Human immunodeficiency virus type 1 envelope glycoprotein is modified by O-linked oligosaccharides.
The human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein has been shown to be extensively modified by N-linked glycosylation; however, the presence of O-linked carbohydrates on the glycoprotein has not been firmly established. We have found that enzymatic deglycosylation of the HIV-1 envelope glycoprotein with neuraminidase and O-glycosidase results in a decrease in the apparent molecular weight of the envelope glycoprotein. This result was observed in both vaccinia virus recombinant-derived envelope glycoproteins and glycoproteins derived from the IIIB, SG3, and HXB2, strains of HIV-1. The decrease in molecular weight was also observed when the envelope glycoprotein had been deglycosylated with N-glycanase F after treatment with neuraminidase and O-glycosidase, indicating that the decrease in apparent molecular weight was not attributable to the removal of N-linked carbohydrate. Treatment with neuraminidase, O-glycosidase, and N-glycanase F was found to be necessary to remove all radiolabel from [3H]glucosamine-labelled envelope glycoprotein, a result seen for both recombinant and HIV-1-derived envelope glycoprotein. [3H]glucosamine-labelled carbohydrates liberated by O-glycosidase treatment were separated by paper chromatography and were found to be of a size consistent with O-linked oligosaccharides. We, therefore, conclude that the HIV-1 envelope glycoprotein is modified by the addition of O-linked carbohydrates.
Bernstein
H B
HB
Department of Microbiology, University of Alabama at Birmingham 35294.
Tucker
S P
SP
Hunter
E
E
Schutzbach
J S
JS
Compans
R W
RW
D000581:Amidohydrolases / Q000494:pharmacology; D000818:Animals; D002478:Cells, Cultured; D002854:Chromatography, Paper; D015686:Gene Products, env / Q000737:chemistry* / Q000187:drug effects / Q000235:genetics; D005944:Glucosamine / Q000378:metabolism; D006023:Glycoproteins / Q000737:chemistry* / Q000187:drug effects / Q000235:genetics; D006031:Glycosylation; D015497:HIV-1 / Q000737:chemistry*; D006801:Humans; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase / Q000494:pharmacology; D008970:Molecular Weight; D009439:Neuraminidase / Q000494:pharmacology; D009844:Oligosaccharides / Q000737:chemistry*; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase; D011134:Polysaccharides / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000187:drug effects
D015686:Gene Products, env; D006023:Glycoproteins; D009844:Oligosaccharides; D011134:Polysaccharides; D011994:Recombinant Proteins; D009439:Neuraminidase; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase; D000581:Amidohydrolases; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase; D005944:Glucosamine