title: A novel membrane based process to isolate photosystem-I membrane complex from spinach.
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.
authors.affiliation: Center for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao 266555, People's Republic of China. jianguoliu@upc.edu.cn
authors.forename: Jianguo
authors.initials: J
authors.lastname: Liu
authors.forename: Mengmeng
authors.initials: M
authors.lastname: Yin
authors.forename: Meng
authors.initials: M
authors.lastname: Wang
authors.forename: Xuefang
authors.initials: X
authors.lastname: Zhang
authors.forename: Baosheng
authors.initials: B
authors.lastname: Ge
authors.forename: Shuang
authors.initials: S
authors.lastname: Liu
authors.forename: Jianren
authors.initials: J
authors.lastname: Lu
authors.forename: Zhanfeng
authors.initials: Z
authors.lastname: Cui
mesh_terms: D002462:Cell Membrane / Q000737:chemistry*; D002734:Chlorophyll / Q000378:metabolism; D003902:Detergents / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D009994:Osmolar Concentration; D010539:Permeability; D045331:Photosystem I Protein Complex / Q000302:isolation & purification*; D010940:Plant Proteins / Q000302:isolation & purification*; D011108:Polymers; D018724:Spinacia oleracea / Q000737:chemistry*; D013450:Sulfones; D014462:Ultrafiltration / Q000379:methods*
chemical_list: D003902:Detergents; D045331:Photosystem I Protein Complex; D010940:Plant Proteins; D011108:Polymers; D013450:Sulfones; D002734:Chlorophyll; C022840:polyether sulfone