CARACTERIZAREA FAZEOLINEI MODIFICATE IN VIVO

Diana MORARI, Tatiana STEPURINA, Vitalie I. ROTARI LCŞ „Biochimia Plantelor”

Rezumat

Phaseolin, the 7S seed storage protein from common beans (Phaseolus vulgaris L.), partially modified in vivo during seed germination and seedling growth was isolated from cotyledons of 6 day germinated seedlings (phaseolininvivo). SDS-PAGE showed that the pattern of fragments of phaseolin-invivo is similar to that of the phaseolin degraded by legumain - phaseolin-LLP. Native electrophoresis showed that phaseolin-invivo consists of four molecular forms. 2-D electrophoresis showed that the molecular form of phaseolin-invivo that is similar to phaseolin-LLP retains in its quaternary structure some of the fragments detected by SDS-PAGE. Phaseolin-invivo retains the property to reversibly associate/dissociate with the changes in pH. At pH 4.6 it is present in its dodecameric form while at pH 8.0 in its protomeric form. The implications of the finding that phaseolin-invivo retains the same property of native phaseolin to associate into dodecamers at acidic pHs are discussed.