
Biotechnology and Applied Biochemistry (1998) 28, (3945) (Printed in Great Britain)
O-Mannosylation of Pichia pastoris cellular and recombinant proteins
Joseph G. Duman*1, Robert G. Miele*, Hong Liang, Davida K. Grella*, Kim Lee Sim, Francis J. Castellino* and Roger K. Bretthauer*2
*Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, U.S.A., and EntreMed, 9610 Medical Center Drive, Suite 200, Rockville, MD 20850, USA
Abbreviations used: HPAEC, high-pH anion-exchange chromatography; K14,
kringles 14; PAD, pulsed amperometric detector.1Present
address: Department of Molecular and Cell Biology, University of California
at Berkeley, Berkeley, CA 94720, U.S.A.
2To whom correspondence should be addressed.
O-linked saccharides were released from a major cell wall
glycoprotein and from cellular mannanprotein complexes obtained from
Pichia pastoris cells. Analysis by a variety of chromatographic
methods and exoglycosidase digestions revealed the presence of mannose
and (a1-2)-linked dimer, trimer
and tetramer saccharides of mannose. The recombinant kringle 14 domain
of human plasminogen expressed in P. pastoris was
subjected to hydrazinolysis of both O- and N-linked saccharides. Only a
very small quantity of N-linked oligosaccharides was present on the Asn289
consensus site. The major products were O-linked (a1-2)-linked
mannans, containing dimeric, trimeric, tetrameric and pentameric oligosaccharides
with the major amount of the total saccharides being distributed approximately
equally between the dimer and trimer components. These results show that
short O-linked saccharides of mannose containing (a1-2)
glycosidic linkages are present in P. pastoris cells
and expressed proteins.
Received 26 February 1998; accepted 8 March 1998
Portland Press Ltd © 1998
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