Chemical and Biomolecular Engineering, Department of


Date of this Version


Document Type



Glycobiology vol. 18 no. 7 pp. 526–539, 2008


Copyright The Author 2008. Published by Oxford University Press. All rights reserved.


Glycosylation of recombinant proteins is of particular

importance because it can play significant roles in the

clinical properties of the glycoprotein. In this work, the

N-glycan structures of recombinant human Factor IX (tg-

FIX) produced in the transgenic pig mammary gland were

determined. Themajority of theN-glycans of transgenic pigderived

Factor IX (tg-FIX) are complex, bi-antennary with

one or two terminal N-acetylneuraminic acid (Neu5Ac) moieties.

We also found that the N-glycan structures of tg-FIX

produced in the porcine mammary epithelial cells differed

with respect to N-glycans from glycoproteins produced in

other porcine tissues. tg-FIX contains no detectableNeu5Gc,

the sialic acid commonly found in porcine glycoproteins produced

in other tissues.Additionally,wewere unable to detect

glycans in tg-FIX that have a terminal Galα(1,3)Gal disaccharide

sequence, which is strongly antigenic in humans.

The N-glycan structures of tg-FIX are also compared to the

publishedN-glycan structures of recombinant human glycoproteins

produced in other transgenic animal species.While

tg-FIX contains only complex structures, antithrombin III

(goat), C1 inhibitor (rabbit), and lactoferrin (cow) have both

high mannose and complex structures. Collectively, these

data represent a beginning point for the future investigation

of species-specific and tissue/cell-specific differences in

N-glycan structures among animals used for transgenic animal