PHF8 with or without α-ketoglutarate （α-KG） at high resolution. Biochemical and structural studies reveal that PHF8 is a novel histone demethylase specific for di- and mono-methylated histone H3 lysine 9 （H3K9me2/1）, but not for H3K9me3. Our analyses also reveal how human PHF8 discriminates between methylation states and achieves sequence specificity for methylated H3K9. The in vitro demethylation assay also showed that the F279S mutant observed in clinical patients possesses no demethylation activity, suggesting that loss of enzymatic activity is crucial for pathogenesis of PHF8 patients. Taken together, these results will shed light on the molecular mechanism underlying PHF8-associated developmental and neurological diseases.展开更多
This research was to examine if rice (Oryza sativa L.), a monocotyledon of angiosperm, was able to synthesize chlorophyll (Chl) in complete darkness. Five-cm-tall etiolated seedlings of rice were used as starting mate...This research was to examine if rice (Oryza sativa L.), a monocotyledon of angiosperm, was able to synthesize chlorophyll (Chl) in complete darkness. Five-cm-tall etiolated seedlings of rice were used as starting materials and treated with or without various concentrations of glucose and/or δ-aminolevulinic acid (ALA) in the dark. Leaves harvested at the indicated time were determined for their contents of Chl, protoporphyrin Ⅸ (Proto), Mg-protoporphyrin Ⅸ (Mg-Proto) and protochlorophyllide (Pchlide). The mole percentage of porphyrin was calculated. The Chl content in the etiolated rice seedlings slightly increased from about 2.5 μg/g to 7.5 μg/g within 12 d in the dark, but the total Chl of dark-grown rice increased from 0.36 μg/g to 3.6 μg/g. While the mole percentages of Proto, Mg-Proto and Pchlide in the dark-grown seedlings without any treatment were about 65%, 27.5% and 7.5% at the beginning, respectively, those in the light-grown seedlings were about 42.5%, 35% and 22.5%, respectively. The mole percentage of porphyrin of etiolated seedlings resumed its normal ratio within 2 d after treatment with glucose. While the Chl content of etiolated seedlings grown in culture solution with 3% and 6% glucose increased 2.5 and 4.0 folds, respectively, those with 3% and 6% glucose and 1 mmol/L ALA increased 22 and 24 folds, respectively. It is concluded that angiosperm might be able to synthesize a small amount of Chl in complete darkness, that either glucose or ALA could stimulate dark Chl synthesis in angiosperm, and that a combination of glucose and ALA exhibited an additional effect. It is still unknown and remains to be further explored what is the mechanism of the effect of glucose and ALA on the Chl synthesis of rice in the dark.展开更多
By using the laser-monitoring technique,solid-liquid equilibrium data of glutaric acid in cyclohexanol,cyclohexanone,their five mixed solvents and acetic acid were measured within the temperature range from 292.15K to...By using the laser-monitoring technique,solid-liquid equilibrium data of glutaric acid in cyclohexanol,cyclohexanone,their five mixed solvents and acetic acid were measured within the temperature range from 292.15K to 354.60K by dynamic method.Empirical formula and λh equation were used to correlate the solubilities of glutaric acid in eight solvents.The maximal average relative deviations were 1.15% and 2.20% by using the em-pirical formula and λh equation to correlate the solubility data.The results showed that the empirical formula and λh model could correlate the solubility data of glutaric acid in eight solvents.In addition,the solubility data of glutaric acid in five mixtures(cyclohexanone+cyclohexanol)could be predicted with the NRTL equation utilizing the pa-rameters of the binary systems.The total average relative deviation was 3.60%.The results indicate that the NRTL equation could well predict the solubilities of glutaric acid in the mixed solvents of cyclohexanone and cyclohexanol.展开更多
