Characterization of photosystem I from spinach: effect of solution pH

• Published in: Photosynthesis research Vol. 112; no. 1; pp. 63 - 70
• Main Authors: Liu, Jianguo, Zhang, Xuefang, Wang, Meng, Liu, Jing, Cao, Meiwen, Lu, Jianren, Cui, Zhanfeng
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer-Verlag 01.04.2012; Springer Netherlands; Springer; Springer Nature B.V
• Subjects: Atomic force microscopy; Biochemistry; Biomedical and Life Sciences; Cell Membrane - chemistry; Chemical properties; Detergents - chemistry; Fluorescence; Glucosides - chemistry; Hydrogen-Ion Concentration; image analysis; Isoelectric Point; Life Sciences; Membranes; Microscopy, Atomic Force; Photosynthesis; photosystem I; Photosystem I Protein Complex - chemistry; Photosystem I Protein Complex - isolation & purification; Plant biology; Plant Genetics and Genomics; Plant Physiology; Plant Proteins - chemistry; Plant Proteins - isolation & purification; Plant Sciences; Protein Stability; Protein Structure, Secondary; Proteins; Regular Paper; Solutions - chemistry; spinach; Spinacia oleracea - chemistry; Temperature; thermal stability; Thylakoids - chemistry; Ultrafiltration - methods; Photosystem I; Membrane protein; Solution pH; Spinach; Property
• ISSN: 0166-8595; 1573-5079
• DOI: 10.1007/s11120-012-9737-6

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.