The composition of seed storage proteins (SSPs) in o
live endosperm and coty
ledon has beenana
lyzed. Precursor forms of these proteins are made up of individua
l proteins, which have beenpurified to homogeneity and further named p1-p5 (20.5, 21.5, 25.5, 27.5, and 30 kDa, respective
ly).N-termina
l sequences of p1 and p2 proteins disp
layed re
levant homo
logy to the basic subunit of the11
S fami
ly of p
lant SSPs (
legumins). Two-dimensiona
l po
lyacry
lamide ge
l e
lectrophoresis experimentsa
llowed us to verify the basic character of p1 and p2 and the acidic character of p3, p4, and p5proteins. In addition, the putative presence of high
ly simi
lar isoforms or posttrans
lationa
l modificationsof these po
lypeptides was detected. As a resu
lt, a mode
l describing the putative association of p1-p5 proteins into subunits of
lpha.gif" BORDER=0>(acidic)/
le">(basic) type has been proposed. So
lubi
lity experiments haveshown that the majority of these o
live seed proteins from the 11
S storage protein fami
ly are extractedwith aqueous a
lcoho
l and on
ly partia
lly with water and di
luted sa
line so
lutions, therefore suggestingtheir simi
larity to pro
lamines. Moreover, no visib
le differences were found in either subunit compositionor 11
S proteins mass among six o
live cu
ltivars examined. This resu
lt suggests that the synthesis ofstorage proteins is high
ly conserved in this p
lant species. By using a rabbit antiserum raised to p1protein, the proteins have a
lso been immuno
loca
lized in o
live seed tissues, showing that theyaccumu
late in conspicuous protein bodies present in both the endosperm and the coty
ledon.Keywords: Coty
ledon; endosperm;
Olea europaea L.; o
live tree; protein bodies; 11
S storage protein