Chromatographic properties of pyruvate:fructose-6-phosphate 1-phosphotransferase (PFP) from leaves of a CAM plant, pineapple (Ananas comosus),Chromatographic properties of pyruvate:fructose-6-phosphate 1-phosphotransferase (PFP) from leaves of a CAM pl

Abstract

PFP has been recognized as a regulating enzyme of the alternative glycolysis in the plants and PEP synthesis in some CAM plants. In this study, chromatographic traits of PFP of pineapple leaves were examined. Pineapple plants were grown in the greenhouse and the experimental plants were moved to the growth-chamber at 10 days before each experiment. Conditions in the growth-chamber were as follows: daylength was 12 hrs from 8:00 to 20:00; PAR on the leaves ca.330µmol/m2/s; air humidity 60%; air temperature of day and night 30°C and 20°C. Extraction was done at 17:00 as day form and at 24:00 as night form, respectively. PFP of pineapple leaves showed different isoelectric points in day and night, such as two points of pH 4.88 and 5.34 of day form and one point of pH 4.80 of night form. Day form PFP also was eluted as two individual peaks on DEAE-cellulose chromatogram (Protein-Pak, DEAE 8HR, 5x100mm, Waters) with non-liner gradient of KCl, and the protein in each peak showed different elution time on molecular sieve chromatogram (Protein-Pak 300, 8x300mm, Waters), such as 14.23 and 12.51 min. As described above, it was suggested that PFP protein of pineapple leaves existed as different molecular aggregation state in day and night.