Enzymatic labeling of biologically active envelope glycoprotein gp120 of HIV-1.
We have found that the envelope glycoprotein gp120 of HIV-1 can be modified extensively by enzymatic oxidation of oligosaccharide chains without diminishing binding to its natural receptor, CD4. Using affinity purified galactose oxidase, over 20 sites per gp120 molecule were converted to chemically reactive aldehydes, as measured by 3H-BH4 reduction, while the conformation-dependent CD4 binding site remained intact. In contrast, periodate oxidation completely destroyed CD4 binding while producing fewer sites. Enzymatically labeled, biologically active gp120 should facilitate biochemical studies of receptor binding and viral inactivation by neutralizing antibodies.
Berkower
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I
Division of Allergenics and Parasitology Center for Biologics, FDA, NIH Campus, Bethesda, MD 20892.
Murphy
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D
D001894:Borohydrides / Q000737:chemistry; D015704:CD4 Antigens / Q000378:metabolism; D005692:Galactose Oxidase / Q000302:isolation & purification / Q000378:metabolism; D015488:HIV Antigens / Q000276:immunology; D015699:HIV Envelope Protein gp120 / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism; D009439:Neuraminidase / Q000378:metabolism; D010084:Oxidation-Reduction; D013329:Structure-Activity Relationship
D001894:Borohydrides; D015704:CD4 Antigens; D015488:HIV Antigens; D015699:HIV Envelope Protein gp120; C025364:sodium borohydride; D005692:Galactose Oxidase; D009439:Neuraminidase