After drought treatment, marked increase in quantity of PEPcarboxylase protein in the leaves of M. cordifolium, an inducible CAM plant, was shown by SDS-PAGE and western immunoblot (Fig. 1). Further investigation with...After drought treatment, marked increase in quantity of PEPcarboxylase protein in the leaves of M. cordifolium, an inducible CAM plant, was shown by SDS-PAGE and western immunoblot (Fig. 1). Further investigation with incorporation of L-[^(35)S] methionine into leaf discs and immunoprecipitation revealed that de novo synthesis of PEP-carboxylase protein was responsible for this increase (Fig. 2).展开更多
Besides the major 250 kD PEPCase isoform, a 300 kD minor PEPCaseform was also found in Mesembryanthemum cordifolium leaves (Fig. 1 ). Byusing SDS PAGE it was found that bothisoforms were homodiners. ’The 250 kDform c...Besides the major 250 kD PEPCase isoform, a 300 kD minor PEPCaseform was also found in Mesembryanthemum cordifolium leaves (Fig. 1 ). Byusing SDS PAGE it was found that bothisoforms were homodiners. ’The 250 kDform consisted of two 100 kD subunits ,and the 300 kD form is a dimer of two110 kD subunits (Figs. 2,3). ’The discrepency between molectilar weights ofthe native enzymes and their subunitswas a result of the different molecularweight determinating methods. There fore, there is no heterodimer of PEPCase in this plant. A 1 080 kD PEPCase form was found in both saltstressed and well-watered leaf samples.This PEPCase is an octamer, and therewas no diurnal fluctuation in its abundance.展开更多
文摘After drought treatment, marked increase in quantity of PEPcarboxylase protein in the leaves of M. cordifolium, an inducible CAM plant, was shown by SDS-PAGE and western immunoblot (Fig. 1). Further investigation with incorporation of L-[^(35)S] methionine into leaf discs and immunoprecipitation revealed that de novo synthesis of PEP-carboxylase protein was responsible for this increase (Fig. 2).
文摘Besides the major 250 kD PEPCase isoform, a 300 kD minor PEPCaseform was also found in Mesembryanthemum cordifolium leaves (Fig. 1 ). Byusing SDS PAGE it was found that bothisoforms were homodiners. ’The 250 kDform consisted of two 100 kD subunits ,and the 300 kD form is a dimer of two110 kD subunits (Figs. 2,3). ’The discrepency between molectilar weights ofthe native enzymes and their subunitswas a result of the different molecularweight determinating methods. There fore, there is no heterodimer of PEPCase in this plant. A 1 080 kD PEPCase form was found in both saltstressed and well-watered leaf samples.This PEPCase is an octamer, and therewas no diurnal fluctuation in its abundance.
