O-Glycans on platelet surface are carried predominantly by a
protein subunit of size about 116 kDa
Hypotonic lysis of platelets followed by centrifugation yielded
membranes completely devoid of adhering triplets since no triplet
component was released following their sugar treatment. Western blot of
proteins from the above membranes revealed several concanavalin
A-binding N-glycosylated proteins, but only one O-glycosylated subunit
detectable by jacalin binding (Fig.5). Presence of core-1 type O-linked
oligosaccharides on this subunit was confirmed by the sugar-dependent
binding of peanut agglutinin to its desialylated form. Size of this
dominant O-glycoprotein on platelet surface was determined as 116 kDa
(Fig.5), a value close to the reported molecular weights of 120 kDa
[21], 118 kDa [22] and 125 ± 15 kDa [23] for the GPIIb
subunit, suggesting again the possibility that GPIIb/IIIa acts as the
major, if not the sole platelet receptor for anti-Gal and ABG in
triplets.