Objective To investigate the efficacy and safety of photodynamic therapy （PDT） with topical 5-aminolaevulinic acid （ALA） on cervical condylomata acuminata. Methods Patients with cervical condylomata （n=30） were...Objective To investigate the efficacy and safety of photodynamic therapy （PDT） with topical 5-aminolaevulinic acid （ALA） on cervical condylomata acuminata. Methods Patients with cervical condylomata （n=30） were allocated into primary and recurrent group, and were given topical ALA under occlusive dressing for 3 hours followed by irradiation with semiconductor laser at a dose of 100 Jcm 2 and a power of 100 roW. The treatment was repeated 7 days later if the lesion was not completely removed after the first treatment. Complete response rate and recurrence rate of wart lesions as well as rate of adverse reaction were analyzed. Results The total complete response rate of PDT was 100% and the total recurrence rate was 5% after 3 months of follow-up. Recurrence rate of recurrent group was significantly lower than that of prior managements （100%, P〈0.01）. The side effects of PDT in patients mainly included mild burning and/or stinging restricted to the illuminated areas, and was significant lower than their own control （25% vs. 100%, P〈0.05）. Conclusion Compared with conventional therapies, topical application of ALA-PDT is a simple, effective, safe, well-tolerated, and low recurrence rate treatment for cervical condylomata acuminata.展开更多
基金Supported by the Natural Science Foundation of Shandong Province,China(ZR2010CQ017)Program of Young Teachers Development of Shandong University of Technology~~
文摘A yeast strain R6 was obtained by the method of thiamine（VB1） auxotrophic negative selection from the edible oil-polluted soil in Zibo, China. Physiological and biochemical experiments revealed that strain R6 shared common feature with Rhodotorula mucilaginosa according to the API 20 C AUX yeast identification system which has been tested previously. Furthermore, the 18 S r DNA gene of strain R6 was amplified and sequenced. Phylogenetic analysis based on the 18 S r DNA sequence and the relatives indicated that R6 shared 99% homologies with the members of R. mucilaginosa, suggesting that strain R6 belonged to R. mucilaginosa.Investigation showed that strain R6 possessed the capacity of accumulating exocellular alpha-ketoglutaric acid（alpha-KG）. Finally, the fermentation conditions of R6 to accumulate alpha-KG was optimized by controlling each single fermenting variable and detected through high performance liquid chromatography（HPLC）. Results showed that both VB1 and Ca CO3 in fermentation medium were the key factors influencing the cumulant of alpha-KG. The discovery of natural auxotrophic strain R6 not only broadened the microbial resource which can achieve lots of alpha-KG production through fermentation, but also laid a foundation for further fermentation regulation to achieve excessive alpha-KG accumulation.
基金Supplementary information is linked to the online version of the paper on the Cell Research website.Acknowledgments We thank Dr Dawei Li （China Agricultural University） for generously providing us with the experimental conditions during the early stages of this project. We thank Dr Ruiming Xu （Institute of Biophysics, Chinese Academy of Sciences） for critical reading of this manuscript and advice. We thank Dr Pinchao Mei （Chinese Academy of Medical Sciences and Peking Union Medical College）, Xinqi Liu （Nankai University） and Jiemin Wong （East China Normal University） for discussions and advice. The synchrotronradiation experiments were performed at Shanghai Synchrotron Radiation Facility （SSRF） and NE3A in the Photon Factory. Z.C. is supported by the National Basic Research Program of China （973 Program, 2009CB825501）, the National Natural Science Foundation of China （30870494 and 90919043）, the New Century Excellent Talents in University （NCET-07-0808） and the Innovative Project of SKLAB. S. H. is supported by the National Key Laboratory Special Fund 2060204. Z. D. is supported by the National Natural Science Foundation of China （J0730639）.
文摘Dynamic regulation of histone methylation/demethylation plays an important role during development. Mutations and truncations in human plant homeodomain （PHD） finger protein 8 （PHF8） are associated with X-linked mental retardation and facial anomalies, such as a long face, broad nasal tip, cleft lip/cleft palate and large hands, yet its molecular function and structural basis remain unclear. Here, we report the crystal structures of the catalytic core of PHF8 with or without α-ketoglutarate （α-KG） at high resolution. Biochemical and structural studies reveal that PHF8 is a novel histone demethylase specific for di- and mono-methylated histone H3 lysine 9 （H3K9me2/1）, but not for H3K9me3. Our analyses also reveal how human PHF8 discriminates between methylation states and achieves sequence specificity for methylated H3K9. The in vitro demethylation assay also showed that the F279S mutant observed in clinical patients possesses no demethylation activity, suggesting that loss of enzymatic activity is crucial for pathogenesis of PHF8 patients. Taken together, these results will shed light on the molecular mechanism underlying PHF8-associated developmental and neurological diseases.
