Development of α-galactosidase isoenzymes in chickpea seeds

Abstract

The development of alpha galactosidase isoenzymes in maturing and germinating Cicer arietinum seeds was investigated. The relative activities of α-galactosidase I (high molecular weight form, M r = 149 000) and α-galactosidase II (low molecular weight form, M r = 52 000) varied with the physiological state of the seed. During the early period of seed development (up to 10th day after flowering) mostly α-galactosidase II was formed accounting for about 92% of the total activity and less than 10% of α-galactosidase I activity was present. After this stage of development the proportion of the activity of α-galactosidase I increased and the α-galactosidase II activity decreased concomitantly with seed maturation. In fully mature seeds (40 days after flowering) the α-galactosidase I activity was highly predominant (about 94% of the total activity) with only very little amount (about 6%) of α-galactosidase II activity. In germinating seeds the pattern of activity of the α-galactosidase isoenzymes was completely reversed and α-galactosidase II increased with germination period with a concomitant decrease in the activity of α-galactosidase I. The in vivo interconversion of α-galactosidase I and α-galactosidase II during the maturation and germination of Cicer arietinum seeds is proposed.