Addition of carbohydrate side chains at novel sites on influenza virus hemagglutinin can modulate the folding, transport, and activity of the molecule.
We have constructed and expressed a series of mutant influenza virus hemagglutinins, each containing a new consensus site for glycosylation in addition to the seven sites found on the wild-type protein. Oligosaccharide side chains were added with high efficiency at four of the five novel sites, located on areas of the protein's surface that are not normally shielded by carbohydrate. Investigations of the structure, intracellular transport, and biological activities of the mutant hemagglutinin molecules indicated that (a) supernumerary carbohydrate side chains can be used to shield or disrupt functional epitopes on the surface of hemagglutinin, and (b) the presence of an additional oligosaccharide may cause temperature-dependent defects in the transport of the glycoprotein. We discuss the addition of supernumerary oligosaccharides as a general tool for shielding chosen areas of the surface of proteins that enter or traverse the secretory pathway.
Gallagher
P
P
Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas 75235.
Henneberry
J
J
Wilson
I
I
Sambrook
J
J
Gething
M J
MJ
D000595:Amino Acid Sequence; D000956:Antigens, Viral / Q000502:physiology*; D001692:Biological Transport; D002459:Cell Fusion; D003198:Computer Simulation; D004252:DNA Mutational Analysis; D000939:Epitopes; D005455:Fluorescent Antibody Technique; D006031:Glycosylation; D006389:Hemagglutinins, Viral / Q000502:physiology*; D009980:Influenza A virus; D008562:Membrane Glycoproteins / Q000502:physiology* / Q000648:ultrastructure; D008970:Molecular Weight; D011487:Protein Conformation; D013329:Structure-Activity Relationship; D013696:Temperature
D000956:Antigens, Viral; D000939:Epitopes; D006389:Hemagglutinins, Viral; D008562:Membrane Glycoproteins