THE UNIVERSITY OF MANITOBA STUDIES ON OVINE PLACINTAL ...

Chiiracteri z_âti on
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Analytical Polyacrvlamide Gel tl ectrophore3i s
Flgure 11 shows the protein pattern of the purified oPL
preparation upon electrophoresis run under (a) acidic (pH 4.3_4.S) and
(¡) alkal ine (pH 9.3-9.a) conditions respectively. Under the
acidic conditìon, only one stajned band was visibìe. An unstained
gel , ìn which oPL hadSsg. separated in a similar manner, was divided
and consecutive ge1 segments were eluted and assayed for opL by RRA-
GH, GH-like activjty was detected Jn the eluants corresponding to the
stained band. Hov¡ever, when it was subjected to polyacrylanide geì
e'lectrophores i s at alkaline pH (Fig. 'l lb), three stained bands were
visíble. l^lhen a duplicate unstained gel was divided and the segments
eluted and assayed by RRA-GH, GH-like activities were detected in the
eluants correspondìng to two stained bands . ñear the ônode
with the highest GH-like activity associat¡d with the darkest band.
Analytical Ge1 Isoelectri cal -focusing
When the purified oPL preparation was analyzed by analyt.ical
gel isoelectrìc focusing as shown in Figure 12, the opL preparation
displayed two major and s¡g ¡Ì¡6¡ þ¿¡d5.When a duplicate ge'l that was
not stained was divided fnto segments and e'luted with buffer, then
assayed by RRA-GH as shown in the f.igure, GH-like activity was found
in the eluants coincide wìth the two bands near the cathode. S.imilarìy,
when a highly purified human placenta'l lactogen(hpl,NIH, 951 electro-
phoreticalìy pure) was subJected to the same run, at least 3 bands were seen,