Xuefang Zhang

Publications (2)6.49 Total impact

• Article: Characterization of photosystem I from spinach: effect of solution pH.

  Jianguo Liu, Xuefang Zhang, Meng Wang, Jing Liu, Meiwen Cao, Jianren Lu, Zhanfeng Cui
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  ABSTRACT: Our previous work has demonstrated the isolation of photosystem I (PSI) from spinach using ultrafiltration with a final purity of 84%. In order to get a higher purity of PSI and more importantly to develop a practical bioseparation process, key physiochemical properties of PSI and their dependence on operational parameters must be assessed. In this study, the effect of solution pH, one of the most important operating parameters for membrane process, on the property of PSI was examined. Following the isolation of crude PSI from spinach using n-dodecyl-beta-D: -maltoside as detergent, the isoelectric point, aggregation size, zeta potential, low-temperature fluorescence, atomic force microscopy imaging, secondary structure, and thermal stability were determined. Solution pH was found to have a significant effect on the activity, aggregation size and thermal stability of PSI. The results also suggested that the activity of PSI was related to its aggregation size.
  Photosynthesis Research 04/2012; 112(1):63-70. · 3.24 Impact Factor
• Article: A novel membrane based process to isolate photosystem-I membrane complex from spinach.

  Jianguo Liu, Mengmeng Yin, Meng Wang, Xuefang Zhang, Baosheng Ge, Shuang Liu, Jianren Lu, Zhanfeng Cui
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  ABSTRACT: The isolation of photosystem-I (PS-I) from spinach has been conducted using ultrafiltration with 300 kDa molecular weight cut-off polyethersulfone membranes. The effects of ultrafiltration operating conditions on PS-I activity were optimized using parameter scanning ultrafiltration. These conditions included solution pH, ionic strength, stirring speed, and permeate flux. The effects of detergent (Triton X-100 and n-dodecyl-beta-D-maltoside) concentration on time dependent activity of PS-I were also studied using an O(2) electrode. Under optimized conditions, the PS-I purity obtained in the retentate was about 84% and the activity recovery was greater than 94% after ultrafiltration. To our knowledge, this is the first report of the isolation of a membrane protein using ultrafiltration alone.
  Photosynthesis Research 02/2011; 107(2):187-93. · 3.24 Impact Factor