文摘This research was to examine if rice (Oryza sativa L.), a monocotyledon of angiosperm, was able to synthesize chlorophyll (Chl) in complete darkness. Five-cm-tall etiolated seedlings of rice were used as starting materials and treated with or without various concentrations of glucose and/or δ-aminolevulinic acid (ALA) in the dark. Leaves harvested at the indicated time were determined for their contents of Chl, protoporphyrin Ⅸ (Proto), Mg-protoporphyrin Ⅸ (Mg-Proto) and protochlorophyllide (Pchlide). The mole percentage of porphyrin was calculated. The Chl content in the etiolated rice seedlings slightly increased from about 2.5 μg/g to 7.5 μg/g within 12 d in the dark, but the total Chl of dark-grown rice increased from 0.36 μg/g to 3.6 μg/g. While the mole percentages of Proto, Mg-Proto and Pchlide in the dark-grown seedlings without any treatment were about 65%, 27.5% and 7.5% at the beginning, respectively, those in the light-grown seedlings were about 42.5%, 35% and 22.5%, respectively. The mole percentage of porphyrin of etiolated seedlings resumed its normal ratio within 2 d after treatment with glucose. While the Chl content of etiolated seedlings grown in culture solution with 3% and 6% glucose increased 2.5 and 4.0 folds, respectively, those with 3% and 6% glucose and 1 mmol/L ALA increased 22 and 24 folds, respectively. It is concluded that angiosperm might be able to synthesize a small amount of Chl in complete darkness, that either glucose or ALA could stimulate dark Chl synthesis in angiosperm, and that a combination of glucose and ALA exhibited an additional effect. It is still unknown and remains to be further explored what is the mechanism of the effect of glucose and ALA on the Chl synthesis of rice in the dark.
文摘By using the laser-monitoring technique,solid-liquid equilibrium data of glutaric acid in cyclohexanol,cyclohexanone,their five mixed solvents and acetic acid were measured within the temperature range from 292.15K to 354.60K by dynamic method.Empirical formula and λh equation were used to correlate the solubilities of glutaric acid in eight solvents.The maximal average relative deviations were 1.15% and 2.20% by using the em-pirical formula and λh equation to correlate the solubility data.The results showed that the empirical formula and λh model could correlate the solubility data of glutaric acid in eight solvents.In addition,the solubility data of glutaric acid in five mixtures(cyclohexanone+cyclohexanol)could be predicted with the NRTL equation utilizing the pa-rameters of the binary systems.The total average relative deviation was 3.60%.The results indicate that the NRTL equation could well predict the solubilities of glutaric acid in the mixed solvents of cyclohexanone and cyclohexanol.
文摘Objective To investigate the efficacy and safety of photodynamic therapy （PDT） with topical 5-aminolaevulinic acid （ALA） on cervical condylomata acuminata. Methods Patients with cervical condylomata （n=30） were allocated into primary and recurrent group, and were given topical ALA under occlusive dressing for 3 hours followed by irradiation with semiconductor laser at a dose of 100 Jcm 2 and a power of 100 roW. The treatment was repeated 7 days later if the lesion was not completely removed after the first treatment. Complete response rate and recurrence rate of wart lesions as well as rate of adverse reaction were analyzed. Results The total complete response rate of PDT was 100% and the total recurrence rate was 5% after 3 months of follow-up. Recurrence rate of recurrent group was significantly lower than that of prior managements （100%, P〈0.01）. The side effects of PDT in patients mainly included mild burning and/or stinging restricted to the illuminated areas, and was significant lower than their own control （25% vs. 100%, P〈0.05）. Conclusion Compared with conventional therapies, topical application of ALA-PDT is a simple, effective, safe, well-tolerated, and low recurrence rate treatment for cervical condylomata acuminata.
